One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Westminster you can determine when to plant ageratum 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.

Since ageratum do not do well in cold weather it's important to wait until after the last frost before you can plant them.

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. You can get started a few weeks earlier by starting your ageratum indoors.

Last Frost Date

In Westminster the average date of last frost happens on April 15. You can expect an average low temperature of -15°F in the coldest months of winter.

It's important to remember that USDA zone info for Westminster may not be accurate from year to year and the actual date of last frost is different every year. Since half of the time in Westminster you get surprised by a frost after April 15 be ready to protect your ageratum if you have a late frost.

USDA Zone Info for Westminster

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Westminster

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