One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant phlox in Altoona can be figured out by looking at the USDA zone info.

Planting Calendar for Phlox

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

Phlox do well in moderate cold which means that you can plant them a little bit earlier than other plants that might not handle the cold.

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

The last month that you can plant phlox and expect a good harvest is probably August. If you wait any later than that and your phlox may not have a chance to grow to maturity. If you are starting your phlox indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Altoona. You should expect an average low temperature of -25°F in the coldest months of winter.

Since the USDA zone info for Altoona is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Altoona there is a last frost after May 15 so make sure that you are prepared to cover your phlox in the event of one of those late frosts.

USDA Zone Info for Altoona

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Altoona

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