Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

One way of getting a good idea when it's the best time to plant sunflowers is to check out the USDA zone info for Marshall.

Planting Calendar for Sunflowers

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

Since sunflowers do not do well in cold weather you must wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant sunflowers in Marshall is May. However, you really should wait until June 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 grow to maturity. You can get started a couple of weeks earlier by starting your sunflowers indoors.

Last Frost Date

On average the last frost has passed is on May 15 in Marshall. In the coldest months of winter you should expect an average low temperature of -25°F.

Since the USDA zone info for Marshall is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Marshall you get a frost after May 15 be ready to cover your sunflowers if you have one of those late frosts.

USDA Zone Info for Marshall

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Marshall

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