One of the first steps you take when you are figuring out 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.

You can determine when it's possible to plant ageratum in Williamsburg by looking at the USDA zone info.

Planting Calendar for Ageratum

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

Ageratum require warm weather which means that you really should wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant ageratum in Williamsburg 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. Any later than that and your ageratum may not have a chance to fully mature. If you are starting your ageratum indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Williamsburg. In the coldest months of winter you should expect an average low temperature of 5°F.

Remember that USDA zone info for Williamsburg is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Williamsburg it frosts late in the year after April 15 so just be sure to be ready to cover your ageratum in the event of one of those late frosts.

USDA Zone Info for Williamsburg

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Williamsburg

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