Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can figure out when it's the best time to plant helianthemum in Johnstown by using the USDA zone info.

Planting Calendar for Helianthemum

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

Helianthemum are one of those plants that can tolerate a little bit of cold weather which tells us that you can plant them earlier than other frost tender plants.

The earliest that you can plant helianthemum in Johnstown 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 couple of weeks earlier.

Last Frost Date

In Johnstown the average date of last frost happens on April 15. It might get as low as -20°F during the coldest months of winter.

Remember that USDA zone info for Johnstown is an average and the actual date of last frost is different every year. Since half of the time in Johnstown it frosts late in the year after April 15 be ready to cover your helianthemum if you have a late frost.

USDA Zone Info for Johnstown

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Johnstown

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