The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By referring to the USDA zone info for Rio Vista it's a good idea to determine when it's possible to plant impatiens.

Planting Calendar for Impatiens

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

Impatiens are not cold tolerant which tells us that it's necessary to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant impatiens in Rio Vista 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. You probably don't want to wait any later than that or else your impatiens may not have a chance to fully mature. You can get started a few weeks earlier by starting your impatiens indoors.

Last Frost Date

On average all chance of frost has passed is on February 15 in Rio Vista. In the coldest months of winter you should expect an average low temperature of 25°F.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Rio Vista and it is different every year. Since half of the time in Rio Vista you get a frost after February 15 be ready to cover your impatiens if you have a surprise late frost.

USDA Zone Info for Rio Vista

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 Rio Vista

You may be interested in your other planting guides for Rio Vista.