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

The USDA zone info for Naperville can be looked at to figure out when it's possible to plant romanesco.

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 tells us that you can plant them a little bit earlier than other frost tender plants.

The earliest that you can plant romanesco in Naperville 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. You probably don't want to wait any later than that or else your romanesco may not have a chance to really do well. Starting your romanesco indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Naperville. In the coldest months of winter you can expect an average low temperature of -15°F.

Remember that USDA zone info for Naperville is just an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Naperville last frost occurs after April 15 so be sure to be ready to protect your romanesco if you have one of those late frosts.

USDA Zone Info for Naperville

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Naperville

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