Before planting it is a good idea to find your USDA Zone info to determine 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 River Grove should be read to figure out when to plant leeks.

Planting Calendar for Leeks

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

Leeks do ok in pretty solid cold which tells us that you can plant them much earlier in the year than other frost tender plants.

The earliest that you can plant leeks in River Grove 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. You probably don't want to wait any later than that or else your leeks may not have a chance to fully mature. If you are starting your leeks indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in River Grove. You should expect an average low temperature of -15°F in the coldest months of winter.

Just be sure to remember that USDA zone info for River Grove is an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in River Grove you get surprised by a frost after April 15 be ready to protect your leeks if you have one of those late frosts.

USDA Zone Info for River Grove

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 River Grove

You may be interested in your other planting guides for River Grove.