Before planting it is a good idea to find your USDA Zone info to determine 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.

In Marshfield you can estimate when you can plant sunflowers by referring to the USDA zone info.

Planting Calendar for Sunflowers

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

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

The earliest that you can plant sunflowers in Marshfield 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. You probably don't want to wait any later than that or else your sunflowers may not have a chance to grow to maturity. Starting your sunflowers indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on May 15 in Marshfield. It might get as low as -25°F during the coldest months of winter.

Keep in mind that USDA zone info for Marshfield is just an average and the actual date of last frost is different every year. Since half of the time in Marshfield last frost occurs after May 15 be ready to protect your sunflowers in the event of one of those late frosts.

USDA Zone Info for Marshfield

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 Marshfield

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