One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's a good idea to estimate when it's possible to plant primula by using the USDA zone info for Waukesha.

Planting Calendar for Primula

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

Primula do well in cold which tells us that you can plant them much earlier than other plants that might not handle the cold.

The earliest that you can plant primula in Waukesha 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. Any later than that and your primula may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your primula indoors.

Last Frost Date

In Waukesha the average date of last frost happens on April 15. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Waukesha 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 Waukesha there is a last frost after April 15 be ready to cover your primula if you have one of those late frosts.

USDA Zone Info for Waukesha

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 Waukesha

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