The USDA Zone info is a great tool for gardeners to help us determine 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 best time to plant zinnia in Delaware should be determined by reviewing 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.

It's a bad idea to plant zinnia until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant zinnia in Delaware 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. You probably don't want to wait any later than that or else your zinnia may not have a chance to grow to maturity. Starting your zinnia indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Delaware. It might get as low as -10°F during the coldest months of winter.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Delaware and it is different every year. Since half of the time in Delaware last frost occurs after April 15 be ready to protect your zinnia in the event of a late frost.

USDA Zone Info for Delaware

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 Delaware

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