One of the best tools that you have as gardeners to help us figure out your gardening schedule is the 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.

One way of getting a good idea when it's the best time to plant marigold is to check out the USDA zone info for Walnut Creek.

Planting Calendar for Marigold

Frost tolerance for marigold:	Not tolerant of frost.
When to plant:	After the last frost has passed.

It's probably a bad idea to plant marigold until after the last frost has passed because they require warm weather.

The earliest that you can plant marigold in Walnut Creek 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 marigold and expect a good harvest is probably September. If you wait any later than that and your marigold may not have a chance to grow to maturity. You can get started a little bit earlier by starting your marigold indoors.

Last Frost Date

In Walnut Creek the average date of last frost happens on February 15. You can expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for Walnut Creek may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in Walnut Creek last frost occurs after February 15 so be sure to be ready to cover your marigold in the event of a surprise late frost.

USDA Zone Info for Walnut Creek

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°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 30°F.

Plants to Grow in Walnut Creek

You may be interested in your other planting guides for Walnut Creek.