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.

In Westminster you can figure out when it's a good idea to plant ageratum by referring to 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 not a good idea to plant ageratum until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant ageratum in Westminster 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 little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Westminster. In the coldest months of winter you can expect an average low temperature of 0°F.

Since the USDA zone info for Westminster may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in Westminster there is a last frost after April 15 be ready to cover your ageratum in the event of a surprise late frost.

USDA Zone Info for Westminster

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 Westminster

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