When to Plant Cleome in Portsmouth, NH

One of the first steps you take when you are determining 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.

A way of getting a good idea when it's the best time to plant cleome is to refer to the USDA zone info for Portsmouth.


Planting Calendar for Cleome

Frost tolerance for cleome: Not tolerant of frost.
When to plant: After the last frost has passed.

Since cleome do not do well in cold weather you really should wait until after the last frost when the weather gets warmer before you can plant them.

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

The earliest that you can plant cleome 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 cleome and expect a good harvest is probably August. You probably don't want to wait any later than that or else your cleome may not have a chance to really do well. Starting your cleome 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. You should expect an average low temperature of -10°F in the coldest months of winter.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Portsmouth and it will vary from year to year. Since half of the time in Portsmouth you get a frost after April 15 be ready to protect your cleome 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.