One of the first steps you take when you are getting a good idea 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.

By using the USDA zone info for Salem you should be able to figure out when you can plant ageratum.

Planting Calendar for Ageratum

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

Since ageratum require warm weather it's necessary to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant ageratum in Salem 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 few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Salem. It might get as low as -10°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Salem is not always accurate and the actual date of last frost will vary from year to year. Since half of the time in Salem you get surprised by a frost after April 15 be ready to cover your ageratum in the event of one of those late frosts.

USDA Zone Info for Salem

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°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 -5°F.

Plants to Grow in Salem

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