One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant primula in Grafton should be estimated 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.

You can plant primula much earlier in the year because they are very cold tolerant.

The earliest that you can plant primula in Grafton 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. You probably don't want to wait any later than that or else your primula may not have a chance to really do well. 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 Grafton. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Grafton 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 Grafton you get a frost after April 15 be ready to protect your primula in the event of a surprise late frost.

USDA Zone Info for Grafton

Here is the info for USDA Zone 5b.

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

Plants to Grow in Grafton

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