When to Plant Dianthus in Norristown, PA

The USDA Zone info is a great tool for gardeners to help us estimate 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 Norristown should be used to estimate when it's the best time to plant dianthus.


Planting Calendar for Dianthus

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

Dianthus do ok in a little bit of cold which tells us that you can plant them just a bit earlier in the year than other frost tender plants.

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

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

Last Frost Date

The average date of last frost is April 15 in Norristown. You should expect an average low temperature of 0°F in the coldest months of winter.

Since the USDA zone info for Norristown is not always accurate the actual date of last frost is different every year. Half of the time in Norristown you get surprised by a frost after April 15 so just be sure to be ready to cover your dianthus if you have one of those late frosts.

USDA Zone Info for Norristown

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 Low0°F
Highest Expected Low5°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 Norristown

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