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.

The earliest that you can plant primroses in Caldwell should be estimated by referring to 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 can survive in pretty solid cold which tells us that you can plant them a lot earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant primroses in Caldwell 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. Any later than that and your primroses may not have a chance to really do well. If you are starting your primroses indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Caldwell the average date of last frost happens on April 15. It might get as low as -5°F during the coldest months of winter.

Since the USDA zone info for Caldwell is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Caldwell you get surprised by a frost after April 15 so make sure that you are prepared to cover your primroses if you have one of those late frosts.

USDA Zone Info for Caldwell

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Caldwell

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