One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first chance to plant romanesco in Portsmouth should be estimated by referring to 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.

You can plant romanesco just a bit earlier in the year because they do well in moderate cold.

The earliest that you can plant romanesco in Portsmouth 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 fully mature. If you are starting your romanesco indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Portsmouth. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for Portsmouth 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 Portsmouth you get surprised by a frost after April 15 be ready to cover your romanesco in the event of a surprise late frost.

USDA Zone Info for Portsmouth

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Portsmouth

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