Cold, wet planting conditions: effect on sweet corn, beans, peas

Elaine Roddy, OMAFRA Vegetable Crop Specialist, Ridgetown

The soil temperature at time of planting can have a huge impact on the future growth and development of the crop.  Enzyme damage may occur when a dry seed absorbs cold water from the soil.  This damage can impact the speed at which the shoot and root emerge, even if the weather subsequently becomes more suitable for crop growth. 

Cold water damage to the seed can also reduce crop vigour for the rest of the early growth stages making the plants more prone insects and disease pressure.  These stresses often do not appear until the plant starts the rapid growth phase (3-5 leaves for sweet corn, 3rd trifoliate for beans).

Crop Minimum Soil Temperature (0°C)
Sweet Corn
-normal (su) 13
-sugar enhanced (se) 16
-supersweet (sh2) 18
Beans, snap 13
Beans, lima 15

Ideally we like to see the crop emerge within 7-10 days of planting.  See the table below for an outline of the time required for crop emergence at various different temperatures.

Days Required for Seedling Emergence at Various Soil Temperatures from Seed Planted 1/2″ deep.[1]

Soil Temperature (°F)

32 41 50 59 68 77 86
Sweet Corn NG NG 22 12 7 4 4
Snap Beans NG NG NG 16 11 8 6
Lima Beans NG 31 18 7 7
Peas 36 14 9 8 6 6

NG = no germination, – = not tested

[1] Maynard, D and G. Hochmuth, 1997.  Knott’s Handbook for Vegetable Growers, John Wiley and Sons Inc.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s