When to Plant Zinnia in Robinson, 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 USDA zone info for Robinson should be used to determine when it's a good idea to plant zinnia.


Planting Calendar for Zinnia

Frost tolerance for zinnia: Not tolerant of frost.
When to plant: After the last frost has passed.

Zinnia do not do well in cold weather which tells us that it is important to wait until it warms up after the last frost has passed before you can plant them.

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

The earliest that you can plant zinnia in Robinson 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 zinnia and expect a good harvest is probably August. If you wait any later than that and your zinnia may not have a chance to grow to maturity. Starting your zinnia indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Robinson the average date of last frost happens on April 15. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for Robinson may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in Robinson it frosts late in the year after April 15 be ready to cover your zinnia in the event of a late frost.

USDA Zone Info for Robinson

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-10°F
Highest Expected Low-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Robinson

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