One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can determine when to plant impatiens in Colusa by checking out the USDA zone info.

Planting Calendar for Impatiens

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

Since impatiens are not cold tolerant it's necessary to wait until after the last frost before you can plant them.

The earliest that you can plant impatiens in Colusa 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 grow to maturity. Starting your impatiens indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost is on February 15 in Colusa. You should expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for Colusa is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Colusa you get surprised by a frost after February 15 be ready to protect your impatiens if you have a surprise late frost.

USDA Zone Info for Colusa

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 Colusa

You may be interested in your other planting guides for Colusa.