When to Plant Helianthemum in Phoenixville, PA

The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Phoenixville can be used to estimate when you can 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 ok in some cold which tells us that you can plant them a little earlier in the year than plants that are more sensitive to the cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant helianthemum
Possibly ok, but a risky time to plant helianthemum
Probably not a good time to plant helianthemum

The earliest that you can plant helianthemum in Phoenixville 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. You probably don't want to wait any later than that or else your helianthemum may not have a chance to fully mature. If you are starting your helianthemum indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

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

It's important to remember that USDA zone info for Phoenixville may not be accurate from year to year and the actual date of last frost is different every year. Half of the time in Phoenixville there is a last frost after April 15 so make sure that you are prepared to cover your helianthemum in the event of a late frost.

USDA Zone Info for Phoenixville

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 Low0°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 Phoenixville

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