One of the best tools that you have as gardeners to help us determine 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 Washington you can determine when it's a good idea to plant dianthus by referring to the USDA zone info.

Planting Calendar for Dianthus

Frost tolerance for dianthus:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since dianthus do well in moderate cold you can plant them a bit earlier in the year than other frost tender plants.

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

The last month that you can plant dianthus and expect a good harvest is probably September. If you wait any later than that and your dianthus may not have a chance to grow to maturity. Starting your dianthus indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Washington the average date of last frost happens on April 15. You should expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for Washington is not always accurate the actual date of last frost is different every year. Since half of the time in Washington it frosts late in the year after April 15 be ready to cover your dianthus in the event of one of those late frosts.

USDA Zone Info for Washington

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°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 -5°F.

Plants to Grow in Washington

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