Every winter is a little different, so I use a soil thermometer to keep an eye on the temperature of the soil and plant accordingly.  The thermometer pictured here is actually a meat thermometer, bought for less than $10, but it works just as well as the more expensive soil thermometers you'll find in gardening stores.

To check the soil temperature, get up early before the sun has hit the ground and insert the thermometer into the ground.  Wait a few minutes, then take a reading.  If you have garden areas that are more sunny than others, you'll want to test the soil temperature at several places–I usually find that our soil is two to five degrees colder in the shade of our hillside compared to in the sunnier parts of the garden.

The table below lists the germination temperatures for common spring crops.

Vegetable	Minimum temp. (degrees F)	Optimum temp. (degrees F)
Beets	40	50-85
Broccoli	40	45-85
Brussels sprouts	40	45-85
Cabbage	40	45-95
Carrots	40	45-85
Cauliflower	40	45-85
Collards	45	70-75
Leeks	40	70-75
Lettuce	35	40-80
Onions	35	50-95
Parsley	40	50-85
Peas	40	40-75
Potatoes	45	60-70
Radishes	40	45-90
Spinach	35	45-75
Swiss chard	40	50-85
Turnips	40	60-105

In most cases, you can get away with planting once the soil has reached the minimum germination temperature, but don't plant your seeds if a cold spell is going to set in within a couple of days.  You should also be aware that some vegetables will give you spotty germination until the ground was warmed up closer to the optimum temperature --- you might want to double your seeding rate to ensure a good stand if planting near the minimum.  Once a seed has sprouted, it's less sensitive to cold soil, so expediting germination by soaking your seeds overnight before planting can also help.

To plant earlier than cold soil will allow, many gardeners are tempted to start seedlings indoors.  However, unless you have grow lights or a heated greenhouse, I recommend that beginners stick to growing their plants entirely in the earth for the first year.  A quick hoop might be enough to let you plant a couple of weeks earlier than you otherwise could have, then you can transfer the same protection to a new bed in April to jumpstart your summer garden.

This week's lunchtime series is excerpted from Weekend Homesteader: March.  I saved some of my favorite projects for last, so I hope you'll splurge 99 cents to read about growing edible mushrooms, composting, and attracting native pollinators.  And, of course, the ebook has the full spring planting chapter in case you just can't wait to read each installment at noon this week.

This post is part of our Spring Planting lunchtime series.  Read all of the entries: Spring garden Preheating soil for the spring garden Vegetables for early spring When to plant spring crops How to plant a no-till garden

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About us: Anna Hess and Mark Hamilton spent over a decade living self-sufficiently in the mountains of Virginia before moving north to start over from scratch in the foothills of Ohio. They've experimented with permaculture, no-till gardening, trailersteading, home-based microbusinesses and much more, writing about their adventures in both blogs and books.



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