When to Plant Helianthemum in Souderton, PA

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.

In Souderton you can figure out when it's the best time to plant helianthemum by reviewing 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.

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

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 Souderton 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 fully mature. You can get started a little bit earlier by starting your helianthemum indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Souderton. It might get as low as -5°F during the coldest months of winter.

Just be sure to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Souderton and it can change quite a bit from year to year. Since half of the time in Souderton you get surprised by a frost after April 15 be ready to cover your helianthemum if you have a late frost.

USDA Zone Info for Souderton

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 Souderton

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