One of the best tools that you have as gardeners to help us determine 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 best time to plant ageratum in Westminster should be figured out by using the USDA zone info.

Planting Calendar for Ageratum

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

You can not 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 February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant ageratum and expect a good harvest is probably September. Any later than that and your ageratum may not have a chance to really do well. 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

In Westminster the average date of last frost happens on January 31. It might get as low as 35°F during the coldest months of winter.

Remember that USDA zone info for Westminster is just an average and the actual date of last frost changes from year to year. Half of the time in Westminster there is a last frost after January 31 so just be sure to be ready to cover your ageratum if you have a surprise late frost.

USDA Zone Info for Westminster

Here is the info for USDA Zone 10b.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	35°F
Highest Expected Low	40°F

This means that on a really cold year, the coldest it will get is 35°F. On most years you should be prepared to experience lows near 40°F.

Plants to Grow in Westminster

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