When to Plant Catharanthus in Decatur, IL

The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first opportunity to plant catharanthus in Decatur can be figured out by reviewing the USDA zone info.


Planting Calendar for Catharanthus

Frost tolerance for catharanthus: Not tolerant of frost.
When to plant: After all chance of frost has passed.

You can not plant catharanthus until after the last frost has passed because they are not cold tolerant.

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 Decatur 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 really do well. You can get started a few weeks earlier by starting your catharanthus indoors.

Last Frost Date

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

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Decatur and it is different every year. Half of the time in Decatur you get a frost after April 15 so make sure that you are ready to cover your catharanthus if you have a surprise late frost.

USDA Zone Info for Decatur

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 Decatur

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