The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By reviewing the USDA zone info for Happy Valley you should be able to figure out when it's a good idea to plant bidens.

Planting Calendar for Bidens

Frost tolerance for bidens:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

It's a bad idea to plant bidens until after the last frost because they are not cold tolerant.

The earliest that you can plant bidens in Happy Valley 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 bidens and expect a good harvest is probably August. You probably don't want to wait any later than that or else your bidens may not have a chance to grow to maturity. Starting your bidens indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Happy Valley the average date of last frost happens on March 15. You can expect an average low temperature of 15°F in the coldest months of winter.

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Happy Valley and it can change quite a bit from year to year. Half of the time in Happy Valley you get surprised by a frost after March 15 so make sure that you are ready to cover your bidens in the event of a late frost.

USDA Zone Info for Happy Valley

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 Happy Valley

You may be interested in your other planting guides for Happy Valley.