Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant sunflowers in Grass Valley can be determined by reviewing the USDA zone info.

Planting Calendar for Sunflowers

Frost tolerance for sunflowers:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Sunflowers require warm weather which means that it's necessary to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant sunflowers 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 sunflowers and expect a good harvest is probably September. Any later than that and your sunflowers may not have a chance to fully mature. If you are starting your sunflowers indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on February 15 in Grass Valley. You can expect an average low temperature of 20°F in the coldest months of winter.

Since the USDA zone info for Grass Valley is not always accurate the actual date of last frost will vary from year to year. Half of the time in Grass Valley you get a frost after February 15 so always be ready to cover your sunflowers if you have a surprise 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.