Before planting it is a good idea to find your USDA Zone info to determine 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.

By using the USDA zone info for Downingtown you will be able to determine 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.

Primula do ok in cold weather which means that you can plant them earlier in the year than other frost tender plants.

The earliest that you can plant primula in Downingtown 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. You can get started a couple of weeks earlier by starting your primula indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Downingtown. You should expect an average low temperature of -5°F in the coldest months of winter.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Downingtown and it will vary from year to year. Since half of the time in Downingtown it frosts late in the year after April 15 be ready to cover your primula in the event of one of those late frosts.

USDA Zone Info for Downingtown

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 Downingtown

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