One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By looking at the USDA zone info for Oroville you should be able to determine when you can plant calliopsis.

Planting Calendar for Calliopsis

Frost tolerance for calliopsis:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

It's probably not a good idea to plant calliopsis until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant calliopsis 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 calliopsis and expect a good harvest is probably September. You probably don't want to wait any later than that or else your calliopsis may not have a chance to really do well. If you are starting your calliopsis indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

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

Always keep in mind 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 Oroville and it can change quite a bit from year to year. Since half of the time in Oroville there is a last frost after February 15 be ready to protect your calliopsis if you have a late frost.

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.