When to Plant Garden Mums in Portsmouth, NH

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.

You can figure out when it's a good idea to plant garden mums in Portsmouth by using the USDA zone info.


Planting Calendar for Garden Mums

Frost tolerance for garden mums: Tolerant of some frost.
When to plant: Up to 5 weeks before last frost.

Since garden mums do well in moderate cold you can plant them a little earlier in the year than more sensitive plants.

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

The earliest that you can plant garden mums in Portsmouth is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant garden mums and expect a good harvest is probably September. If you wait any later than that and your garden mums may not have a chance to really do well. If you are starting your garden mums indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for Portsmouth is not always accurate the actual date of last frost changes from year to year. Half of the time in Portsmouth it frosts late in the year after April 15 so make sure that you are prepared to protect your garden mums if you have 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.