One of the best tools that you have as gardeners to help us estimate 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.

It's a good idea to determine when it's possible to plant argyranthemum by checking out the USDA zone info for Washington.

Planting Calendar for Argyranthemum

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

It's probably not a good idea to plant argyranthemum until after the last frost when the weather gets warmer because they do not do well in cold weather.

The earliest that you can plant argyranthemum in Washington 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 argyranthemum and expect a good harvest is probably August. If you wait any later than that and your argyranthemum may not have a chance to grow to maturity. If you are starting your argyranthemum indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost has passed is on March 15 in Washington. In the coldest months of winter you can expect an average low temperature of 10°F.

Keep in mind that USDA zone info for Washington 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 Washington you get surprised by a frost after March 15 so be sure to be ready to protect your argyranthemum if you have one of those late frosts.

USDA Zone Info for Washington

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 Washington

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