The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Gresham should be reffered to in order to figure out when to plant dahlia.

Planting Calendar for Dahlia

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

It's probably not a good idea to plant dahlia until after the last frost has passed because they do not do well in cold weather.

The earliest that you can plant dahlia in Gresham 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 dahlia and expect a good harvest is probably August. Any later than that and your dahlia may not have a chance to really do well. You can get started a few weeks earlier by starting your dahlia indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on March 15 in Gresham. It might get as low as 15°F during the coldest months of winter.

Since the USDA zone info for Gresham is an average the actual date of last frost will vary from year to year. Since half of the time in Gresham you get surprised by a frost after March 15 be ready to cover your dahlia in the event of a late frost.

USDA Zone Info for Gresham

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 Gresham

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