One of the first steps you take when you are getting a good idea 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.

The earliest that you can plant pentas in Washington can be figured out by using the USDA zone info.

Planting Calendar for Pentas

Frost tolerance for pentas:	Not tolerant of frost.
When to plant:	After the last frost has passed.

It's a bad idea to plant pentas until after all chance of frost has passed because they require warm weather.

The earliest that you can plant pentas 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 pentas and expect a good harvest is probably August. Any later than that and your pentas may not have a chance to really do well. Starting your pentas indoors is a great way to get them started a few weeks earlier.

Last Frost Date

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

Always keep in mind that USDA zone info for Washington may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Washington there is a last frost after March 15 so just be sure to be ready to cover your pentas in the event of a late frost.

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.