Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The best time to plant catharanthus in The Dalles should be estimated by looking at the USDA zone info.

Planting Calendar for Catharanthus

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

Catharanthus are not cold tolerant which tells us that you need to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant catharanthus in The Dalles 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. You probably don't want to wait any later than that or else your catharanthus may not have a chance to fully mature. Starting your catharanthus indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on March 15 in The Dalles. It might get as low as 10°F during the coldest months of winter.

Since the USDA zone info for The Dalles is an average the actual date of last frost will vary from year to year. Half of the time in The Dalles last frost occurs after March 15 so be sure to be ready to protect your catharanthus if you have a surprise late frost.

USDA Zone Info for The Dalles

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 The Dalles

You may be interested in your other planting guides for The Dalles.