Before planting it is a good idea to find your USDA Zone info to estimate 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.

A way of getting a good idea when it's the best time to plant iresene is to refer to the USDA zone info for Colusa.

Planting Calendar for Iresene

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

Iresene do not do well in cold weather which tells us that you have to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant iresene 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 iresene and expect a good harvest is probably September. If you wait any later than that and your iresene may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your iresene indoors.

Last Frost Date

In Colusa 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.

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 Colusa and it is different every year. Half of the time in Colusa you get a frost after February 15 so make sure that you are ready to protect your iresene in the event of a 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.