When to Plant Dahlia in Monmouth, IL

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.

You can figure out when it's a good idea to plant dahlia in Monmouth by using 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.

Dahlia are not cold tolerant which means that you have to wait until it warms up after all chance of frost has passed 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. You probably don't want to wait any later than that or else your dahlia may not have a chance to fully mature. If you are starting your dahlia indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Monmouth the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -15°F.

Keep in mind that USDA zone info for Monmouth is not always accurate and the actual date of last frost is different every year. Since half of the time in Monmouth it frosts late in the year after April 15 be ready to cover your dahlia if you have a surprise late frost.

USDA Zone Info for Monmouth

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-15°F
Highest Expected Low-10°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 -10°F.

Plants to Grow in Monmouth

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