One of the first steps you take when you are making a decision about your gardening schedule is find your 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 possible to determine when you can plant dahlias by referring to the USDA zone info for Oregon City.

Planting Calendar for Dahlias

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

Since dahlias require warm weather you really should wait until after the last frost before you can plant them.

The earliest that you can plant dahlias in Oregon City 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. If you wait any later than that and your dahlias may not have a chance to really do well. If you are starting your dahlias indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is March 15 in Oregon City. It might get as low as 15°F during the coldest months of winter.

Since the USDA zone info for Oregon City may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in Oregon City there is a last frost after March 15 be ready to cover your dahlias if you have a surprise late frost.

USDA Zone Info for Oregon City

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 Oregon City

You may be interested in your other planting guides for Oregon City.