Gardeners often get an urgent sense about getting things moving as late March approaches, but that rush can backfire in Zone 6, where ground remains unforgiving. You see the sun and suddeny it’s time to get planting, but who wants frost-killed tomatoes, or pea pods all stringy?
The chart above help distinguish between cool-season crops and those that prefer warmth to prevent any mistakes. Why? The calendar date isn’t everything; so-called heat storage (think: soil) plus soil temperature are what makes things happen.
Plan Your Garden by Soil Temperature
Tomatoes need heat? They don’t like hot weather either. Some cool-season crop like spinach and peas will tolerate chilly temperatures. You can sow them as early as several weeks before the final frost, even if ground is still cold. So, get those babies going with a headstart. Spinach and peas are tough and can handle a chill; peas can be sown roughly six weeks before your last frost date. Many of us sit around waiting for it to be summery outside before we try again, but spinach and peas really like the early spring weather when things is mellow and still damp. By mid-May here, you’ve probably already blown the opportunity on peas.
But other tender plants, eggplants, peppers, tomatoes, are another story. They requires warmth. Get them going inside first. The visual guide remind us to start them indoors and set them out weeks earlier, like onions with their 10-week headstart inside.
Why? Because those plants has to create an extensive root system to hold up all that eventual fruit, and you don’t want to plant a tomato seedling into the earth come April when air has warmed nicely, it will just sit there shivering while it tries to do its thing. That’s what timing’s for.
The garden depends on soil temperature, which means frost is gone even though ground is still chilly where things grow. Corn and beans need soil that is around sixty degrees Fahrenheit… If you plant them earlier, the seeds will rot. Even warmer is required for melons (chart), with about seventy degrees being best. Don’t guess. Don’t check the porch thermometer or any other kind, because you want to know what is happening in the soil itself. A simple soil thermometer remove all the guesswork.
When dirt is cool, the roots are cool, and the plants shut down. In Zone 6, where I garden, it’s somewhere around a hundred sixty-five days from spring to fall, with the hottest part in the middle, and cool shoulders on either end. That means you’d better get busy, and not just by planting and hoping something happens. You need to plan your work and schedule your planting because there are only perhaps six weeks in September or October for things to really cook during a cool fall finishing up; fourteen in high summer for things that love it hot; and eight in Mayish for the cool springtime crowd.
Plant another round of fall-harvest brassicas such as broccoli in July…and miss that July timing, and forget all about fall. If there’s one mistake most of us make, it’s with the soil; we can count on sky more than we can count on the ground. But the ground has all the answers, and once you’re seeing that frost date range of mid-April to early May, then think of it less like a law then a guideline, and that means look to the ground, feel around, and get those onions going early but keep those peppers in check awhile longer.
Patience, not speed, will be rewarded by the garden. And that’s where planning comes in: It sounds restrictive, but it’s really freeing, since it eliminates the guessing game. No more hovering over your garden and wondering what’s wrong with everything. You’ll know when to sow those peas and when to wait until soil warms before sowing that corn.
Don’t rush into it, and then trust that the seasons will provide the rest, once you get out of their way and let them tell you what to do based off the soil.