One of the best tools that you have as gardeners to help us figure out 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.

The USDA zone info for Louisville should be reffered to in order to figure out when you can plant catharanthus.

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 require warm weather which tells us that you need to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant catharanthus in Louisville 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. You probably don't want to wait any later than that or else your catharanthus may not have a chance to fully mature. If you are starting your catharanthus indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Louisville the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of 0°F.

Remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Louisville and it can change quite a bit from year to year. Half of the time in Louisville you get surprised by a frost after April 15 so be sure to be ready to cover your catharanthus if you have a late frost.

USDA Zone Info for Louisville

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Louisville

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