The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for The Dalles should be reffered to in order to determine when to plant ageratum.

Planting Calendar for Ageratum

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

It's probably a bad idea to plant ageratum until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant ageratum in The Dalles 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. You probably don't want to wait any later than that or else 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 couple of weeks earlier.

Last Frost Date

The average date of last frost is March 15 in The Dalles. In the coldest months of winter you should expect an average low temperature of 10°F.

Since the USDA zone info for The Dalles is just an average the actual date of last frost will vary from year to year. Half of the time in The Dalles it frosts late in the year after March 15 so make sure that you are prepared to cover your ageratum in the event of one of those late frosts.

USDA Zone Info for The Dalles

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

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

Plants to Grow in The Dalles

You may be interested in your other planting guides for The Dalles.