When to Plant Dahlia in Monmouth, OR

Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can figure out when you can plant dahlia in Monmouth by reviewing the USDA zone info.


Planting Calendar for Dahlia

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

Since dahlia do not do well in cold weather it is important to wait until after the last frost when the weather gets warmer before you can plant them.

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

The earliest that you can plant dahlia in Monmouth 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. If you wait any later than that and your dahlia may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your dahlia indoors.

Last Frost Date

The average date of last frost is March 15 in Monmouth. You should expect an average low temperature of 15°F in the coldest months of winter.

Since the USDA zone info for Monmouth is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Monmouth you get surprised by a frost after March 15 so make sure that you are ready to cover your dahlia in the event of a late frost.

USDA Zone Info for Monmouth

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 Monmouth

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