When to Plant Dahlia in Lancaster, PA

The USDA Zone info is a great tool for gardeners to help us figure out 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.

It's a good idea to figure out when it's possible to plant dahlia by referring to the USDA zone info for Lancaster.


Planting Calendar for Dahlia

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

Dahlia are not cold tolerant which tells us that it is necessary to wait until it warms up after the last frost has passed before you can plant them.

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

The earliest that you can plant dahlia in Lancaster 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 dahlia and expect a good harvest is probably August. You probably don't want to wait any later than that or else your dahlia may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your dahlia indoors.

Last Frost Date

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

Since the USDA zone info for Lancaster is just an average the actual date of last frost is different every year. Half of the time in Lancaster you get surprised by a frost after April 15 so make sure that you are ready to cover your dahlia if you have a surprise late frost.

USDA Zone Info for Lancaster

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 Lancaster

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