When to Plant Dahlias in Columbia, PA

One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can determine when it's a good idea to plant dahlias in Columbia by checking out the USDA zone info.


Planting Calendar for Dahlias

Frost tolerance for dahlias: Not tolerant of frost.
When to plant: After all chance of frost has passed.

Dahlias are not cold tolerant which tells us that you have to wait until it warms up after all chance of frost has passed 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 Columbia 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. You probably don't want to wait any later than that or else your dahlias may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your dahlias indoors.

Last Frost Date

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

Always keep in mind 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 Columbia and it is different every year. Since half of the time in Columbia you get surprised by a frost after April 15 be ready to protect your dahlias in the event of a surprise late frost.

USDA Zone Info for Columbia

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 Columbia

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