One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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.

A common way of determining when it's the best time to plant euphorbia is to check out the USDA zone info for Superior.

Planting Calendar for Euphorbia

Frost tolerance for euphorbia:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Euphorbia can survive in some cold which means that you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant euphorbia in Superior is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant euphorbia and expect a good harvest is probably August. You probably don't want to wait any later than that or else your euphorbia may not have a chance to fully mature. You can get started a little bit earlier by starting your euphorbia indoors.

Last Frost Date

In Superior the average date of last frost happens on May 15. It might get as low as -25°F during the coldest months of winter.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Superior and it changes from year to year. Half of the time in Superior there is a last frost after May 15 so just be sure to be ready to protect your euphorbia in the event of a late frost.

USDA Zone Info for Superior

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Superior

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