Before planting it is a good idea to find your USDA Zone info to estimate your garden 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 Rockville can be determined by looking at 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.

You should not plant ageratum until after the last frost because they do not do well in cold weather.

The earliest that you can plant ageratum in Rockville 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 grow to maturity. You can get started a few weeks earlier by starting your ageratum indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Rockville. It might get as low as 0°F during the coldest months of winter.

Keep in mind that USDA zone info for Rockville is just an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Rockville last frost occurs after April 15 be ready to cover your ageratum in the event of a late frost.

USDA Zone Info for Rockville

Here is the info for USDA Zone 7a.

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

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Rockville

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