One of the best tools that you have as gardeners to help us estimate 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.

By reviewing the USDA zone info for Zone 5b it's a good idea to estimate when it's a good idea to 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.

You can plant saxifraga a bit earlier in the year because they are barely cold tolerant.

The earliest that you can plant saxifraga in Zone 5b 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. Any later than that and your saxifraga may not have a chance to really do well. You can get started a couple of weeks earlier by starting your saxifraga indoors.

Last Frost Date

The average date of last frost is April 15 in Zone 5b. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Zone 5b may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Zone 5b there is a last frost after April 15 so just be sure to be ready to protect your saxifraga if you have a late frost.

USDA Zone Info for Zone 5b

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Zone 5b

You may be interested in your other planting guides for Zone 5b.