One of the first steps you take when you are figuring out 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 will be able to estimate when it's the best time to plant catharanthus by using the USDA zone info for Kirkland.

Planting Calendar for Catharanthus

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

Since catharanthus do not do well in cold weather you must wait until after the last frost has passed before you can plant them.

The earliest that you can plant catharanthus in Kirkland 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 grow to maturity. You can get started a little bit earlier by starting your catharanthus indoors.

Last Frost Date

The average date of last frost is March 15 in Kirkland. In the coldest months of winter you can expect an average low temperature of 15°F.

Since the USDA zone info for Kirkland may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in Kirkland it frosts late in the year after March 15 so just be sure to be ready to protect your catharanthus if you have one of those late frosts.

USDA Zone Info for Kirkland

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

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

Plants to Grow in Kirkland

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