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Open-centered dahlias, a pollinator favorite

Trying to find plants that bloom in summer and fall can be a challenge. Not only do the honey bees have trouble finding forage, but even the native bees can come up short during the summer dearth. This is especially true in areas where native plants have largely been replaced with exotic species.

Last fall, Ellen Gehling, a beekeeper living here in Washington state, offered to send me a selection of open-centered dahlias which her bees love. I’ve never been a fan of big showy dahlias that look like garish dinner plates, but I had heard from other beekeepers that the simple, open-centered varieties were bee favorites. So “Yes!” I said. I was eager to try.

Tubers in the mail

Ellen sent a well-packed and labeled box of tubers along with detailed instructions about planting and growing. My husband built a raised bed just for the project, and I planted according to the instructions. Now, in the heat of August, I have a gorgeous display of flowers that the pollinators love. Not just bees, but also hover flies, skippers, and some solitary wasps have descended on the blooms. In fact, so many pollinators visit that the crab spiders have staked out their territory as well, taking advantage of anyone not paying attention.

For pollinators, the difference in dahlias has to do with the central disk. The central disk is where the pollen is produced and where the bees can access the nectar. Highly bred dahlias can have so many layers of florets that the pollinators cannot even find the central disk. Those varieties are of no interest to pollinators and are left alone in the garden.

I’m grateful to Ellen for showing me a new way to look at dahlias. Without her guidance and generosity, I would not have considered dahlias for my pollinator garden. Now they will be a regular feature.

Rusty
Honey Bee Suite

Dahlia with central disk.
In this photo you can clearly see the central disk that is all-important to the pollinators. © Rusty Burlew.
Dahlia-4
Here a bumble bee, probably a male Bombus vosnesenskii, is sampling a flower.
Male bumble bee
This is also a male bumble bee. The bumbles were quite taken with these flowers, and some of the males are sleeping in them overnight. © Rusty Burlew.
Dahlia with skipper
This woodland skipper, a type of butterfly, is sampling the dahlias. © Rusty Burlew.
Dinner of various types
Lots of drama here. One bumble bee is eating dinner, while the other is dinner. Note the camouflage coloring of the crab spider. © Rusty Burlew.
Crab spider
It is easy to see why the crab spiders are so well fed. © Rusty Burlew.

Comments

Anna
Reply

I have a dahlia garden behind my hives and have also enjoyed seeing the variety of pollinators that visit the flowers, including bees I still don’t know the names of. I will make sure to add more open centered ones next year. These are some great photos! Thanks for sharing!

Ken Rhodes
Reply

My neighbor has every year planted a two foot wide row half a city lot long of Zinnias which the pollinators love, including my honey bees. These will bloom until a heavy frost providing pollin during the late summer.
Ken

John O'Neill
Reply

What varieties were the best?

Rusty
Reply

John,

You are not supposed to ask that! If Ellen knew that I got her carefully made labels and marked tubers all tangled up, I would be in serious trouble.

Marilyn
Reply

I’ve planted collarette dahlias for years, and yes the bees love them! You can mail order from Dahlias.com in Canby, Oregon. Also, I planted cosmos in my garden for the first time this year and they are by far the favorite with bumble bees.

Tom
Reply

Did a Google search for open-centered dahlia tubers to buy but no luck. Any idea where to buy them? Thanks

Rusty
Reply

Tom,

See comments for a place in Oregon. Also, you can ask Ellen at ellenmgehling@gmail.com. She said she will answer questions.

Bill Castro
Reply

Rusty,

The 2 most awesome plants for late summer are heptacoduim, hasn’t bloomed yet, and ajania pacifica. Both are top notch bloomers that all pollinators, especially honeybees, abosolutely adore!!!! I will also mention that the dreaded climbing ivy is a miracle worker that provides abundant nectar and pollen in mid September for well over a week. These plants will turn a weak colony into a winter survivor!!!

Bill Castro

Rusty
Reply

Bill,

Ivy honey has always intrigued me. I often hear of it, never seen it.

Ellen
Reply

Hi Rusty,
The funny thing is that I see from your pictures that I had mislabeled one too! I don’t know what your observations are, and I haven’t considered it too carefully but it does seem that some varieties are visited more than others, and some more floriferous, which may be more desirable to someone wanting to plant them for pollinators.

As always, your photos are fantastic, and I particularly like the dramatic one; two bumble bee species and one spider on a single bloom. I’ve also seen a Red Admiral butterfly and honey bee foraging on the same blossom.

I thoroughly enjoy these colorful flowers, and I’m pleased that you and your invertebrate friends are enjoying them too. I don’t know what your policy is on this, but if anyone wants more information about open centered dahlias, they are welcome to contact me through email.

Rusty
Reply

Thanks, Ellen. I will let people know. Saw leafcutters on them today…photos coming!

Kris
Reply

Try Cleome (Spider Flower) for the honey bees. They love it and the plant gives one a plethora of seeds for the next season if collected. Orjust let the seed fall to the ground for the next spring germination.

Anne Fifer
Reply

I’m glad you posted about these. Awesome photos, too!

Glen Buschmann
Reply

Just placed an order for some open-centered dahlia seeds (and some cosmos too). I’ll keep you informed.

Feb 2017
vbbbGlen

Rusty
Reply

Pictures too, Glen. I want to see pictures!

Pat
Reply

My wife wondered what caused the circular holes in the Black-eyed Susans and Knockout Dahlias. It was the leafcutter bees.

Here’s a video of a leafcutter bee in action on both flowers…

http://www.youtube.com/watch?v=sDrRoyEyaz8

Rusty
Reply

Pat,

Great video. It’s like they have scissors.

Pat
Reply

Here’s a video of a crab spider just missing a tasty bee snack (at 1:14)

Rusty
Reply

Pat,

Oops. No link.

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