One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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 USDA zone info for Haverhill should be reffered to in order to figure out when it's the best time 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 earlier in the year because they are very cold tolerant.

The earliest that you can plant primula in Haverhill 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 fully mature. You can get started a little bit earlier by starting your primula indoors.

Last Frost Date

The average date of last frost is April 15 in Haverhill. You can expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for Haverhill may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in Haverhill you get surprised by a frost after April 15 be ready to protect your primula in the event of a surprise late frost.

USDA Zone Info for Haverhill

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 Haverhill

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