One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By using the USDA zone info for Columbia it's possible to figure out 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.

Leeks tend to make it in pretty solid cold 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 Columbia 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. 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

In Columbia the average date of last frost happens on March 15. In the coldest months of winter you should expect an average low temperature of 15°F.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Columbia and it will vary from year to year. Since half of the time in Columbia you get a frost after March 15 be ready to cover your leeks if you have one of those late frosts.

USDA Zone Info for Columbia

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in Columbia

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