When can I plant Ageratum in Zone 3b

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

A way of determining when you can plant ageratum is to look at the USDA zone info for Zone 3b.


Planting Calendar for Ageratum

Frost tolerance for ageratum: Not tolerant of frost.
When you should plant them: After the last frost has passed.

You can not plant ageratum until after the last frost when the weather gets warmer because they are not cold tolerant.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant ageratum
Possibly ok, but a risky time to plant ageratum
Probably not a good time to plant ageratum

The earliest that you can plant ageratum in Zone 3b is May. However, you really should wait until June 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. 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

In Zone 3b the average date of last frost happens on May 15. It might get as low as -35°F during the coldest months of winter.

Remember that our actual date of last frost is an average because it is based on the USDA zone info for Zone 3b and it changes from year to year. Since half of the time in Zone 3b it frosts late in the year after May 15 be ready to cover your ageratum in the event of a late frost.

USDA Zone Info for Zone 3b

Here is the info for USDA Zone 3b.

Average Date of Last Frost (spring)May 15
Average Date of First Frost (fall)September 15
Lowest Expected Low-35°F
Highest Expected Low-30°F

This means that on a really cold year, the coldest it will get is -35°F. On most years you should be prepared to experience lows near -30°F.

Plants to Grow in Zone 3b

You may be interested in our other planting guides for Zone 3b.