When to Plant Dahlias in Collegeville, 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 Collegeville you can figure out when you can plant dahlias by checking out the USDA zone info.


Planting Calendar for Dahlias

Frost tolerance for dahlias: Not tolerant of frost.
When to plant: After the last frost when the weather gets warmer.

Since dahlias require warm weather you need to wait until after the last frost when the weather gets warmer before you can plant them.

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

The earliest that you can plant dahlias in Collegeville is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant dahlias and expect a good harvest is probably August. If you wait any later than that and your dahlias may not have a chance to grow to maturity. If you are starting your dahlias indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Collegeville. It might get as low as 0°F during the coldest months of winter.

It's important to remember that USDA zone info for Collegeville may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Collegeville there is a last frost after April 15 so make sure that you are prepared to protect your dahlias in the event of a surprise late frost.

USDA Zone Info for Collegeville

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 Collegeville

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