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

You can determine when to plant zinnia in Mchenry 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.

Zinnia do not do well in cold weather which means that it is necessary to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant zinnia in Mchenry 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 grow to maturity. 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

The average date of last frost is April 15 in Mchenry. You should expect an average low temperature of -15°F in the coldest months of winter.

It's important to remember that USDA zone info for Mchenry is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Mchenry there is a last frost after April 15 so make sure that you are ready to protect your zinnia in the event of a late frost.

USDA Zone Info for Mchenry

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 Mchenry

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