One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can figure out when you can plant zinnia in Altoona 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 require warm weather which tells us that it is necessary to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant zinnia in Altoona 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 few weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Altoona. It might get as low as -20°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 Altoona and it can change quite a bit from year to year. Half of the time in Altoona last frost occurs after April 15 so make sure that you are prepared to cover your zinnia in the event of a surprise late frost.

USDA Zone Info for Altoona

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 Altoona

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