When to Plant Hibiscus in Keene, NH

The USDA Zone info is a great tool for gardeners to help us determine 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 Keene should be read to figure out when it's possible to plant hibiscus.


Planting Calendar for Hibiscus

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

It's not a good idea to plant hibiscus until after the last frost has passed because they are not cold tolerant.

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

The earliest that you can plant hibiscus in Keene 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 hibiscus and expect a good harvest is probably August. Any later than that and your hibiscus may not have a chance to grow to maturity. If you are starting your hibiscus indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Keene the average date of last frost happens on April 15. You can expect an average low temperature of -15°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Keene and it will vary from year to year. Since half of the time in Keene you get surprised by a frost after April 15 be ready to cover your hibiscus if you have a late frost.

USDA Zone Info for Keene

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 Keene

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