One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant ageratum in Downingtown can be estimated by using the USDA zone info.

Planting Calendar for Ageratum

Frost tolerance for ageratum:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

It's probably a bad idea to plant ageratum until after the last frost when the weather gets warmer because they require warm weather.

The earliest that you can plant ageratum in Downingtown 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. Starting your ageratum indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Downingtown. You can expect an average low temperature of -5°F in the coldest months of winter.

Since the USDA zone info for Downingtown is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Downingtown it frosts late in the year after April 15 so always be ready to protect your ageratum if you have one of those late frosts.

USDA Zone Info for Downingtown

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°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 0°F.

Plants to Grow in Downingtown

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