Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You should be able to determine when to plant catharanthus by checking out the USDA zone info for Forest Lake.

Planting Calendar for Catharanthus

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

It's probably a bad idea to plant catharanthus until after the last frost because they require warm weather.

The earliest that you can plant catharanthus in Forest Lake is May. However, you really should wait until June 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 grow to maturity. If you are starting your catharanthus indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Forest Lake. It might get as low as -25°F during the coldest months of winter.

Since the USDA zone info for Forest Lake is just an average the actual date of last frost will vary from year to year. Half of the time in Forest Lake you get a frost after May 15 so always be ready to protect your catharanthus if you have a surprise late frost.

USDA Zone Info for Forest Lake

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Forest Lake

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