When to Plant Catharanthus in Downers Grove, IL

Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's possible to estimate when it's the best time to plant catharanthus by reviewing the USDA zone info for Downers Grove.


Planting Calendar for Catharanthus

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

It's probably not a good idea to plant catharanthus until after the last frost because they do not do well in cold weather.

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

The earliest that you can plant catharanthus in Downers Grove 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 catharanthus and expect a good harvest is probably August. You probably don't want to wait any later than that or else your catharanthus may not have a chance to grow to maturity. You can get started a little bit earlier by starting your catharanthus indoors.

Last Frost Date

In Downers Grove the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Downers Grove and it will vary from year to year. Since half of the time in Downers Grove there is a last frost after April 15 be ready to cover your catharanthus in the event of one of those late frosts.

USDA Zone Info for Downers Grove

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 Downers Grove

You may be interested in your other planting guides for Downers Grove.