One of the best tools that you have as gardeners to help us figure out 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.

The best time to plant helianthemum in Keene should be determined by referring to the USDA zone info.

Planting Calendar for Helianthemum

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

Helianthemum tend to make it in moderate cold which tells us that you can plant them a little earlier in the year than more sensitive plants.

The earliest that you can plant helianthemum in Keene 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 helianthemum and expect a good harvest is probably September. Any later than that and your helianthemum may not have a chance to fully mature. Starting your helianthemum indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is March 15 in Keene. In the coldest months of winter you can expect an average low temperature of 10°F.

Always keep in mind that USDA zone info for Keene may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Keene there is a last frost after March 15 so make sure that you are prepared to protect your helianthemum if you have a 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.