One of the first steps you take when you are making a decision about 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.

In Red Bluff you can determine when it's a good idea to plant delphinium by using the USDA zone info.

Planting Calendar for Delphinium

Frost tolerance for delphinium:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Delphinium tend to make it in some cold which means that you can plant them slightly earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant delphinium in Red Bluff is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant delphinium and expect a good harvest is probably September. If you wait any later than that and your delphinium may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your delphinium indoors.

Last Frost Date

In Red Bluff 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.

Since the USDA zone info for Red Bluff is just an average the actual date of last frost will vary from year to year. Half of the time in Red Bluff you get surprised by a frost after February 15 so make sure that you are ready to protect your delphinium if you have one of those late frosts.

USDA Zone Info for Red Bluff

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 Red Bluff

You may be interested in your other planting guides for Red Bluff.