The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of making a decision about when it's the best time to plant catharanthus is to examine the USDA zone info for Marshfield.

Planting Calendar for Catharanthus

Frost tolerance for catharanthus:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Catharanthus are not cold tolerant which tells us that it's important to wait until it warms up after the last frost before you can plant them.

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

The last month that you can plant catharanthus and expect a good harvest is probably August. Any later than that and your catharanthus may not have a chance to fully mature. Starting your catharanthus indoors is a great way to get them started a few weeks earlier.

Last Frost Date

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

Always keep in mind that USDA zone info for Marshfield is just an average and the actual date of last frost is different every year. Half of the time in Marshfield last frost occurs after May 15 so just be sure to be ready to protect your catharanthus in the event of a surprise late frost.

USDA Zone Info for Marshfield

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 Marshfield

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