One of the first steps you take when you are figuring out 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.

It's possible to estimate when you can plant romanesco by looking at the USDA zone info for Seattle.

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 are one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant romanesco in Seattle 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. If you wait any later than that and your romanesco may not have a chance to grow to maturity. If you are starting your romanesco indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is March 15 in Seattle. In the coldest months of winter you can expect an average low temperature of 15°F.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Seattle and it is different every year. Half of the time in Seattle there is a last frost after March 15 so make sure that you are prepared to protect your romanesco if you have one of those late frosts.

USDA Zone Info for Seattle

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Seattle

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