When to Plant Zinnia in Princeton, IL

Before planting it is a good idea to find your USDA Zone info to estimate 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.

The first chance to plant zinnia in Princeton can be figured out by checking out the USDA zone info.


Planting Calendar for Zinnia

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

Since zinnia require warm weather it's important to wait until 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 Princeton 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 fully mature. You can get started a little bit earlier by starting your zinnia indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Princeton. In the coldest months of winter you can expect an average low temperature of -15°F.

Since the USDA zone info for Princeton may not be accurate from year to year the actual date of last frost changes from year to year. Since half of the time in Princeton you get surprised by a frost after April 15 be ready to cover your zinnia if you have a surprise late frost.

USDA Zone Info for Princeton

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 Princeton

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