The USDA Zone info is a great tool for gardeners to help us figure out 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 Washington can be used to estimate when it's the best time to plant ageratum.

Planting Calendar for Ageratum

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

Since ageratum require warm weather it's important to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant ageratum in Washington 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 grow to maturity. You can get started a couple of weeks earlier by starting your ageratum indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Washington. You should expect an average low temperature of -5°F in the coldest months of winter.

Always keep in mind that USDA zone info for Washington is an average and the actual date of last frost changes from year to year. Since half of the time in Washington last frost occurs after April 15 be ready to protect your ageratum in the event of one of those late frosts.

USDA Zone Info for Washington

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Washington

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