Gardening: It’s planting time for cool season crops

Last week I discussed planting onions. That brought questions from readers about the timetable for planting other vegetables.

Most vegetables that you seed into the garden germinate when the soil gets to the right temperature. A month ago I measured the temperature in my garden at 45 degrees. Saturday it was up to 50. Not much of a shift but enough that more cool season crops are able to germinate.

Now is the perfect time to seed cool season crops like onions, spinach, lettuce, beets, peas, Asian greens, carrots, potatoes, kale, broccoli and cabbage directly into the garden. The seeds will take some time to germinate so be patient. Cabbage, Brussels sprouts, broccoli and cauliflower can also be purchased as transplants if you are in a hurry. These small started plants transplant easily and will save you several weeks at harvest time.

Lettuce and carrots can be tricky to plant because the seeds are very small and they are planted right at the soil surface. Try mixing the seed with a little sand and then scattering the seed-sand mix evenly over a wide bed and mixing them into the very top of the soil. Water them in gently and cover them with a sheet of cardboard weighted down to keep it from blowing away. Check every few days until you see the plants emerge then remove the cardboard. The cardboard helps keep weeds from germinating and overtaking the slower growing lettuce and carrots.

After gardening here for nearly 40 years, I have come to expect a frost sometime around Mother’s Day. As a result, in my colder-than-average Spokane Valley garden, I don’t even think about planting frost sensitive plants until after the middle of May and I often wait until Memorial Day to direct seed beans, corn, cucumbers, zucchini and summer squash. While the seed tolerates cool soil, the emerging leaves will wilt quickly when the temperatures get close to freezing. Corn should be planted as seed rather than buying plants for two reasons. First, you have to buy lots of them to be worth the effort and secondly, corn roots are very sensitive to the shock of being transplanted into the garden.

Tomatoes, peppers, eggplant, melons and winter squash are better planted out as transplants around Memorial Day into the first week of June. Our growing season is just too short to expect tomatoes, eggplant and peppers to sprout and then have enough time to grow and be ready to flower when the night temperatures are above 55 degrees. It is too late in the season now to seed them indoors and expect them to be strong enough to plant out when it warms up. On the other hand, you can still seed melons and winter squash in porous coir (coconut fiber) pots under lights indoors and plant them out, pot and all, around June 1. Like corn, melons don’t like having their roots disturbed by transplanting.