One of the first steps you take when you are making a decision about 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 looking at the USDA zone info for Hummelstown it's possible to determine when it's the best time 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.

Since helianthemum are moderately cold tolerant you can plant them a little bit earlier in the year than other frost tender plants.

The earliest that you can plant helianthemum in Hummelstown 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 grow to maturity. You can get started a few weeks earlier by starting your helianthemum indoors.

Last Frost Date

On average the last frost is on April 15 in Hummelstown. In the coldest months of winter you should expect an average low temperature of 0°F.

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

USDA Zone Info for Hummelstown

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Hummelstown

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