The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can figure out when it's the best time to plant bunching onions in Mill Valley by checking out the USDA zone info.

Planting Calendar for Bunching Onions

Frost tolerance for bunching onions:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Bunching Onions tend to make it in very little cold which tells us that you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant bunching onions in Mill Valley 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 bunching onions and expect a good harvest is probably September. You probably don't want to wait any later than that or else your bunching onions may not have a chance to fully mature. You can get started a few weeks earlier by starting your bunching onions indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on January 31 in Mill Valley. In the coldest months of winter you can expect an average low temperature of 30°F.

Since the USDA zone info for Mill Valley is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Mill Valley it frosts late in the year after January 31 be ready to cover your bunching onions if you have a surprise 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.