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.

In Idaho Falls you can figure out when to plant catharanthus 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.

Since catharanthus do not do well in cold weather it's necessary to wait until after the last frost has passed before you can plant them.

The earliest that you can plant catharanthus in Idaho Falls 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 fully mature. 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 Idaho Falls. In the coldest months of winter you can expect an average low temperature of -20°F.

Since the USDA zone info for Idaho Falls is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Idaho Falls it frosts late in the year after April 15 be ready to protect your catharanthus if you have one of those late frosts.

USDA Zone Info for Idaho Falls

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Idaho Falls

You may be interested in your other planting guides for Idaho Falls.