The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Rhinelander you can estimate when it's the best time to plant gladiolus by reviewing the USDA zone info.

Planting Calendar for Gladiolus

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

Gladiolus are one of those plants that can tolerate a tiny bit of cold weather which means that you can plant them slightly earlier than more sensitive plants.

The earliest that you can plant gladiolus in Rhinelander 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 gladiolus and expect a good harvest is probably August. If you wait any later than that and your gladiolus may not have a chance to fully mature. Starting your gladiolus indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Rhinelander 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 USDA zone info for Rhinelander is not always accurate and the actual date of last frost is different every year. Since half of the time in Rhinelander it frosts late in the year after May 15 be ready to cover your gladiolus in the event of one of those late frosts.

USDA Zone Info for Rhinelander

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 Rhinelander

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