When to Plant Dahlia in New Castle, PA

Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant dahlia in New Castle should be figured out by checking out the USDA zone info.


Planting Calendar for Dahlia

Frost tolerance for dahlia: Not tolerant of frost.
When to plant: After the last frost has passed.

It's a bad idea to plant dahlia until after the last frost has passed because they do not do well in cold weather.

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 New Castle 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. If you wait any later than that and your dahlia may not have a chance to fully mature. Starting your dahlia indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in New Castle. You can expect an average low temperature of -10°F in the coldest months of winter.

It's important to remember that USDA zone info for New Castle 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 New Castle there is a last frost after April 15 so always be ready to protect your dahlia if you have a late frost.

USDA Zone Info for New Castle

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-10°F
Highest Expected Low-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in New Castle

You may be interested in your other planting guides for New Castle.