One of the first steps you take when you are figuring out 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.

You can estimate when it's possible to plant leeks in Zone 4b by using the USDA zone info.

Planting Calendar for Leeks

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

Leeks are one of those plants that can tolerate quite a bit of cold weather which tells us that you can plant them a quite a bit earlier than other plants that might not handle the cold.

The earliest that you can plant leeks in Zone 4b 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 leeks and expect a good harvest is probably August. Any later than that and your leeks may not have a chance to really do well. Starting your leeks indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on May 15 in Zone 4b. It might get as low as -25°F during the coldest months of winter.

Remember that USDA zone info for Zone 4b is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Zone 4b you get a frost after May 15 so make sure that you are prepared to protect your leeks if you have one of those late frosts.

USDA Zone Info for Zone 4b

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Zone 4b

You may be interested in your other planting guides for Zone 4b.