When to Plant Zinnia in Wilmington, DE

One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can estimate when it's the best time to plant zinnia in Wilmington by referring to the USDA zone info.


Planting Calendar for Zinnia

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

Since zinnia are not cold tolerant it's necessary to wait until after all chance of 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 Wilmington 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. Any later than that and your zinnia may not have a chance to grow to maturity. You can get started a little bit earlier by starting your zinnia indoors.

Last Frost Date

In Wilmington the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of 0°F.

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Wilmington and it will vary from year to year. Half of the time in Wilmington last frost occurs after April 15 so make sure that you are prepared to cover your zinnia in the event of a surprise late frost.

USDA Zone Info for Wilmington

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low0°F
Highest Expected Low5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Wilmington

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