Before planting it is a good idea to find your USDA Zone info to estimate 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 earliest that you can plant leeks in Great Falls should be determined 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 well in cold weather which means that you can plant them a lot earlier in the year than more sensitive plants.

The earliest that you can plant leeks in Great Falls 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. You can get started a few weeks earlier by starting your leeks indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on May 15 in Great Falls. In the coldest months of winter you can expect an average low temperature of -30°F.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Great Falls and it will vary from year to year. Since half of the time in Great Falls you get surprised by a frost after May 15 be ready to cover your leeks in the event of one of those late frosts.

USDA Zone Info for Great Falls

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Great Falls

You may be interested in your other planting guides for Great Falls.