The USDA Zone info is a great tool for gardeners to help us determine your gardening 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 determining when you can plant primroses is to use the USDA zone info for Broomfield.

Planting Calendar for Primroses

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

Primroses are very cold tolerant which means that you can start planting them much earlier than more sensitive plants.

The earliest that you can plant primroses in Broomfield 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 primroses and expect a good harvest is probably September. You probably don't want to wait any later than that or else your primroses may not have a chance to really do well. You can get started a few weeks earlier by starting your primroses indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Broomfield. It might get as low as -10°F during the coldest months of winter.

Just be sure to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Broomfield and it can change quite a bit from year to year. Since half of the time in Broomfield you get surprised by a frost after April 15 be ready to protect your primroses in the event of one of those late frosts.

USDA Zone Info for Broomfield

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Broomfield

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