The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By reviewing the USDA zone info for Altoona you will be able to estimate when to plant tall phlox.

Planting Calendar for Tall Phlox

Frost tolerance for tall phlox:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Tall Phlox are one of those plants that can tolerate a little bit of cold weather which means that you can plant them earlier than other plants that might not handle the cold.

The earliest that you can plant tall phlox in Altoona is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant tall phlox and expect a good harvest is probably September. Any later than that and your tall phlox may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your tall phlox indoors.

Last Frost Date

The average date of last frost is April 15 in Altoona. You can expect an average low temperature of -20°F in the coldest months of winter.

Since the USDA zone info for Altoona is not always accurate the actual date of last frost changes from year to year. Since half of the time in Altoona there is a last frost after April 15 be ready to protect your tall phlox 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.