When to Plant Catharanthus in Mount Horeb, WI

Before planting it is a good idea to find your USDA Zone info to estimate 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.

The earliest that you can plant catharanthus in Mount Horeb can be estimated by referring to the USDA zone info.


Planting Calendar for Catharanthus

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

Since catharanthus require warm weather it is important to wait until after all chance of frost has passed before you can plant them.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant catharanthus
Possibly ok, but a risky time to plant catharanthus
Probably not a good time to plant catharanthus

The earliest that you can plant catharanthus in Mount Horeb 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 catharanthus and expect a good harvest is probably August. Any later than that and your catharanthus may not have a chance to really do well. If you are starting your catharanthus indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Mount Horeb the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -20°F.

Remember that USDA zone info for Mount Horeb is not always accurate and the actual date of last frost is different every year. Half of the time in Mount Horeb you get surprised by a frost after April 15 so just be sure to be ready to cover your catharanthus in the event of a late frost.

USDA Zone Info for Mount Horeb

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-20°F
Highest Expected Low-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Mount Horeb

You may be interested in your other planting guides for Mount Horeb.