Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Middlesex can be read to estimate when it's a good idea to plant primula.

Planting Calendar for Primula

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

You can plant primula a lot earlier in the year because they are one of those plants that can tolerate quite a bit of cold weather.

The earliest that you can plant primula in Middlesex 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. Starting your primula indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Middlesex the average date of last frost happens on April 15. It might get as low as -5°F during the coldest months of winter.

Since the USDA zone info for Middlesex is just an average the actual date of last frost will vary from year to year. Half of the time in Middlesex you get surprised by a frost after April 15 so make sure that you are ready to protect your primula in the event of one of those late frosts.

USDA Zone Info for Middlesex

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Middlesex

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