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.

By reviewing the USDA zone info for Zone 10b you will be able to estimate when it's a good idea to plant primroses.

Planting Calendar for Primroses

Frost tolerance for primroses:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Primroses are one of those plants that can tolerate quite a bit of cold weather which means that you can plant them a quite a bit earlier than more sensitive plants.

The earliest that you can plant primroses in Zone 10b 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 primroses and expect a good harvest is probably October. Any later than that and your primroses may not have a chance to grow to maturity. If you are starting your primroses indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is January 31 in Zone 10b. You can expect an average low temperature of 35°F in the coldest months of winter.

Since the USDA zone info for Zone 10b may not be accurate from year to year the actual date of last frost is different every year. Half of the time in Zone 10b there is a last frost after January 31 so make sure that you are prepared to cover your primroses in the event of a late frost.

USDA Zone Info for Zone 10b

Here is the info for USDA Zone 10b.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	35°F
Highest Expected Low	40°F

This means that on a really cold year, the coldest it will get is 35°F. On most years you should be prepared to experience lows near 40°F.

Plants to Grow in Zone 10b

You may be interested in your other planting guides for Zone 10b.