One of the first steps you take when you are making a decision about 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.

In Grass Valley you can determine when to plant marigold by using the USDA zone info.

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 has passed because they are not cold tolerant.

The earliest that you can plant marigold in Grass Valley 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. You probably don't want to wait any later than that or else your marigold may not have a chance to grow to maturity. If you are starting your marigold indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Grass Valley the average date of last frost happens on February 15. It might get as low as 20°F during the coldest months of winter.

Since the USDA zone info for Grass Valley is not always accurate the actual date of last frost is different every year. Half of the time in Grass Valley there is a last frost after February 15 so make sure that you are prepared to protect your marigold in the event of a late frost.

USDA Zone Info for Grass Valley

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Grass Valley

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