One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

One way of determining when it's possible to plant tropical hibiscus is to examine the USDA zone info for Keene.

Planting Calendar for Tropical Hibiscus

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

It's a bad idea to plant tropical hibiscus until after all chance of frost has passed because they are not cold tolerant.

The earliest that you can plant tropical 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 tropical hibiscus and expect a good harvest is probably August. You probably don't want to wait any later than that or else your tropical hibiscus may not have a chance to really do well. You can get started a little bit earlier by starting your tropical hibiscus indoors.

Last Frost Date

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

It's important to remember that the actual date of last frost is an average 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 last frost occurs after March 15 be ready to protect your tropical hibiscus in the event of 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.