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 earliest that you can plant ageratum in Holly should be determined by referring to the USDA zone info.

Planting Calendar for Ageratum

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

You can not plant ageratum until after the last frost because they are not cold tolerant.

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

Last Frost Date

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

Since the USDA zone info for Holly is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Holly last frost occurs after April 15 so always be ready to protect your ageratum if you have a surprise late frost.

USDA Zone Info for Holly

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 Holly

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