Before planting it is a good idea to find your USDA Zone info to figure out 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.

A way of figuring out when you can plant catharanthus is to use the USDA zone info for Thomson.

Planting Calendar for Catharanthus

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

You really shouldn't plant catharanthus until after the last frost because they are not cold tolerant.

The earliest that you can plant catharanthus in Thomson 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. Starting your catharanthus indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is March 15 in Thomson. You can expect an average low temperature of 10°F in the coldest months of winter.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Thomson and it can change quite a bit from year to year. Since half of the time in Thomson you get surprised by a frost after March 15 be ready to protect your catharanthus if you have a surprise late frost.

USDA Zone Info for Thomson

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Thomson

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