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.

By reviewing the USDA zone info for Grass Valley it's a good idea to determine when to plant impatiens.

Planting Calendar for Impatiens

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

You really shouldn't plant impatiens until after the last frost when the weather gets warmer because they are not cold tolerant.

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

Last Frost Date

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

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Grass Valley and it changes from year to year. Half of the time in Grass Valley you get surprised by a frost after February 15 so just be sure to be ready to protect your impatiens if you have one of those late frosts.

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.