The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You should be able to estimate when it's a good idea to plant leeks by using the USDA zone info for Mill Valley.

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 cold weather which tells us that you can plant them a lot earlier in the year than other frost tender plants.

The earliest that you can plant leeks in Mill Valley is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant leeks and expect a good harvest is probably October. You probably don't want to wait any later than that or else your leeks may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your leeks indoors.

Last Frost Date

In Mill Valley the average date of last frost happens on January 31. It might get as low as 30°F during the coldest months of winter.

Since the USDA zone info for Mill Valley is just an average the actual date of last frost is different every year. Since half of the time in Mill Valley it frosts late in the year after January 31 be ready to cover your leeks if you have a late frost.

USDA Zone Info for Mill Valley

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°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 35°F.

Plants to Grow in Mill Valley

You may be interested in your other planting guides for Mill Valley.