One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Chelsea you can determine when it's possible to plant primula by looking at the USDA zone info.

Planting Calendar for Primula

Frost tolerance for primula:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Since primula do well in cold you can plant them earlier in the year than other frost tender plants.

The earliest that you can plant primula in Chelsea 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 primula and expect a good harvest is probably September. Any later than that and your primula may not have a chance to really do well. If you are starting your primula indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Chelsea the average date of last frost happens on April 15. You should expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for Chelsea is an average the actual date of last frost changes from year to year. Half of the time in Chelsea you get a frost after April 15 so just be sure to be ready to protect your primula in the event of a surprise late frost.

USDA Zone Info for Chelsea

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 Chelsea

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