March is the month of spring gardening! This is the month to plant all of your cool season vegetables. Starting in mid-March you are safe to plant root crops, greens, and brassicas. This is the time to plant carrots, beets, turnips, radishes, spinach, lettuce, collards, kale, chard, mustard greens, arugula, cauliflower, broccoli, cabbage, kohlrabi, bok choy, potatoes, and peas.
Mid-March is the time to plant these cool season crops as either seeds or seedlings depending on what you have. If you want a headstart you should purchase seedlings if you didn’t grow your own. Planting seedlings can give you the equivalent of a few weeks head start over planting seeds of the same crop directly in mid-March. This is particularly true for brassicas, lettuce, and onions. Seedlings of peas, root crops, and greens like spinach and arugula give little benefit. If you would like to plant as soon as possible you can use season extension techniques. Putting a low tunnel with row cover or perforated plastic on it or a cold frame over the bed will protect plants enough for them to be planted this week.
If you wish to grow potatoes, mid-March is when you want to get them planted. Potatoes are grown differently than other spring crops. You plant what’s called a seed potato, which is a potato that has been tested to make sure it’s disease free. You can either plant the whole potato or cut it into pieces, with each piece having at least 2 eyes on it.
March is also a critical time if you want to grow bulb onions. Onions should be planted as soon as possible. Again this is usually mid-March, but with season extension techniques it can be early March. Daylength is what triggers onions to start forming a bulb. The longer the plant is growing before that day length is reached the more energy the plant has and thus the larger the onion bulb will be. Since daylight hours are increasing this time of year, the later you wait to plant your onions the smaller the bulbs will be regardless of weather, water, or plant care than if it was planted earlier.