How do tomato or lettuce seeds know when the temperature is right for germination? Well, this question will remain unanswered for now. We just know that it’s important that seeds have the right temperatures for germination. Germination temperature usually means soil temperature. During the day, soil stores heat. At night, soil releases heat into the atmosphere.

The University of Nebraska Video included below advocates for planting when soil temperatures are 10 degrees F (about 5 degrees C) above minimum germination temperatures. This concept is supported in our chart.

Seed Temperature Germination Chart

Source: Mostly from University of Oregon. Other information from other sources.

CropGermination
Minimum Soil
Temperature (°F)
Germination
Optimum Soil
Temperature
Range (°F)
Germination
Maximum Soil
Temperature (°F)
Days to
Germination
at Optimal
Temps
Asparagus5060-859514-18
Bean, lima6075-85854-10
Bean, snap6075-85954-10
Beet4060-85954-10
Broccoli4060-85957-10
Brussels sprouts4060-85953-10
Cabbage4060-85955-10
Carrot4065-85956
Cauliflower4065-85954-10
Celery4060-709510
Chinese cabbage4060-85954-10
Collards4060-85955-10
Corn5065-951054-10
Cucumber6065-951055-7
Eggplant6075-859510-15
Endive/Escarole3560-758510-14
Garlic3565-85957-14
Kale4060-85955-7
Kohlrabi4060-951055-10
Leeks3565-85958-16
Lettuce3560-75852-10
Muskmelon6075-951054-10
Mustard3560-75854-6
Okra6085-951057-12
Onion3565-85954-12
Parsley4065-85955-6 weeks
Parsnip3565-75855-28
Pea4065-75855-7
Pepper6065-75957-10
Pumpkin6085-951054-10
Radicchio3560-75855-7
Radish4065-85954-10
Spinach3565-75756-14
Squash6085-951057-10
Swiss chard4065-85957
Tomato5065-85955-7
Turnip4060-951053-10
Watermelon6070-951054-10

Our dilemma of germination temperatures of tomato or lettuce seeds is answered, as well as for many other vegetable gemination temperatures.

Video – Vegetable Soil Temperatures

Comments

Leave a Reply

More From Gardening Calendar

Bird Netting for Roses in Winter

Judith shares her secrets on getting her roses ready for winter, including using netting and snow cover. Discover just how she gets her roses prepped with her useful tips and tricks – even with her knee braces!

Fireweed

Fireweed for pollinators: discover the wild magenta willow plant with stunning blooms & its importance for pollinators. Visit North Carolina to witness Fireweed and its unique beauty, or learn more about its edibility, and its potential toxicity to animals.

Succession Gardening

a lot. So in summary, I have been enjoying Joe Gardener and “A Way To Garden&lrdquo; and learning a lot of interesting information in a short amount of time. Try it, you might like it. Experience the wonders of succession gardening to increase yields and extend the season in your vegetable garden! Follow Joe Gardener and "A Way to Garden" podcast to get amazing tips and tricks with landscape and shade gardening. Learn how to maximize your space and grow your crops in the comfort of your backyard!