Before planting it is a good idea to find your USDA Zone info to estimate your garden 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 Mountlake Terrace should be looked at to estimate when it's a good idea 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 do not do well in cold weather it's necessary 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 Mountlake Terrace 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. Starting your ageratum indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is March 15 in Mountlake Terrace. It might get as low as 15°F during the coldest months of winter.

Since the USDA zone info for Mountlake Terrace may not be accurate from year to year the actual date of last frost is different every year. Since half of the time in Mountlake Terrace last frost occurs after March 15 be ready to protect your ageratum if you have a surprise late frost.

USDA Zone Info for Mountlake Terrace

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

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

Plants to Grow in Mountlake Terrace

You may be interested in your other planting guides for Mountlake Terrace.