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

In Troy you can figure out when to plant zinnia by looking at the USDA zone info.

Planting Calendar for Zinnia

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

It's probably not a good 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 Troy 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 fully mature. You can get started a few weeks earlier by starting your zinnia indoors.

Last Frost Date

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

Since the USDA zone info for Troy may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in Troy you get surprised by a frost after April 15 be ready to protect your zinnia in the event of a surprise late frost.

USDA Zone Info for Troy

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 Troy

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