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.

A common way of estimating when it's the best time to plant hibiscus is to examine the USDA zone info for Keene.

Planting Calendar for Hibiscus

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

Since hibiscus require warm weather you need to wait until after the last frost has passed before you can plant them.

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 fully mature. If you are starting your hibiscus indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Keene the average date of last frost happens on March 15. You should expect an average low temperature of 10°F in the coldest months of winter.

Since the USDA zone info for Keene is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Keene you get surprised by a frost after March 15 so make sure that you are prepared to cover your hibiscus if you have a surprise late frost.

USDA Zone Info for Keene

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Keene

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