When to Plant Alyssum in Willowbrook, IL

One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The earliest that you can plant alyssum in Willowbrook should be figured out by looking at the USDA zone info.


Planting Calendar for Alyssum

Frost tolerance for alyssum: Very tolerant of frost.
When to plant: Up to 7 weeks before last frost.

Alyssum do ok in pretty solid cold which means that you can plant them earlier in the year than more sensitive plants.

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

The earliest that you can plant alyssum in Willowbrook is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant alyssum and expect a good harvest is probably September. You probably don't want to wait any later than that or else your alyssum may not have a chance to grow to maturity. If you are starting your alyssum 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 April 15 in Willowbrook. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for Willowbrook is just an average the actual date of last frost is different every year. Since half of the time in Willowbrook there is a last frost after April 15 be ready to cover your alyssum in the event of a late frost.

USDA Zone Info for Willowbrook

Here is the info for USDA Zone 5b.

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

Plants to Grow in Willowbrook

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