When to Plant Dahlia in Rochester, NH

One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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.

You will be able to estimate when you can plant dahlia by using the USDA zone info for Rochester.


Planting Calendar for Dahlia

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

You should not plant dahlia until after the last frost because they require warm 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 Rochester 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. Starting your dahlia indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Rochester the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Remember that USDA zone info for Rochester is not always accurate and the actual date of last frost is different every year. Half of the time in Rochester there is a last frost after April 15 so just be sure to be ready to protect your dahlia if you have a surprise late frost.

USDA Zone Info for Rochester

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Rochester

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