When to Plant Argyranthemum in Portsmouth, NH

The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Portsmouth should be read to figure out when it's possible to plant argyranthemum.


Planting Calendar for Argyranthemum

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

Argyranthemum require warm weather which means that you must wait until it warms up after all chance of frost has passed before you can plant them.

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

The earliest that you can plant argyranthemum 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 argyranthemum and expect a good harvest is probably August. If you wait any later than that and your argyranthemum may not have a chance to fully mature. Starting your argyranthemum indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Portsmouth the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -10°F.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Portsmouth and it changes from year to year. Half of the time in Portsmouth you get surprised by a frost after April 15 so just be sure to be ready to cover your argyranthemum if you have a surprise 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.