One of the first steps you take when you are making a decision about 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 Fort Collins you can estimate when it's a good idea 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 the last frost has passed.

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

The earliest that you can plant ageratum in Fort Collins 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. If you wait 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

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

Since the USDA zone info for Fort Collins is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Fort Collins last frost occurs after April 15 so be sure to be ready to cover your ageratum if you have a late frost.

USDA Zone Info for Fort Collins

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 Fort Collins

You may be interested in your other planting guides for Fort Collins.