When to Plant Dahlias in Cottage Grove, OR

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

One way of getting a good idea when to plant dahlias is to use the USDA zone info for Cottage Grove.


Planting Calendar for Dahlias

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

Dahlias do not do well in cold weather which means that you really should wait until it warms up after the last frost before you can plant them.

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 Cottage Grove 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. You probably don't want to wait any later than that or else your dahlias may not have a chance to fully mature. Starting your dahlias indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on March 15 in Cottage Grove. In the coldest months of winter you can expect an average low temperature of 15°F.

Always keep in mind that USDA zone info for Cottage Grove is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Cottage Grove you get a frost after March 15 be ready to cover your dahlias if you have one of those late frosts.

USDA Zone Info for Cottage Grove

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 Cottage Grove

You may be interested in your other planting guides for Cottage Grove.