Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By looking at the USDA zone info for Scappoose it's a good idea to figure out when you can plant dahlias.

Planting Calendar for Dahlias

Frost tolerance for dahlias:	Not tolerant of frost.
When to plant:	After the last frost.

It's probably not a good idea to plant dahlias until after all chance of frost has passed because they require warm weather.

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

Last Frost Date

In Scappoose 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.

Remember that USDA zone info for Scappoose is an average and the actual date of last frost will vary from year to year. Half of the time in Scappoose there is a last frost after March 15 so make sure that you are ready to protect your dahlias if you have a surprise late frost.

USDA Zone Info for Scappoose

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 Scappoose

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