The USDA Zone info is a great tool for gardeners to help us estimate 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.

In Grinnell you can estimate when you can plant romanesco by checking out the USDA zone info.

Planting Calendar for Romanesco

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

Romanesco do well in moderate cold which means that you can plant them earlier than other frost tender plants.

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

The last month that you can plant romanesco and expect a good harvest is probably September. Any later than that and your romanesco may not have a chance to really do well. You can get started a couple of weeks earlier by starting your romanesco indoors.

Last Frost Date

In Grinnell the average date of last frost happens on April 15. You can expect an average low temperature of -20°F in the coldest months of winter.

Remember that USDA zone info for Grinnell may not be accurate from year to year and the actual date of last frost is different every year. Since half of the time in Grinnell you get a frost after April 15 be ready to cover your romanesco in the event of a late frost.

USDA Zone Info for Grinnell

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 Grinnell

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