Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By referring to the USDA zone info for Riverbank you should be able to determine when it's possible to plant twinspur.

Planting Calendar for Twinspur

Frost tolerance for twinspur:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Twinspur tend to make it in some cold which tells us that you can plant them a little earlier in the year than more sensitive plants.

The earliest that you can plant twinspur in Riverbank is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant twinspur and expect a good harvest is probably October. You probably don't want to wait any later than that or else your twinspur may not have a chance to grow to maturity. If you are starting your twinspur indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Riverbank 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.

Just be sure to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Riverbank and it changes from year to year. Half of the time in Riverbank there is a last frost after February 15 so always be ready to protect your twinspur if you have a surprise late frost.

USDA Zone Info for Riverbank

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 Riverbank

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