Baby lettuce growing in a cold frame.
If you just can’t wait to get to work in the garden this spring, here are a few secrets for getting a successful head start.
It’s All About Temperature
Air and soil temperature are the critical elements when planting a spring garden. For example:
- Cool-season vegetables need daytime temps in the 60s F and nights in the 40s F with an occasional light frost.
- Warm-season vegetables need daytime temps in the 70s-80s F with nights above 50° F, and they don’t tolerate frost.
- Planting seeds depends more on soil temperature than air temperature. If the soil can be warmed enough for the seeds to germinate, the growing plants may tolerate cooler air temps.
To get a head start in the garden, you’ll need to understand the temperature requirements of your plants, as well as the average spring planting time for your region. Armed with this information and a good thermometer, you can try some of these tips to help Mother Nature warm things up more quickly.
Containers are easy to bring indoors in cold weather.
Outdoor Early Planting Tips
Here are some tips to take advantage of the sunny days in early spring:
- Build a Cold Frame: A cold frame is a simple, low wooden frame with a glass or clear plastic top. It’s placed over seedlings in the garden or over a raised bed to give protection from those last frosty nights in early spring. Sort of like a mini-greenhouse, a cold frame keeps the air and soil inside about 5-10 degrees warmer than the surrounding garden to give you about a month head start on spring.
- Use Containers: Plant early veggies and flowers in containers that can be moved indoors at night and on chilly days. Try this tomato wagon for an easy moveable garden.
- Warm the Soil: Use black plastic, row covers, or solar plant cones to warm up your garden soil and make spring come early to your garden! Plastic helps hold in the sun’s heat, and you’ll get the added bonus of killing some of the weeds and pests under the plastic. Plan on a month of preheating for about a month’s head start. After preheating, you can remove the plastic or simply cut slits for your plants, leaving the plastic as mulch. The warmer soil will help seeds germinate outdoors, but make sure the nighttime air temperatures are above freezing before planting summer veggies.
- Add a Hotbed: You can purchase heating elements to turn your cold frame into a hotbed, or use the traditional manure-heated hotbed technique. A heating element allows you to have more control of the soil and air temperatures, allowing for seed planting and a head start on summer veggies like tomatoes and squash.