When to Plant Sunflowers in Marion, IA

The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant sunflowers in Marion can be determined by reviewing 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.

Sunflowers are not cold tolerant which tells us that it's important to wait until it warms up 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 Marion 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. If you wait any later than that and your sunflowers may not have a chance to really do well. You can get started a little bit earlier by starting your sunflowers indoors.

Last Frost Date

The average date of last frost is April 15 in Marion. It might get as low as -20°F during the coldest months of winter.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Marion and it can change quite a bit from year to year. Since half of the time in Marion there is a last frost after April 15 be ready to cover your sunflowers if you have one of those late frosts.

USDA Zone Info for Marion

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-20°F
Highest Expected Low-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Marion

You may be interested in your other planting guides for Marion.