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
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’ 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
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.
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 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.