One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can determine when it's a good idea to plant catharanthus in Williams by using the USDA zone info.

Planting Calendar for Catharanthus

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

You really shouldn't plant catharanthus until after the last frost because they do not do well in cold weather.

The earliest that you can plant catharanthus in Williams is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant catharanthus and expect a good harvest is probably September. 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 few weeks earlier.

Last Frost Date

In Williams the average date of last frost happens on February 15. In the coldest months of winter you can expect an average low temperature of 25°F.

Just be sure to remember that USDA zone info for Williams may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Williams it frosts late in the year after February 15 so always be ready to protect your catharanthus in the event of one of those late frosts.

USDA Zone Info for Williams

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°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 30°F.

Plants to Grow in Williams

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