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

By checking out the USDA zone info for Waterloo you should be able to determine when it's the best time 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.

Since leeks do well in cold you can plant them much earlier in the year than more sensitive plants.

The earliest that you can plant leeks in Waterloo 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. If you are starting your leeks indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Waterloo. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for Waterloo may not be accurate from year to year the actual date of last frost changes from year to year. Since half of the time in Waterloo 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 Waterloo

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 Waterloo

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