One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of figuring out when it's a good idea to plant zinnia is to check out the USDA zone info for Hartland.

Planting Calendar for Zinnia

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

Zinnia are not cold tolerant which means that it's necessary to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant zinnia in Hartland 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 really do well. If you are starting your zinnia indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost is on April 15 in Hartland. In the coldest months of winter you should expect an average low temperature of -20°F.

It's important to remember that USDA zone info for Hartland is just an average and the actual date of last frost is different every year. Half of the time in Hartland you get a frost after April 15 so make sure that you are ready to cover your zinnia if you have a surprise late frost.

USDA Zone Info for Hartland

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Hartland

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