One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By reviewing the USDA zone info for Doylestown you should be able to estimate when it's a good idea to plant helianthemum.

Planting Calendar for Helianthemum

Frost tolerance for helianthemum:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Helianthemum do well in moderate cold which tells us that you can plant them a little bit earlier than other frost tender plants.

The earliest that you can plant helianthemum in Doylestown 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 helianthemum and expect a good harvest is probably September. If you wait any later than that and your helianthemum may not have a chance to fully mature. Starting your helianthemum indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Doylestown. It might get as low as -5°F during the coldest months of winter.

Since the USDA zone info for Doylestown may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in Doylestown you get a frost after April 15 be ready to cover your helianthemum if you have a late frost.

USDA Zone Info for Doylestown

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 Doylestown

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