One of the first steps you take when you are estimating 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.

The first opportunity to plant primroses in Rancho Cucamonga can be estimated by looking at the USDA zone info.

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 much earlier than other plants that might not handle the cold.

The earliest that you can plant primroses in Rancho Cucamonga 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. If you wait any later than that and your primroses may not have a chance to fully mature. Starting your primroses indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in Rancho Cucamonga. It might get as low as 25°F during the coldest months of winter.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Rancho Cucamonga and it will vary from year to year. Since half of the time in Rancho Cucamonga it frosts late in the year after February 15 be ready to cover your primroses if you have a surprise late frost.

USDA Zone Info for Rancho Cucamonga

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 Rancho Cucamonga

You may be interested in your other planting guides for Rancho Cucamonga.