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.

You should be able to determine when it's the best time to plant catharanthus by reviewing the USDA zone info for Hays.

Planting Calendar for Catharanthus

Frost tolerance for catharanthus:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Catharanthus are not cold tolerant which means that you need to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant catharanthus in Hays 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 grow to maturity. If you are starting your catharanthus indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Hays. You can expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for Hays is an average the actual date of last frost changes from year to year. Since half of the time in Hays you get surprised by a frost after April 15 be ready to cover your catharanthus in the event of a late frost.

USDA Zone Info for Hays

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°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 -5°F.

Plants to Grow in Hays

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