When to Plant Dahlia in Johnstown, 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 zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Johnstown you can figure out when it's a good idea to plant dahlia by using the USDA zone info.


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 require warm weather which tells us that you really should wait until it warms up after the last frost when the weather gets warmer 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 Johnstown 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. Any later than that and your dahlia may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your dahlia indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Johnstown. In the coldest months of winter you should expect an average low temperature of -10°F.

Always keep in mind that USDA zone info for Johnstown is an average and the actual date of last frost is different every year. Half of the time in Johnstown you get surprised by a frost after April 15 so make sure that you are prepared to protect your dahlia in the event of a surprise late frost.

USDA Zone Info for Johnstown

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 Johnstown

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