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.

One way of making a decision about when it's the best time to plant sunflowers is to examine the USDA zone info for Oroville.

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 do not do well in cold weather which means that it's important to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant sunflowers in Oroville 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. If you wait any later than that and your sunflowers may not have a chance to fully mature. You can get started a few weeks earlier by starting your sunflowers indoors.

Last Frost Date

In Oroville the average date of last frost happens on February 15. You can expect an average low temperature of 25°F in the coldest months of winter.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Oroville and it will vary from year to year. Since half of the time in Oroville you get surprised by a frost after February 15 be ready to protect your sunflowers if you have one of those late frosts.

USDA Zone Info for Oroville

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 Oroville

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