One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of getting a good idea when to plant saxifraga is to refer to the USDA zone info for Altoona.

Planting Calendar for Saxifraga

Frost tolerance for saxifraga:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Saxifraga are one of those plants that can tolerate a tiny bit of cold weather which tells us that you can start planting them slightly earlier than more sensitive plants.

The earliest that you can plant saxifraga 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 saxifraga and expect a good harvest is probably August. You probably don't want to wait any later than that or else your saxifraga may not have a chance to fully mature. You can get started a little bit earlier by starting your saxifraga indoors.

Last Frost Date

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

Since the USDA zone info for Altoona is an average the actual date of last frost is different every year. Half of the time in Altoona it frosts late in the year after May 15 so make sure that you are prepared to cover your saxifraga in the event of a late frost.

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.