One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Lisle can be read to estimate when it's a good idea to plant tritoma.

Planting Calendar for Tritoma

Frost tolerance for tritoma:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Tritoma can survive in pretty solid cold which means that you can plant them a lot earlier in the year than more sensitive plants.

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

The last month that you can plant tritoma and expect a good harvest is probably September. Any later than that and your tritoma may not have a chance to fully mature. You can get started a few weeks earlier by starting your tritoma indoors.

Last Frost Date

The average date of last frost is April 15 in Lisle. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for Lisle is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Lisle there is a last frost after April 15 be ready to cover your tritoma in the event of a surprise late frost.

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.