The universe unfolded as it should this week, as my Mom got her peas planted on her traditional date, the last day of February. Failure to adhere to this ritual might not knock the planet off its axis, but it would be earth-shaking in my parents’ household none the less.
Planting peas in February is usually a prelude to a March snowfall, but time will tell. In any event, it is time to think about planting the early season vegetable crops, and it’s a good time to buy a soil thermometer if you want to be sure that the soil is warm enough to germinate those vegetable seeds. It doesn’t matter where you live; soil temperature is the best indicator of when to plant.
Generally, a soil temperature of 5 deg. Celsius is required for crops such as peas, lettuce, kale, parsnips, radish, radicchio, and spinach. Push the probe of the thermometer two inches into the soil for these cool season vegetables. Take the temperature at the same location, and at the same time of day, and then average them for most accurate results.
When temperatures increase to 10 deg. Celsius you can plant leeks, onions, Swiss chard and turnips. Soil temperatures need to approach about 15 deg. Celsius before beans, beets, broccoli, Brussel sprouts, cabbage, carrots and cauliflower can be safely planted. But be warned, bean seeds will not germinate if there is any frost after planting, and you may have to plant again.
Temperatures will have to be up around 20 deg. Celsius before you can put in transplants of warm season crops like tomatoes, eggplants, peppers, cucumbers, squash, corn and melons. We’re certainly several weeks before that happens, but it is time to plant seeds of tomatoes, eggplants and peppers in order to have them ready to set out by mid-May. For temperature readings for these crops push the probe four inches into the soil.
Gardeners are very adept at “cheating” a bit to get an earlier start in the vegetable patch. Plastic mulch, cold frames, floating row covers and hot caps are some of the more popular methods for warming up the soil enough to get seeds in, and you can turn the heat up quite substantially with the above, as well as provide a few degrees of frost protection for germinated seeds and transplants.
Just like crossing the street or getting out of bed in the morning, there is risk involved in being the first to have the vegetable garden seeded. Germination and growth of seedlings in the garden doesn’t guarantee their survival if we should be hit with a hard frost. It only ensures another trip to the garden centre for more seeds and/or transplants. But, it’s a risk worth taking to enjoy fresh vegetables before any one else.