One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of making a decision about when it's a good idea to plant primula is to look at the USDA zone info for Costa Mesa.

Planting Calendar for Primula

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

Primula do well in a bit of cold which means that you can plant them much earlier in the year than more sensitive plants.

The earliest that you can plant primula in Costa Mesa 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 primula and expect a good harvest is probably October. You probably don't want to wait any later than that or else your primula may not have a chance to grow to maturity. If you are starting your primula 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 Costa Mesa. It might get as low as 35°F during the coldest months of winter.

Remember that USDA zone info for Costa Mesa is not always accurate and the actual date of last frost is different every year. Half of the time in Costa Mesa you get a frost after January 31 so make sure that you are prepared to protect your primula in the event of a surprise late frost.

USDA Zone Info for Costa Mesa

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 Costa Mesa

You may be interested in your other planting guides for Costa Mesa.