When to Plant Dipladenia in Portsmouth, NH

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

The first opportunity to plant dipladenia in Portsmouth should be estimated by reviewing the USDA zone info.


Planting Calendar for Dipladenia

Frost tolerance for dipladenia: Not tolerant of frost.
When to plant: After the last frost.

Since dipladenia are not cold tolerant you have to wait until after all chance of frost has passed before you can plant them.

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

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

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Portsmouth. In the coldest months of winter you should expect an average low temperature of -10°F.

It's important to remember 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 Portsmouth and it is different every year. Since half of the time in Portsmouth last frost occurs after April 15 be ready to protect your dipladenia in the event of a late frost.

USDA Zone Info for Portsmouth

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 Portsmouth

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