One of the best tools that you have as gardeners to help us estimate 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 figure out when it's the best time to plant catharanthus by reviewing the USDA zone info for Round Lake.

Planting Calendar for Catharanthus

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

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

The earliest that you can plant catharanthus in Round Lake 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. If you wait any later than that and your catharanthus may not have a chance to really do well. You can get started a little bit earlier by starting your catharanthus indoors.

Last Frost Date

The average date of last frost is April 15 in Round Lake. It might get as low as -15°F during the coldest months of winter.

Keep in mind that USDA zone info for Round Lake is an average and the actual date of last frost will vary from year to year. Since half of the time in Round Lake last frost occurs after April 15 be ready to protect your catharanthus if you have a late frost.

USDA Zone Info for Round Lake

Here is the info for USDA Zone 5b.

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

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

Plants to Grow in Round Lake

You may be interested in your other planting guides for Round Lake.