One of the best tools that you have as gardeners to help us figure out your gardening schedule is the 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.

In Broomfield you can estimate when to plant leeks 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 do ok in quite a bit of cold which means that you can plant them much earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant leeks in Broomfield 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 couple of weeks earlier by starting your leeks indoors.

Last Frost Date

In Broomfield the average date of last frost happens on April 15. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for Broomfield is just an average the actual date of last frost changes from year to year. Half of the time in Broomfield it frosts late in the year after April 15 so just be sure to be ready to cover your leeks in the event of a surprise late frost.

USDA Zone Info for Broomfield

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 Broomfield

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