Veggies need right soil conditions to sprout
Helen Chesnut
QI would like to have the earliest possible garden this year and am wondering how early I can seed some of the first cool season vegetables in the open garden. I’m thinking mainly of peas and the root crop bed of carrots, parsnips and beets. How can I determine when to sow the seeds?
A: These are the vegetables I usually sow first, beginning with the peas and then the roots. I, too, was hoping for an early start this year, especially in view of the harsh, long winter last year, when the season was delayed by three or four weeks. We’ll have to wait and see whether the recent cold snap will give way to a warm March. I never seed into cold, wet soil. My hopes for a late February pea sowing have evaporated.
The timing for planting seeds depends on soil temperature and
moisture content. Wet soils stay cold longer and working heavy, clay-type soils while they are wet only further compacts them.
Well-drained, open-textured, sandy soils offer the best prospects for the earliest possible sowings. A good
investment and a sure indicator of a soil’s warmth is a soil thermometer.
Soil temperatures for good germination of most root vegetable seeds begin in the 7-10 C range and go to 29 C. Lettuce will germinate at 5 C, while the ideal soil temperature is
24 C. My preference is to seed lettuce indoors starting in late winter for nice-sized transplants to set out into the garden as soon as the soil has lost its winter chill. Beans, a warm-season vegetable (except for broad beans, a cold, hardy type),
need a minimum soil temperature of 18 C, while 27 C is ideal.
To hasten the advent of ideal germination temperatures, some gardeners pre-warm the soil with clear plastic and place a portable cold frame or row cover over the seeded area.