Before planting it is a good idea to find your USDA Zone info to determine 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 estimating when it's a good idea to plant primula is to look at the USDA zone info for Golden.

Planting Calendar for Primula

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

Primula are very cold tolerant which means that you can plant them a quite a bit earlier than more sensitive plants.

The earliest that you can plant primula in Golden 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 primula and expect a good harvest is probably September. If you wait any later than that and your primula may not have a chance to really do well. You can get started a little bit earlier by starting your primula indoors.

Last Frost Date

On average the last frost is on April 15 in Golden. You should expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Golden is an average the actual date of last frost is different every year. Half of the time in Golden you get surprised by a frost after April 15 so make sure that you are ready to protect your primula in the event of a late frost.

USDA Zone Info for Golden

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Golden

You may be interested in your other planting guides for Golden.