One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By looking at the USDA zone info for Waterloo it's possible to estimate when it's a good idea to plant primroses.

Planting Calendar for Primroses

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

Primroses do ok in cold weather which tells us that you can plant them much earlier in the year than other frost tender plants.

The earliest that you can plant primroses in Waterloo 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 fully mature. You can get started a couple of weeks earlier by starting your primroses indoors.

Last Frost Date

The average date of last frost is April 15 in Waterloo. In the coldest months of winter you can expect an average low temperature of -5°F.

Since the USDA zone info for Waterloo is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Waterloo you get a frost after April 15 be ready to cover your primroses in the event of a late frost.

USDA Zone Info for Waterloo

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 Waterloo

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