WONDER WHAT TO SOW WHEN to get homegrown transplants ready for the vegetable garden? I’ve gathered links to some foolproof online seed-starting calculators and charts, and also summarized my very simple “lumping” method, where I group all my seeds into three groups rather than try to remember every last detail of what happens when. The scoop:
charts and calculators
- New! A Way to Garden’s own vegetable, flower and herb-seed calculator
- All Things Plants’ Calculator (by zip)
- Maine Organic Farmers and Gardeners Association Seed Chart (Note: It counts back from a frost-free date around the end of May.)
- The Old Farmer’s Almanac Seed Calculator
- Johnny’s Selected Seeds’ Calculator
my ‘lumping’ method of when to sow
BY LUMPING THE CROPS I SOW INDOORS in spring into three simple groups with similar time needs, I streamline my seed-starting. You’ll need to memorize only one fact to use my “lumped-together” countdown formula, and that’s your local date of average final frost (mine isn’t until close to June).
The brassicas, like broccoli, Brussels sprouts, cabbage, cauliflower and kohlrabi, all have the same requirements: a month to six weeks indoors under lights before they go outside, which is safe about a month before final frost. This group therefore gets its start between March 15 and April 1 in my household. (Note with Brussels sprouts: many resources say sow them later, like May 1 or so, so they stand well into frost, when they achieve their best flavor. Today there are varieties requiring as few as 82ish days to maturity and as many as 100-plus, so take into consideration which you’re growing when you plan when to sow.)
Tomatoes, peppers and eggplants make up my second group, each getting six to eight weeks under lights before transplanting, when all frost danger is past. Early to mid-April is my target sowing date, therefore—a friend nearby makes it even simpler, and says to sow your tomatoes at tax time.
The last group: the big-seeded sorts like pumpkins, squash, melons and cucumbers, which only need a couple of weeks indoors (or if you think you can outsmart the chipmunks, who usually take the seeds at my place, just direct sow around your frost date). Inside, I start these in mid-May or so.
Speaking of what else to sow outdoors…everyone differs on that. Things I prefer to direct sow because it’s so easy include salad greens (lettuce, arugula and such); peas (as soon as the soil can be worked, about mid-March here); and spinach (either late fall for an extra-early crop, or very early spring); chard; broccoli raab; beets and other root crops; kales and collards; dill, and beans.
With the greens, there’s a tradeoff some years to direct-sowing, especially for me with the leafy brassicas (the kale and collards), which can coincide sometimes with an upsurge in flea beetles, who eat tiny holes in things (they love arugula, too). Sometimes starting the plants indoors can outsmart the flea beetles, but growing them under a floating row cover will help, too. I never start peas or beans indoors; the rest I sometimes do, again, to cope with pests.
I often buy my onions as plants, since they take 8-10 weeks indoors, but you can sow indoors, too (I would have done so in February for an April set-out).
Basil and parsley, two other staples, fit into the system, parsley with the early stuff, basil with the later.
Experts who disagree and say eggplants actually need a week or two longer indoors (like eight) than tomatoes and go outdoors a week later, for instance. They’re right, in the best of worlds. But lumping is simpler, and since no two weather years are alike—particularly no two springs—I expect there’s a kind of built-in balancing act going on outdoors, anyhow.
How to sow indoors, in a simple slideshow.