Seed packets have tons of useful information and it is important to look at all the information over just a pretty picture. Pretty much all seed packets will have the following information on them. Reading seed packets not only helps you become a better gardener but it will also help you learn about the different vegetables and varieties that you grow.
First when you are planting your seeds make sure to hold onto your seed packet! It is very easy to forget which of your varieties did great and which didn’t (drawing a quick little map of your growing area also helps).
Days to Maturity
This is the time from germination to when you can harvest from the plant. These can range quite a bit between different varieties. This is an important measure when thinking about the timing of your garden. If you are planting cool-season plants a little later than you should, looking for plants and varieties that have short days to maturity (DTM) is ideal.
Germination/Days to Emergence
On the back of most seed packets you will see germination or days to emergence window. This ranges from a few days to up to 30 days depending on your vegetables. This is very helpful when figuring out if some of your seeds didn’t germinate. Remember this is an estimate based on ideal conditions. Make sure to read the planting directions.
Seed Depth
Some seed packets will have seed depth but if yours doesn’t the rule of thumb is to plant no deeper than twice a seed’s diameter. This will range from planting seeds on top of moist soil to about 1 inch in depth. It is always better to lean towards planting too shallow than too deep.
Spacing/Thin to
Packets will often provide how far apart to place seeds as spacing but occasionally they will phrase it as “thin too”. Whenever planting seeds it’s best to plant 2-3 seeds per recommended spacing and then once the “true” leaves appear to thin them to 1 plant using a pair of scissors (don’t pull them out).
How to Plant
This information is usually separate from the spacing, emergence, and depth information. It is often in more of a paragraph on the back of the seed packet. It is very important to read this information. It will let you know if you can plant these outdoors, have to start them inside, or if you have to do more advanced techniques such as soaking, cold stratifying, or scaring the seeds.
When to Plant
This information is usually nearby the How to Plant information. It is always based on the first and last frost dates of the year. It will often say things such as “after danger of frost, sow outdoors” or “4 weeks before the last frost date”.
You can also use a planting calendar to help with figuring out when to start planting.
Expiration date
Every seed packet has an expiration date similar to how food has expiration dates. Often they are set to expire about 1 year after being packed. The expiration date on the packet has little to do with the actual expiration of the seeds. Most seeds when kept in a cool dry place can last years without losing much germination. Even with seeds that have been expired for years, it is often that only 5-15% of the seeds will not germinate. So if you are using seeds that are a few years expired, don’t throw them, just throw a few extra seeds to guarantee germination.
Variety Description
Often seed packets will also have a description of the seed variety it contains. This is like the sales pitch for what makes this variety different from any other variety of that crop. This is where you will learn if the variety is more resistant to pest or disease, more heat or cold tolerant, faster growing, or other things that would make it unique in comparison to other varieties. Although this section can be very helpful and important it is also vital to know what standard they are using as a comparison. As an example we were looking at a variety the other day and at first were excited because it claimed to be very cold tolerant. Then we read the rest of the description where it said something along the lines of “this super cold tolerant variety even survives when we have one of our big winter storms where temperatures can plunge below….20F.” So just because something is considered cold tolerant somewhere else doesn’t mean it will survive our cold here. This can also be the case with disease resistance. If a variety claims to be very resistant to fungal diseases but the seed company you are getting it from is in the southwest where it’s dry and isn’t very humid (aka there isn’t much fungal disease to begin with) it might still get fungal disease here.
This time of year there are fallen leaves everywhere, sometimes literally bags of them. Although many people consider leaves a nuisance to get rid of, if you are a gardener you should see them as an opportunity to improve your garden for free! Fall leaves are very high in carbon and so have several uses in the garden.
Leaves make a fantastic mulch in the garden, especially if they have been chopped up by a mulcher or lawnmower as they are less likely to blow away. Like any mulch they help to encourage beneficial soil life, suppress weeds, and maintain soil moisture. More so than other mulches though leaves are great at encouraging beneficial soil fungal growth which many garden soils are deficient in.
If you have more than you need as mulch they are also great to have on hand to add to your compost pile when you need more browns. They can also be piled up on their own and after a year will break down into a special type of highly fungal compost called leaf mold.
Two of our great volunteers digging up sweet potatoes
Anxious to harvest sweet potatoes? Hold off! While you can technically harvest as soon as the tubers reach a decent size, the longer they are in the soil the sweeter and higher in vitamin content the sweet potatoes will be.⠀
Ideally, gardeners should wait until right before the first frost to harvest to achieve the best flavor. This requires you to watch for when frost is predicted and harvest right before that. Sweet potatoes can survive a frost but since they are a tropical plant, there is always the risk that a frost will kill the vine which will cause them to start rotting in the ground. (We typically harvest our sweet potatoes in late October depending on the timing of the first frost.)
The first step to sweet potato harvest is to remove the leaves and vines so you can find the roots.
While sweet potatoes can be eaten straight from the ground, you are likely to be disappointed in the flavor. Curing triggers the sugar-producing enzymes and heals nicks, so skipping this step results in starchy, tasteless sweet potatoes with limited shelf life.
Sweet potatoes curing in our hoophouse
Curing is a two step process. First, leave the tubers in the sun for several hours to dry the skin in order to prevent rotting during the next step. Then move the potatoes to a warm, humid place for 4-10 days. This is when the starch is converted to sugar. Ideal conditions for this step are 85-90°F and 85% humidity. A hoop house usually provides optimal conditions but a pantry with a small bucket of water and space heater will achieve this (keep an eye on the temperature). The closer you get to those ideals the better but those two options aren’t always the most practical for gardeners. We have also seen success form those who lay their sweet potatoes out in a sunroom or porch where there is plenty of air and protected from rain. We have even met people who have had success laying them on their dining room table with a fan running. No matter how you do it make sure to regularly check the sweet potatoes and get rid of any that are spoiling. At the end of the curing process, place them in a cool spot for storage. Ideal conditions are 55-60°F and 75% humidity. Basements frequently approximate these conditions.
Cover crops have many benefits for the garden. A cover crop is simply a plant grown, not to harvest, but for its benefits to the soil. You can grow cover crops anytime that you have a spot in the garden that doesn’t have a crop growing in it. Fall and winter are a great time to have cover crops in St. Louis, as the garden is usually bare unless you are growing some type of overwintering crop like garlic.
Cover crops have the ability to improve soil quality by adding organic matter and nitrogen. They also cover the soil surface, meaning less erosion and fewer weeds will germinate. Possibly the biggest benefit that cover crops have is that they feed the beneficial microorganisms in your garden soil. These organisms feed off the compounds that living roots exude into the soil and dead organic matter as mulch. Feeding these organisms improves nutrient availability and soil structure, making it easier to dig and easier for water to absorb into the soil.
In the past we have offered several types of cover crops made of single species or a blend of two species but increasing research on cover crops has shown that having more species in your mix increases the benefits of cover crops. In addition, our increasingly warm winters have meant that cover crops that used to be killed by the winter are now surviving the winter more years than not. Due to both of these facts we have changed our cover crop offerings to just two blends to simplify things and increase the effectiveness of the cover crops.
The first blend is the “winter kill blend.” This is a blend of 4 species of cover crops that were selected to die when the coldest part of winter comes. This type of cover crop should be planted in September so there is enough time for the cover crop to grow before the cold kills them. The winter kill blend can be a great choice if you don’t want to have to worry about killing the cover crop in the spring. It is also the best option if you want to plant cool season crops where the cover crops will be growing. This blend includes oats, berseem clover, phacelia, and tillage radish. Oats are particularly good at adding carbon to the soil and feeding beneficial organisms. Berseem clover is one of the best nitrogen fixers so it can add fertility to the soil. Phacelia blooms over a long period, helping to feed and sustain beneficial insects in your garden. Tillage radishes wide arching leaves help to quickly cover the soil, reducing weeds, and their large tap roots help to break up compaction and increase water infiltration.
The second blend is our “overwintering blend.” The “overwintering blend” is a combination of 4 cover crops that were selected to reliably survive our winter. Overwintering cover crops can be a great choice if warm season crops are more important in your garden. This blend can be planted as late as mid-October, right around when you are ripping out your warm season crops. It then grows throughout the winter and spring and is ready to be killed or removed around the end of April, just in time to plant your warm season crops again. The 4 species of this blend are annual ryegrass, winter rye, crimson clover, and winter peas. Annual ryegrass creates a short dense turflike growth with a dense mat of roots holding and covering the soil, reducing erosion and weed germination. Winter rye adds an enormous amount of carbon to the soil and provides support to the winter peas. Crimson clover adds nitrogen to the soil and produces flowers to feed beneficial insects in the garden. Winter peas also fix nitrogen in the soil while also being edible. The tender growing tips of pea plants are delicious all winter long.
Bok choy is a delicious and nutritious vegetable that is pretty low maintenance to grow in St. Louis, EXCEPT, it tends to quickly bolt once it gets hot. Given St. Louis’ erratic spring weather this tendency can be a huge problem. It’s not unusual for us to hear from gardeners who had their bok choy bolt and stop producing before the plants were even big enough to harvest. So this spring we did a variety trial with the goal of identifying one or more varieties of bok choy that were resistant to bolting and produced well in St. Louis and we are happy to say we found 3 varieties that did exceptionally well. Before we get into that let’s first talk a little about bok choy.
Bok Choy Background
Bok choy is a member of the brassica family. But it is Brassica rapa, not Brassica oleracea (the species that includes cabbage, broccoli, cauliflower, kohlrabi, brussels sprouts, collards, and kale). Like Brassica oleracea though Brassica rapa is a species that was domesticated into many different crops. Brassica rapa includes bok choy but also turnip, tatsoi, broccoli raab, napa cabbage, komatsuna, field mustard, and several other types of less common greens.
Although Brassica rapa is from somewhere in Eurasia, the exact location of its original domestication is debated. However, bok choy specifically is generally accepted to have been developed in the Yangtze River Valley of China. From there it spread throughout East Asia and then to the rest of the world. As its place of origin, and where it is still the most popular, China has the greatest diversity of bok choy varieties and where the bulk of the world’s bok choy is still grown.
When bok choy was developed there were two main types that were developed; green stemmed and white stemmed. Green stemmed varieties are generally speaking more forgiving and adaptable. White stemmed varieties are generally the ones you will see at the store because the brilliant white colored stems look nice and they tend to be more juicy and crunchy.
Here you can see all the bok choy in the trial on May 20th. You can see on the right that one variety has already bolted and another is in the process of bolting.
Our Test
In an attempt to find a variety that would grow well in St. Louis, despite our erratic springs/summers, we identified 7 varieties that were claimed to be the most heat and bolt resistant. The 7 we tried were:
Chun Mei
Chun Yu
Jimao Choi
Mei Qing Choi
Extra Dwarf Pak Choi
Hotau Improved
Joi Choi
One by one extra dwarf pak choi, mei qing choi, hotau improved, and then jimao choi bolted with extra dwarf bolting in mid-May and Jimao bolting by mid-June. Even these varieties that “failed” did quite well considering how most bok choi performs in a St. Louis spring. Hower joi choi, chun mei, and chun yu left the others in the dust.
Joi Choi
A head of joi choi that was harvested mid-June.
Given that white stemmed varieties tend to be more picky about their weather than green stemmed varieties we were shocked when joi choi, a large bok choy with thick succulent white stems, was one of the last to bolt in our test. The other white stemmed varieties in our trial bolted in May. Joi choi bolted over a longer period of time than the others, where all individuals of the same variety bolted within a week. The first one started bolting in the second week of June but we didn’t end up harvesting the bulk of the joi choi until the end of June which is impressively late. By this time those plants had endured many days in the 80’s, 90’s and even a day that reached 100 degrees.
Mature heads of chun yu and chun mei in mid-June
Chun Yu
Chun yu is a green stemmed variety that produces baby sized heads. It never actually bolted but by the first week of July it was starting to elongate and look a bit ragged so we harvested it.
Chun Mei
This is what chun mei looked like in mid-July when we finally harvested them. Although they may not be the prettiest they still tasted great, with no bitterness.
The winner of the trial. Chun mei was almost identical to chun yu in size and look but seemed a bit more bolt resistant than chun yu. Like chun yu it never actually bolted but started elongating and looking ragged in July. Unlike chun yu though this didn’t happen until mid-July! This is incredibly late in the season to harvest bok choi that hasn’t been protected from the heat in some way. By the time we harvested the chun mei those plants had endured 38 days of temperatures in the 80’s, 15 days of temperatures in the 90’s and even a day that reached 100 degrees. Not too shabby for a cool season crop prone to early bolting.
Conclusion
All of the varieties we tried did comparatively well against most bok choy we have grown in the past but if you are looking to grow a large bok choy and/or a white stemmed bok choy, joi choi is a great one to grow. If you want to grow a green stemmed and/or baby bok choy, try the varieties chun yu or chun mei.
We are into tomato season! If you have noticed some of your tomatoes developing a brown or black spot on them it could be blossom end rot. This rot is mostly seen in tomatoes but it can also affect cucumbers, melons, squash, and peppers. Luckily, blossom end rot is not a fungus! Instead, it is a structural deficiency caused by inadequate calcium when the tomato is forming. This structural deficiency may provide an entry point for other diseases but even without a fungus, the bottom will be sunken, water-soaked, and maybe black or brown and leathery. Some varieties are more prone to it than others – elongated and pear-shaped sauce tomatoes are the most susceptible.
In some areas, blossom end rot occurs simply because there is not enough calcium in the soil. This isn’t usually the case in St. Louis because our soil’s parent material is limestone, which is composed primarily of calcium carbonate (CaCO3). So, adding calcium, as you might assume, may not fix the problem.
If a lack of calcium is not the problem it could be too much moisture when the tomato fruit was forming followed by a significant dry period for the tomatoes. This uneven soil moisture makes the abundant calcium in the soil unavailable to the plant. The solution is two-fold.
First, mulch the soil with 2-3 inches of compost or leaf mulch. This evens out and maintains soil moisture as the mercury climbs. It also suppresses weeds and improves soil structure and health.Second, check soil moisture before watering. Insert your finger 2″ deep into the soil. If it is moist, hold off another day or so. If it is dry or nearly dry, water deeply.
Another potential cause is that the plant is growing too vigorously and the plant couldn’t keep up with its calcium uptake. This vigorous growth is caused by excessive nitrogen. If you are fertilizing your tomatoes, make sure that you are using an OMRI-certified fertilizer lower in nitrogen, lower the dose, and/or fertilize it less frequently. However, regular application of healthy compost, crop rotation, and planting cover crops to promote long-term soil health is preferable to regular fertilizing.
In St. Louis, right around now is the time to start planting zucchini and summer squash. These plants love our long summers and produce lots of fruit but lots of gardeners have trouble with pests getting to them.
One of the most common pests that kill squash is the Squash Vine Borer. If you have had problems in the past with your squash plants looking healthy one minute and then wilting and dying out of nowhere then you may have had vine borers. This is a tell-tale sign of them because the borer eats its way up into the base of the squash plant and prevents nutrients and water from being taken up by the roots and reaching the rest of the plant.
There are few options for dealing with vine borers. First, you may want to plant varieties that the vine borers do not find as tasty. If you like zucchini or summer squash, think about trying Tromboncino squash. If you are looking to replace pumpkins or winter squash you can try Seminole Pumpkins. Both of these varieties have little to no pest pressure from vine borers. But if you do not want to grow those varieties you still have some options. The Squash Vine borer starts as cocoons in the ground. In Missouri, the adult moth emerges from the cocoon around late May to June. The moth’s wings are green and it has an orange and black body. It looks similar to some wasps.
Once the moth has emerged it lays eggs at the base of squash plants. About a week after the eggs are laid they hatch the borers that eat their way up into the squash plant. After they’ve had their fill in the squash plant which is about a month to six weeks, they go back underground and stay underground until the next summer.
A bed of summer squash covered with insect netting
The simplest method to prevent squash borers is to cover your squash plants while the adult moths are out. You can cover your plants with a floating row cover or insect netting. This cover can be put on the right when you plant squash and you can leave it on until your squash plants start to flower. You can water through the covers. You can hold up the covers with PVC or small metal rings.
If your squash died last year do not plant squash there again. The vine borers will be in the ground and if you cover the squash plants, you are trapping the vine borer moths under the row cover with your squash!
If you have not covered your squash there are a few other things you can do. To see if you have the borers look at the base of your squash plants. Holes and orange goo at the base are signs that the vine borers are in the squash. You can try and cut them out by cutting an incision lengthwise at the base and then covering it with soil after you pull out the borer. There can, however, be multiple borers in one plant. You can also try to kill the borers while they are inside the stem of the squash plant. You can do this by taking clothespins or something sharp and stab into the side of the base of the plant.
There are other ways to deal with vine borers but we find growing squash they do not like or using a physical barrier as the most effective ways to deal with them.
When you have a garden in St. Louis you have plenty of produce in the summer and fall and usually well into winter through things like squash, sweet potatoes, cold hardy greens, and by ripening green tomatoes inside. With some pretty low tech season extension like low tunnels it’s also easy to overwinter cold hardy greens like collard, kale, spinach, and turnip greens in order to have fresh produce all the way until those bolt, usually in March. Unless you are doing indoor or greenhouse gardening though there is usually a gap from March (after the greens bolt) until well into May where there isn’t much of anything you can harvest from the garden other than maybe some early planted greens or green onions.
Before widespread food distribution networks this period was called the ‘hungry gap.’ Knowing that people want and/or need good fresh produce from their garden all year and not just part of the year we have experimented with different crops over the last couple years to try and find ways to help fill this ‘hungry gap’ in St. Louis gardens. Europe’s climate has a similar ‘hungry gap’ in their growing season and the people of western Europe have spent many centuries trying to fill that ‘hungry gap.’ Those crops for the most part have not been grown here because our winters are more extreme than the parts of Europe where those crops were developed so they couldn’t overwinter here. However, given the heat island effect of growing in a city, our increasingly warm winters, and the accessibility of cheap and effective coverings like row cover and low tunnel plastic that can keep the plants a bit warmer we thought these crops were worth a try.
OUR FIRST WINTER BRASSICA – SPROUTING BROCCOLI
Sprouting broccoli plants in Mid-January
A few years ago we tried growing our first winter brassica, sprouting broccoli, in order to fill the ‘hungry gap’ and it was a big success. We planted it in the fall at the same time we planted our fall broccoli, cabbage, kale, and collards, covered them with a single layer of row cover, and by mid-March there were small broccoli heads forming on the plants, before we had even planted our spring planted broccoli.
Sprouting broccoli florets on March 25th
Although sprouting broccoli produces smaller heads than newer broccoli cultivars they are a nice hearty addition to that early spring garden. They also produce many side shoots and you can keep harvesting from them for several weeks.
After growing sprouting broccoli successfully for several years we decided to investigate if there were other “winter brassicas” that we could trial in order to see if they could successfully survive our winters. We were able to get seed for 3 varieties of winter cabbage and 4 varieties of winter cauliflower and decided to do a variety trial. Although this is the first year we have grown them and we will need to grow them for several more years to verify our results, our initial trial was very successful. We will go through what varieties we tried, how we grew them, the results, and what we would recommend if you want to grow them yourself.
WINTER CABBAGE
When we were looking at winter cabbage varieties we wanted to find the most cold hardy variety of green cabbage, red cabbage, and savoy cabbage. The three varieties we tried are listed below.
Winter King: a standard looking green cabbage
January King: a beautiful purplish green cabbage
Omskirk: a savoyed green cabbage
Winter cabbage is different from sprouting broccoli and winter cauliflower, it’s really just a more cold tolerant cabbage. So like any other fall vegetables they need to be planted early enough to be full grown by the second half of November at the latest. If they are mature by then, due to their cold tolerance they can just hang out in the garden all winter and you can harvest them whenever you need cabbage.
All three of the cabbage varieties survived our winter just fine. They were unprotected for all of the winter except for the week long period in February when temperatures were unusually low. For that week we covered the cabbage with a layer of low tunnel plastic and a layer of row cover. We did this because we wanted to make sure at least some would survive so we would know which was the most cold hardy. Low and behold they all survived with virtually no damage beyond a leaf or two with a little freeze damage on the edge of the leaves, despite the fact that there were several days in a row where the temperature never got above 5 degrees. This would suggest that we didn’t need to cover them as much as we did, or possibly at all over the winter.
It’s important to note at this point that we planted our winter cabbage too late. We didn’t get the seedlings in the ground until mid-September so they did not have heads on them by the time winter started. Since cabbage will bolt by the time spring comes we did not actually get any fully formed cabbage heads. However, the cabbage plants did start forming heads before they bolted, they just didn’t fully mature before they bolted and there were noticeable differences in how they grew that are interesting to note to inform further grow trials.
‘Winter King’ was probably the least successful variety. They were slower growing than the others and several of them started trying to form multiple heads in late winter instead of just one. They also were definitely the smallest plants and heads by the time they bolted and several of the individual plants didn’t make it to spring.
‘January King’ was by far the prettiest cabbage I’ve ever seen and did quite a bit better than ‘Winter King.’ All of the ‘January King’ plants survived the winter. They also started forming heads, which got pretty large, before they bolted.
‘Omskirk’ seemed to be the best of the three varieties. They all survived and had really no leaf damage over the winter. They also started forming heads in the fall and then they kept growing in the spring. Due to this they were the largest plants and had the largest heads of all three of the varieties.
WINTER CAULIFLOWER
Winter cauliflower was definitely the big success story of our trials in the winter of 2020-2021. We were able to get seeds for four varieties. The varieties are listed below.
Prestige
Corella
Chester
Fredor
Like the winter cabbage the winter cauliflower were planted in mid-September and left uncovered until the cold snap in February when they were covered in the same way. ‘Prestige’ didn’t survive the winter but the other three varieties survived. They each had some frost damage on the leaves but recovered just fine. So like the cabbage it seems possible that they didn’t need as much coverings as we provided them during the cold in February.
Mature ‘Corella’ and ‘Fredor’ Cauliflower
‘Corella’, ‘Chester’, and ‘Fredor’ all produced well. ‘Corella’ and ‘Fredor’ both started producing around April 15 and we harvested the last head off of those varieties on April 27th. April 27th was also the first day we harvested heads off of ‘Chester.’
A ‘Chester’ cauliflower head
‘Chester’ produced the most ideal looking cauliflower heads of the three varieties but the weather was much more erratic when the heads of ‘Corella’ and ‘Fredor’ were forming so it’s unclear if the difference was due to varietal differences or weather differences. We will have to grow them again to know that. However, we can say that all three varieties produced heads that were very flavorful and tender.
HOW TO INTEGRATE WINTER BRASSICAS IN YOUR GARDEN
We will continue to experiment with these interesting varieties but if you want to try them yourself in order to be able to harvest more than greens from your garden in the winter and early spring below is what we would recommend.
The most important thing is to make sure you get them planted early enough. Seedlings for the winter cabbage should be planted in the first half of August to assure they have enough time to mature before winter. Sprouting broccoli and winter cauliflower should be planted as seedling between the beginning of August and the third week of September to make sure they are established before winter sets in.
We also recommend to be prepared to cover them. As we discussed above covering isn’t necessary unless the temperature become very cold but what exact temperature they need protection from is unclear. Until we have a more clear picture of how hardy these plants are we recommend covering if the temperatures are predicted to get down into the mid teens or lower, although again, as discussed above, that might not be necessary.
A newly emerging cauliflower head on April 7th
If you are wanting to increase the food produced in your garden throughout the winter and early spring we recommend growing a combination of winter cabbage, sprouting broccoli, and winter cauliflower. You should be able to harvest the winter cabbage as needed all winter until about Mid-March when it starts to bolt. Conveniently, it was around this same time on March 15th that we got our first harvest of sprouting broccoli this year. The sprouting broccoli continued to produce until April 7th, when we harvested the last ones and ripped out the rest of the bolted plants. It was on this same day that we saw our first cauliflower heads forming and then a week later on April 15th we harvested our first cauliflower from the ‘Corella’ and ‘Fredor’ varieties. Then on April 27th we harvest the last of the ‘Corella’ and ‘Fredor’ heads and the first of the Chester cauliflower heads.
So if you plant winter cabbage, sprouting broccoli, and ‘Corella’ and/or ‘Fredor’ cauliflower, and ‘Chester’ cauliflower you could potentially be harvesting nice hearty brassicas fresh from your garden from early December all the way through early May!
So we will grow these varieties this winter, along with a few more winter cauliflower varieties we were able to get seed for this spring, and continue to trial them going into the future. We will also of course continue to share our findings with all of you. If you grow them we would also love to hear your results to add information to our trials.
In 2020 we did two different variety trials at our Demonstration Garden. A variety trial is simply growing two or more varieties of the same crop in the same place to see how well they do in comparison to each other. We did a variety trial for sweet potatoes to see if there are varieties that will grow just as well or hopefully better than the sweet potato we have been growing for a long time, ‘Beauregard’. We also did a variety trial of heat tolerant fast maturing cauliflower in an attempt to find a cauliflower variety that was viable in St. Louis. We were lucky enough to get promising results from both trials so if you are interested in growing sweet potatoes or cauliflower this year check out what we found.
SWEET POTATOES
If you have ever grown sweet potatoes in St. Louis what you have almost certainly grown is the classic orange variety called ‘Beauregard’. Most other varieties are better adapted to more southern locations with longer growing seasons. We have been growing ‘Beauregard’ for many years and have always had good results. They tend to be reliable producers and high yielders but we wanted to see if there were other sweet potatoes that would do well. In particular we wanted to see if there were sweet potatoes that were colors other than orange that would grow well here and produce comparable yields to ‘Beauregard’.
Although orange is the classic color that most people associate with sweet potatoes and an increasing number of people are aware of purple sweet potatoes which are popular in parts of Japan, sweet potatoes come in a whole rainbow of colors. In addition to orange and purple there are also white, yellow, pink, and red colored sweet potatoes. For this variety trial we searched out sweet potatoes that were as many different colors as could be found while also having days to maturity equivalent to ‘Beauregard’.
In total we identified and planted 8 varieties of sweet potatoes in 2020 which are profiled below.
‘All Purple’: purple skin and flesh
‘Carolina Ruby’: red skin and orange flesh
‘Red Japanese’: red-purple skin and white flesh
‘O’Henry’: yellow-cream skin and white flesh
‘Hayman’: cream skin and yellow flesh
‘White Yam’: brown-yellow skin and white flesh
‘Bonita’: light pink skin and light yellow flesh
‘Beauregard’: orange skin and orange flesh
The harvested ‘O’Henry’ sweet potatoes
Although they were all listed as having comparable days to maturity and they were all planted in the same large raised bed, and watered and weeded the same amount there were definite differences in yield and quality of the sweet potatoes produced. The variety ‘All Purple’ was the biggest disappointment. It produced two decent sized sweet potatoes and a bunch of finger sized potatoes and that was it. The varieties ‘Bonita’ and ‘White Yam’ produced ok but noticeably less than ‘Beauregard’. The varieties ‘O’Henry’ and ‘Red Japanese’ did about as well as ‘Beauregard’. The real stand outs in our trials however, were the white variety ‘Hayman’ and the red skin and orange fleshed ‘Carolina Ruby’. These two varieties yielded quite a bit more than even ‘Beauregard’ did in our trials.
‘Carolina Ruby’ in the foreground and ‘Hayman’ in the background being harvested by two our long term volunteers
‘Carolina Ruby’ had a taste and texture similar to the standard ‘Beauregard’ sweet potato so would be a good one to try if you want to branch out but still love the classic sweet potato taste. ‘Hayman’ as well as all the other white sweet potatoes though were quite different. White sweet potatoes have a more neutral flavor and texture and are more akin to a potato. They are more adaptable in recipes and more easily used as a staple food. They are very popular in many areas of Africa due to this. For 2021 we will be growing ‘Hayman’ and ‘Carolina Ruby’ again to verify the results from 2020 in addition to a few other varieties to continue our experiments.
CAULIFLOWER
If you have ever tried to grow cauliflower in St. Louis you know that it’s a very hit or miss crop in our climate. If you are lucky to grow it in a year that we have an unusually long spring you might get great cauliflower, but more often than not cauliflower doesn’t have enough time to grow and produce a head before it gets too hot. So usually they will produce bitter tough spicy bolted heads which are a big disappointment after waiting all spring for some delicious cauliflower. We have tried cauliflower many times and this has almost always been the case, but who doesn’t love cauliflower? So in 2020 we researched and sought out as many varieties as we could find that were supposed to be heat tolerant and also had the shortest days to maturity. We hoped this would mean they would be likely to mature before the heat of summer but even if it got hot while they were still forming a head that they would be able to pull through that heat without bolting for a while.
Ultimately we were able to identify and find seed for 6 varieties that met our criteria. Those varieties are listed below.
‘Multi-Head’: conventional cauliflower with one main head and smaller heads around it
‘White Corona’: standard cauliflower
‘White Express’: standard cauliflower
‘Minuteman’: standard cauliflower
‘Fioretta 60’: loose headed cauliflower with white buds and green stems
‘Song TJS-65’: loose headed cauliflower with white buds and green stems
This picture was taken May 18th showing those that bolted and the variety that didn’t
Cauliflower likes consistent mild temperatures so 2020 was a great year to trial these varieties for heat tolerance and bolt resistance. There was a hard freeze on March 7th and by March 27th it was 80 degrees and then hit 90 degrees on April 8th and then we had another freeze 10 days later on the 18th. Despite their supposed fast maturity and heat tolerance, by the end of May 4 of the 6 varieties had bolted before producing any edible cauliflower. At that point in time we had had 1 day of temperatures in the 90’s and 11 days of temperatures in the 80’s.
The loose heads of Song TJS-65 harvested on June 10th
On June 10th we harvested ‘Song TJS-65’ cauliflower at which point the plant had endured 17 days of temperatures in the 80’s and 7 days of temperatures in the 90’s. The cauliflower was delicious but it was definitely unique and not what most people expect from cauliflower. It was almost like a whole different vegetable so would be a great addition to the garden but might not satisfy your desire for cauliflower.
The first head of ‘Minuteman’ ready for harvest on June 18th
The cauliflower that lasted the longest was ‘Minuteman’. It produced a classic cauliflower head that most would expect when growing cauliflower. We harvested the first head of June 18th at which point the plants had endured 24 days of temperatures in the 80’s and 9 days of temperatures in the 90’s. We then left a few heads of ‘Minuteman’ cauliflower growing to see how long they would stay good and by the beginning of July they started to get a little spicy and a little bitter. At this point the cauliflower plants had endured 29 days of temperatures in the 80’s and 16 day in the 90’s! It’s also significant to mention that ‘Minuteman’ produced good tasting heads through all that heat without us tying the leaves over the head, they were fully exposed to the sun. ‘Minuteman’ blew away all other cauliflower and it will definitely be a variety we grow again.
If you have done any trials of cauliflower, sweet potatoes, or really any other vegetable in St. Louis or a similar climate and had a variety that really impressed you let us know! We area always looking for new varieties.
If you want to try something new and different this year and still get a fair amount of food than water chestnuts are worth a try.
There are actually two different, unrelated crops that are commonly known as water chestnuts; Eleocharis dulcis and Trapa natans. Trapa natans is a floating aquatic plant that can grow in water up to 15 feet deep whose seeds are eaten whereas Eleocharis dulcis is an aquatic plant that likes to grow in shallow standing water of around 4” deep whose tuber like corms are eaten. It is Eleocharis dulcis that we did a grow trial of at the demonstration garden in 2020 and from here on out that is the species we will be referring to when we say water chestnut.
Side benefit of growing water chestnuts is building habitat. We had quite a few tadpoles living in our water chestnut “ponds.”
Although water chestnut is a perennial in hardiness zone 9 and higher where winters only go down into the 20’s at their lowest, in St. Louis it’s grown as an annual. To get a good harvest when growing it as an annual it needs about a 7 month growing season. It’s an aquatic plant that likes to be grown in standing water. Different aquatic plants prefer different water depths but it is generally accepted that about 4” of standing water is optimal for water chestnut. Also like pretty much all crops they do best when they have full sun.
HOW TO GROW WATER CHESTNUTS
FINDING PLANTS AND STARTING SEEDLING
The first thing you need to do to grow water chestnuts is to find water chestnuts to plant. Water chestnut plants are grown by planting fresh water chestnuts, similarly to how garlic or potatoes are grown. The tricky part is that although water chestnuts can be found in just about any grocery store in a can, they are much harder to find fresh, which is what you need. Your best bet is to look at an international grocery store or to find some for sale from a grower online.
A small water chestnut ready for planting
The water chestnuts can be quite small for planting, in fact the ones we got were very small as you can see in the picture. Once we have the water chestnut starts we planted them into individual pots in potting mix and put all of the pots into a tray to hold water. Then we put them under our grow lights just like all of our other seedlings. When they are little they need plenty of water but don’t need to be in standing water so we just watered them until water came out of the bottom of the pots and stated going into the tray beneath them.
At this point you just treat them like your warm season vegetable seedlings, keeping them inside with plenty of light and water until the temperatures warm up.
GETTING A PLANTING AREA READY FOR THEM
Based on our trials this year any container that can hold water and that you can put in full sun will work. The kiddie pools worked well for us and they are cheap and easy to get. They also give you a pretty large growing area for how much soil you need and for the cost of the container.
Once you have a container picked out you need to fill it with soil. The kiddie pools we had we put 5-6” of soil in the kiddie pool. A good garden mix is best. Since it’s essentially a pot the plants only have the nutrients that are in the soil you put in there, there roots can’t wander so you don’t want to put just topsoil. Nice rich soil is best. We added some potting mix to ours because we had it and it worked but all the perlite (the little white beads that look like Styrofoam) floated to the top.
PLANTING AND GROWING THE WATER CHESTNUTS
Once your container is prepped it’s time to plant. They are warm season plants so it is best to wait to plant them outside at the same time you would plant your tomatoes, beans, and squash. They spread quite a bit over the growing season so you also don’t need many plants. We only planted 6 little water chestnut plants in each kiddie pool and they were full by the end of the year as you can see in the pictures below.
Left: water chestnut containers on July 22nd. Right: water chestnut containers on August 21st
Once they are planted just water the container until a minimum of one inch of water is standing on top of the entire surface. Then the rest of the growing season all you need to do is add more water anytime there isn’t standing water on the surface. If you keep them watered enough so there is always standing water there will be virtually no weeds and you won’t need to weed the container.
HARVEST
A hole dug in the side of the water chestnut container allowing you to bale the water out for harvest
In the fall you will start noticing the tips of the green tops will start turning straw colored and drying out. Over several weeks they will continue to turn from green to straw colored moving from the top down. This is normal and a good sign. It means that as winter is coming the plant is recognizing it and putting the energy that’s in the green tops that are inedible down into the water chestnuts below ground that you want to eat. Once the tops couple of inches are straw colored you no longer need to keep it flooded.
Once the tops are mostly straw colored, or if a cold period down into the mid to low 20’s or lower is coming it’s time to harvest.
The first step is to drain off the water. The easiest way to do this is to dig a hole in the container all the way down to the bottom on the side big enough for you to reach down to the bottom with a cup or other thing that will hold water. You can see an example in the picture below. Then fill up the cup with the water and dump it out. Continue to do this until the water is all drained from the container.
Then all you need to do is work up the soil with a trowel or your hands. Since the soil is so wet it’s generally easy to just work through the soil with your hands and pull out the water chestnuts as you find them.
Water chestnuts grow on the ends of roots. The soil is usually soft enough that pulling the whole plant out will yield many of the water chestnuts.
STORAGE
These freshly harvested water chestnuts are ready to be put in a plastic bag in the fridge
As with most root crops it’s best to not wash the water chestnuts. After harvesting they are generally caked in mud and this is actually good. It will help keep them wet and protected from drying out. Store them in a loosely closed plastic bag in your refrigerator, ideally in the crisper drawer. As of this writing we have had them stored this way for over two months and they are still nice and crisp.
PREPARATION
The only preparation needed is to wash them and peel them. I found the best way to wash them is to take a handful and rub them all together in your hand vigorously under running water and the dirt comes off very quickly. Then peel them with a knife or vegetable peeler.
After that use them however you like. They are edible raw but are also great in all sorts of dishes to add a nice fresh crunch to almost any meal.
OUR 2020 TESTS TO DETERMINE THE BEST STRATEGIES TO GROW
Since not everyone has full sun and because setting up a growing area that will hold standing water might not be easy for everyone we grew our water chestnuts in 4 different beds with different situations to see what was most important to get a good yield of large water chestnuts. The size of the water chestnuts is particularly important because they have to be peeled so even if you get a high yield if they are the size of a large bean it’s not very feasible to peel them vs. ones that are the size of a large walnut are much easier to peel. We used four different beds to compare the impact of soil depth, sun, and water level on yield and the size of water chestnuts. The four beds were as follows
Bed 1: Full sun 8” deep kiddie pool with several inches of standing water all year
Bed 2: Full sun 8” deep kiddie pool with a hole in it that was watered heavily but not flooded
Bed 3: Partial sun 8” deep kiddie pool with several inches of standing water all year
Bed 4: Full sun 24” deep rice bed with a hole in it that was watered heavily but not flooded
Bed 1 is what is generally recommended by others. Bed 2 is to see if the water chestnuts could be grown in heavily watered but not flooded conditions similarly to how some rice varieties can be grown with minimal yield impacts. Bed 3 was to see how much impact level of sun has on yield and water chestnut size. Bed 4 was to see if a deeper bed would result in higher yields by comparing it to Bed 2 as a simulation of growing it in ground.
TEST RESULTS
Bed 1 on the right, Bed 2 on the left on August 21st. Although they both filled the bed by the end of November it was obvious when this picture was taken that the plants in bed 1 were much happier
What we found from the tests were that the most vital factor to both yield and size of water chestnuts is sun. Bed 3 had by far the lowest yield and smallest size water chestnuts. Most of the water chestnuts in bed 4 were two small to feasibly peel. Water level was the next most important with Bed 2 and Bed 4 yielding more than bed 4 but about half the yield as bed 1 per square foot. The size of the water chestnuts in the unflooded beds were nice and big still. Soil depth seemed to have little to no effect on yield or size of water chestnut. The size of the water chestnuts in Bed 2 and Bed 4 were almost identical and the yields were also very similar. The only real difference that was noticed was that the water chestnuts in Bed 4 were more spread out whereas those in Bed 2 were almost all growing right on the bottom of the kiddie pool so harvest was much faster in Bed 2.
Left: water chestnuts from unflooded Bed 2. Right: water chestnuts from flooded Bed 1
What all of this seems to suggest is that shallow pots like kiddie pools will work fine as long as you grow them in full sun and to maximize yields you really want a container that will allow standing water.
2021 TEST RESULTS
After our success in 2020 we grew water chestnuts again in 2021. We confirmed our results from last year harvesting a pound per square foot in the containers that were in full sun and flooded and slightly less in those that were heavily watered but in containers that had a slow leak. We also confirmed that those that were in full sun produced large water chestnuts. In fact this year the chestnuts were on average much larger than last year now that we know what we are doing, making them much easier to peel.
In total we harvested a little over 29 pounds of large water chestnuts from 1 raised bed lined with plastic and 2 kiddie pools.
After seeing that the water chestnuts grew fine in the kiddie pool that was watered heavily, but had a leak so did not have standing water, we decided the next step would be to see if they could grow in a normal raised bed that was watered heavily. Unfortunately they did not survive, let alone produce a harvestable yield.
We also tested to see if the container size affected the yield or water chestnut size and received promising results. Whereas last year we planted in large kiddie pools about 5′ in diameter, this year we planted in both a 5′ diameter one from last year and a 3′ diameter one to see if the smaller size would have a negative impact on the yields. What we found was although the water chestnuts were slightly smaller than in the larger kiddie pool they were still large enough to peel and the total yield was comparable per square foot.
So our results from last year stand that full sun is critical for large water chestnuts and yield and that the more water they get the higher the yield. We also confirmed last years results that depth of container doesn’t seem vital, with the kiddie pools yielding equivalent to the raised bed per square foot. Finally, we found this year that container size, at least down to a 3′ diameter kiddie pool (7 square feet), doesn’t seem to negatively impact harvestable yield.
