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 Donna 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 the last frost has passed.

Ageratum require warm weather which tells us that it's necessary to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant ageratum in Donna is March. However, you really should wait until April 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 grow to maturity. You can get started a few weeks earlier by starting your ageratum indoors.

Last Frost Date

The average date of last frost is February 15 in Donna. It might get as low as 25°F during the coldest months of winter.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Donna and it is different every year. Since half of the time in Donna there is a last frost after February 15 be ready to cover your ageratum if you have a late frost.

USDA Zone Info for Donna

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Donna

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