Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Zone 4a you can determine when to plant steirodiscus by reviewing the USDA zone info.

Planting Calendar for Steirodiscus

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

Steirodiscus do ok in moderate cold which tells us that you can get them planted just a bit earlier than more sensitive plants.

The earliest that you can plant steirodiscus in Zone 4a 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 steirodiscus and expect a good harvest is probably August. If you wait any later than that and your steirodiscus may not have a chance to really do well. If you are starting your steirodiscus indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Zone 4a the average date of last frost happens on May 15. It might get as low as -30°F during the coldest months of winter.

Always keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Zone 4a and it changes from year to year. Half of the time in Zone 4a it frosts late in the year after May 15 so make sure that you are ready to protect your steirodiscus in the event of a late frost.

USDA Zone Info for Zone 4a

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Zone 4a

You may be interested in your other planting guides for Zone 4a.