One of the first steps you take when you are estimating your gardening schedule is find your 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 common way of determining when to plant leeks is to refer to the USDA zone info for Bonne Terre.

Planting Calendar for Leeks

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

Leeks can survive in pretty solid cold which tells us that you can plant them much earlier in the year than other plants that might not handle the cold.

The earliest that you can plant leeks in Bonne Terre 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 leeks and expect a good harvest is probably September. If you wait any later than that and your leeks may not have a chance to fully mature. You can get started a few weeks earlier by starting your leeks indoors.

Last Frost Date

The average date of last frost is April 15 in Bonne Terre. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for Bonne Terre is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Bonne Terre you get surprised by a frost after April 15 so just be sure to be ready to cover your leeks if you have a surprise late frost.

USDA Zone Info for Bonne Terre

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 Bonne Terre

You may be interested in your other planting guides for Bonne Terre.