The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Harvey you can determine when to plant zinnia 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 when the weather gets warmer.

Zinnia do not do well in cold weather which means that it's important to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant zinnia in Harvey 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 fully mature. You can get started a couple of weeks earlier by starting your zinnia indoors.

Last Frost Date

The average date of last frost is April 15 in Harvey. In the coldest months of winter you can expect an average low temperature of -15°F.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Harvey and it will vary from year to year. Half of the time in Harvey you get surprised by a frost after April 15 so make sure that you are prepared to protect your zinnia in the event of one of those late frosts.

USDA Zone Info for Harvey

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 Harvey

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