One of the best tools that you have as gardeners to help us determine 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.

You will be able to determine when it's the best time to plant helianthemum by referring to the USDA zone info for Pottstown.

Planting Calendar for Helianthemum

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

Helianthemum can survive in moderate cold which tells us that you can plant them a little bit earlier in the year than more sensitive plants.

The earliest that you can plant helianthemum in Pottstown 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. Any later than that and your helianthemum may not have a chance to really do well. Starting your helianthemum indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Pottstown. In the coldest months of winter you can expect an average low temperature of -5°F.

Just be sure to remember that USDA zone info for Pottstown is just an average and the actual date of last frost is different every year. Half of the time in Pottstown there is a last frost after April 15 so just be sure to be ready to protect your helianthemum in the event of one of those late frosts.

USDA Zone Info for Pottstown

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 Pottstown

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