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.

The first chance to plant leeks in Helena can be figured out by reviewing 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.

You can plant leeks much earlier in the year because they do well in cold.

The earliest that you can plant leeks in Helena 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 fully mature. If you are starting your leeks indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is May 15 in Helena. You can expect an average low temperature of -25°F in the coldest months of winter.

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Helena and it changes from year to year. Since half of the time in Helena it frosts late in the year after May 15 be ready to protect your leeks if you have one of those late frosts.

USDA Zone Info for Helena

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 Helena

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