Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Alton should be looked at to figure out when you can plant saxifraga.

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 do ok in some cold which means that you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant saxifraga in Alton 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 saxifraga and expect a good harvest is probably August. If you wait any later than that and your saxifraga may not have a chance to really do well. Starting your saxifraga indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Alton the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -10°F.

Always keep in mind that USDA zone info for Alton is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Alton there is a last frost after April 15 so be sure to be ready to protect your saxifraga in the event of a late frost.

USDA Zone Info for Alton

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Alton

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