One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of determining when to plant catharanthus is to look at the USDA zone info for Madison.

Planting Calendar for Catharanthus

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

Since catharanthus require warm weather it is necessary to wait until after the last frost has passed before you can plant them.

The earliest that you can plant catharanthus in Madison 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. Starting your catharanthus indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Madison the average date of last frost happens on March 15. You can expect an average low temperature of 10°F in the coldest months of winter.

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Madison and it can change quite a bit from year to year. Since half of the time in Madison last frost occurs after March 15 be ready to cover your catharanthus if you have one of those late frosts.

USDA Zone Info for Madison

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Madison

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