One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of estimating when it's a good idea to plant marigold is to examine the USDA zone info for Santa Rosa.

Planting Calendar for Marigold

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

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

The earliest that you can plant marigold in Santa Rosa 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 fully mature. Starting your marigold indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is February 15 in Santa Rosa. In the coldest months of winter you should expect an average low temperature of 25°F.

Since the USDA zone info for Santa Rosa may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in Santa Rosa it frosts late in the year after February 15 be ready to cover your marigold in the event of one of those late frosts.

USDA Zone Info for Santa Rosa

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 Santa Rosa

You may be interested in your other planting guides for Santa Rosa.