One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The best time to plant catharanthus in Rocky River can be figured out by using the USDA zone info.

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 are not cold tolerant you need to wait until after the last frost has passed before you can plant them.

The earliest that you can plant catharanthus in Rocky River 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 little bit earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Rocky River. You should expect an average low temperature of -5°F in the coldest months of winter.

Keep in mind that USDA zone info for Rocky River is an average and the actual date of last frost is different every year. Half of the time in Rocky River last frost occurs after April 15 so always be ready to protect your catharanthus in the event of one of those late frosts.

USDA Zone Info for Rocky River

Here is the info for USDA Zone 6b.

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

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

Plants to Grow in Rocky River

You may be interested in your other planting guides for Rocky River.