One of the first steps you take when you are figuring out your gardening schedule is find your 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.

The USDA zone info for Denison should be reviewed to figure out when it's possible to plant ageratum.

Planting Calendar for Ageratum

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

Ageratum require warm weather which means that you must wait until it warms up after the last frost before you can plant them.

The earliest that you can plant ageratum in Denison 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 really do well. Starting your ageratum indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Denison the average date of last frost happens on April 15. It might get as low as -20°F during the coldest months of winter.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Denison and it changes from year to year. Since half of the time in Denison it frosts late in the year after April 15 be ready to cover your ageratum if you have one of those late frosts.

USDA Zone Info for Denison

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Denison

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