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.

By reviewing the USDA zone info for Willoughby it's possible to determine when you can plant primula.

Planting Calendar for Primula

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

Primula do well in quite a bit of cold which tells us that you can plant them quite a bit earlier in the year than plants that are more sensitive to the cold.

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

Last Frost Date

On average the last frost has passed is on April 15 in Willoughby. You should expect an average low temperature of -5°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Willoughby is an average and the actual date of last frost will vary from year to year. Half of the time in Willoughby you get surprised by a frost after April 15 so make sure that you are ready to cover your primula in the event of a surprise late frost.

USDA Zone Info for Willoughby

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 Willoughby

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