Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to determine when to plant saxifraga by looking at the USDA zone info for Lisle.

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 just a tiny bit earlier in the year because they do ok in moderate cold.

The earliest that you can plant saxifraga in Lisle 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 fully mature. If you are starting your saxifraga indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Lisle. It might get as low as -15°F during the coldest months of winter.

Remember that USDA zone info for Lisle is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Lisle you get a frost after April 15 be ready to cover your saxifraga if you have one of those late frosts.

USDA Zone Info for Lisle

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 Lisle

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