When to Plant Sunflowers in Spring Valley, IL

Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can determine when to plant sunflowers in Spring Valley by using the USDA zone info.


Planting Calendar for Sunflowers

Frost tolerance for sunflowers: Not tolerant of frost.
When to plant: After the last frost has passed.

Since sunflowers are not cold tolerant it's important to wait until after the last frost when the weather gets warmer before you can plant them.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant sunflowers
Possibly ok, but a risky time to plant sunflowers
Probably not a good time to plant sunflowers

The earliest that you can plant sunflowers in Spring Valley is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant sunflowers and expect a good harvest is probably August. You probably don't want to wait any later than that or else your sunflowers may not have a chance to grow to maturity. If you are starting your sunflowers indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Spring Valley the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Spring Valley is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Spring Valley you get a frost after April 15 be ready to protect your sunflowers if you have a late frost.

USDA Zone Info for Spring Valley

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-15°F
Highest Expected Low-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Spring Valley

You may be interested in your other planting guides for Spring Valley.