When to Plant Dahlias in Sandy, OR

One of the first steps you take when you are determining 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.

One way of estimating when it's a good idea to plant dahlias is to consult the USDA zone info for Sandy.


Planting Calendar for Dahlias

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

You should not plant dahlias until after the last frost when the weather gets warmer because they do not do well in cold weather.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant dahlias
Possibly ok, but a risky time to plant dahlias
Probably not a good time to plant dahlias

The earliest that you can plant dahlias in Sandy 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 fully mature. If you are starting your dahlias indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Sandy the average date of last frost happens on March 15. It might get as low as 15°F during the coldest months of winter.

Always keep in mind that USDA zone info for Sandy may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in Sandy you get a frost after March 15 so make sure that you are ready to protect your dahlias if you have one of those late frosts.

USDA Zone Info for Sandy

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 Low15°F
Highest Expected Low20°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 Sandy

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