The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You will be able to figure out when to plant romanesco by referring to the USDA zone info for Willmar.

Planting Calendar for Romanesco

Frost tolerance for romanesco:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since romanesco are one of those plants that can tolerate a little bit of cold weather you can plant them just a bit earlier in the year than more sensitive plants.

The earliest that you can plant romanesco in Willmar is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant romanesco and expect a good harvest is probably August. Any later than that and your romanesco may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your romanesco indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on May 15 in Willmar. In the coldest months of winter you should expect an average low temperature of -25°F.

Since the USDA zone info for Willmar 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 Willmar it frosts late in the year after May 15 be ready to protect your romanesco in the event of a late frost.

USDA Zone Info for Willmar

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 Willmar

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