If you want to get your vegetable garden or lawn off to a fast start, you need to know if your soil temperature is warm enough.
→ Find Your Soil Temperature Map Here
Click on the map link to find your soil temperature by zip code. Use this map as a guide for planting your garden, applying crabgrass preventer, fertilizer, weed and feed and grass seed. Soil temperature, not air temperature is the trigger for seed germination.
Crabgrass preventer needs to be applied when soil temperature is about 55 degrees for 5 consecutive days.
Most grass seed will germinate around 55 degrees.
For Hardy and Semi Hardy Vegetables about 50 degrees: broccoli, cabbage, beets, carrots, cauliflower kohlrabi, onions, lettuce, peas, radish, turnips.
Soil Temperatures For Tender Vegetables about 60 degrees: beans, celery, corn, eggplant, tomatoes, cucumbers, spinach, pumpkin and squash.
What is Soil Temperature?
Soil temperature is simply the measurement of the warmth in the ground. Ideal soil temperatures for planting most plants are usually between 65 to 75 degrees Fahrenheit. For each type of seed which may be grass, beans,pumpkins, carrots, etc, there is a range of temperatures at which that particular type of seed will germinate.
One of the biggest mistakes people make is planting too early. We get excited when it’s sunny for a few day and start putting plants and seeds in the ground. But the seeds are not ready to germinate and plant roots will rot.
To find your local soil temperature at greencastonline.com:
- Enter your city, state or zip code and click green search button
- Click “view map in full screen”
- Click “show legend” to bring up local soil temperature
Use The Old Farmers Almanac
Yup, it’s been around a long time, but probably has the most useful information. The gardening experts at The Old Farmer’s Almanac can help you out if you still have questions. Planting tools are by zip code and they use weather station reports and using a “days until harvest” for popular vegetables grown in your area. Find out when to sow indoors, transplant, and start your garden or grass seed based on years of solid information.
You can find the current edition at Amazon: Old Farmers Almanac
Whether you’re planting seeds, planting a garden, applying fertilizer or targeting weeds, it’s important to check your soil temperature before beginning.
If temperatures are not right for the job, the results will be disappointing. Soil temperatures are taken at 4 inches below the soil surface under bare soil
For Example:
- Plant spring bulbs in the fall when the soil temperature drops below 60° F.
- Apply crabgrass control in spring, when soil temperatures reach 55° F for 4-5 days in a row.
- Plant cool-season grass seed once soil temperatures are in the 50s F.
- Give fall planting shrubs and trees time to grow roots before soil temperatures are below 40° F.
You Can Also Purchase A Soil Thermometer
You can find soil temperature thermometers at Lowes and on Amazon here: Amazon Garden Supplies.
Outdoor garden and soil thermometers help you keep your plants healthy and improve seeding, transplanting and crabgrass/fertilizer application times. Ensure great results by following application guidelines.
Weather resistant stainless steel models are perfect for temperature readings for indoor potting or outdoor gardening. They generally will cost from $10-$35
Soil Temperature Map: Click here for your Daily Updated Map