Saving Dahlia Tubers in Pots

Step 1: Wrap the pot in bubble wrap.

A year ago I dug up my dahlia tubers and kept them all winter long in town in my spare condo bathtub. The tubers were hard to dig up, and needed added moisture in their protective sacks ever few weeks. Most of them did survive for replanting.

Step 2: In fall cut back to a few inches.

Last summer the dahlias gave me beautiful flowers, but I wanted an easier way to save them.

So last year I tried keeping the the tubers in their pots. We don't get extreme cold, but we do have freezing nights, and several stretches of freezing weather.

Step 3: Crumple newspaper over the soil.

I started by wrapping the pots in bubble wrap I purchased at the Dollar Store. Each pot got $2 worth of bubble wrap held in place by duct tape. My thinking is that the air pockets will help keep the freezing air away from the sides of the pot, much like an insulated water pipe.

Step 4: Place cardboard over the newspaper.

When the weather started turning cold, I cut the dahlia plants back. I crumpled newspaper over the soil to give the tubers an insulation barrier. Over the top of the newspaper I put a layer of cardboard, and topped it off with soil to keep everything in place on windy days.

Step 5: Cover with a thin layer of soil.

I don't have any place to bring the pots indoors at the cabin where temperatures won't get below freezing sometime during the winter.

Have you ever kept dahlias outdoors through the winter? Do you get freezing nights? Was it successful for you?

Dahlia tubers in pots ready for winter.

My overwintering experiment was a huge success. Here are the results for my two pots.

Pot #1

Pot #2

The bubble wrap is still on the pots and ready to go for next winter. All I have to do is cover the tops again for next winter. This was so much easier than digging up all the tubers and storing them in my bathtub. -- Margy

Saving Dahlia Tubers

I've purchased Dahlia tubers for years to plant in my flower pots. Last year I left the tubers (thickened underground stems that send out roots) in the ground. They rotted. This year I'm digging them up and to save over the winter.


Digging up my dahlia tubers:

I waited until November and our first frost to dig up my dahlias.

I trimmed the plants back to three inches of stalk. They were really hard to dig out of my pots, so I loosened the dirt around the edges and worked my trowel underneath to lift the tubers out as carefully as possible.

I let the tubers dry on the surface for a day, and then transferred them to the picnic table to dry for another two days. By then, the soil was dry and easy to brush off. I was amazed how many new tubers were in each cluster.

I used scissors to clip off the feeder roots and secondary tubers coming off the main tubers. Check out Bren W's YouTube video.

I chose not to divide my tubers. Each pot gave me two tuber clusters.

Storing my dahlia tubers over winter:

I placed my cleaned tubers in paper bags for storage. I didn't have peat moss, but had a bag of potting mix.

The clean soil keeps the tubers moist so they won't dry out. The video below recommends periodic checking. If the soil gets too dry, give it a light mist with water. Don't get it overly wet or the tubers may rot.

They recommend a dark cool spot like a crawl space or root cellar that will not freeze.  That leaves my cabin out. I chose my spare bathroom in the tub next to my geraniums.

The guides say to keep them at no higher than 50 degrees or the tubers may rot or sprout too early. We keep our condo heaters on low (10 degrees centigrade/50 degrees Fahrenheit) to prevent the pipes from freezing. Sounded perfect.

Here's a YouTube video by Longfield Gardens I used to learn what to do.

I'll let you know how it turns out. - Margy

Dividing Rhubarb Plants

I've grown rhubarb in a medium sized container since 2010.

It started from bare-root stock and has provided me with enough stalks each year to make several pies and crisps.

I knew my plant was becoming pot bound due to visible splits in the plastic container, and the reduced production in larger stalks.

I researched online and watched YouTube videos about how to divide and replant rhubarb.

The root mass removed from the pot.

I waited for fall when the plant became dormant.

It was so pot bound it took me a long time and lots of digging to loosen it from the container.

You can see what a tight mass the roots had formed.

Using a serrated knife to cut the roots.

There was no evident division point in the plant, so I decided to cut it right down the middle.

Large roots sliced through.

The slice exposed very large roots cut right through the middle.

I worried that the "wounded" roots might die or become diseased, but that didn't happen.

I used a larger pot and placed both sections in with plenty of spreading room in between.

The two halves get a larger pot.

I made sure the plant crowns were even with the top level of the soil.

I used fresh potting mix to fill in the empty spaces between and around the the roots.

To protect my plants from the coming winter's freezing temperatures, I covered the top of the pot with crumpled newspaper, cardboard and an inch of soil.

Removing the winter covering.

Here's a post of a similar process I used with my dahlia tubers.

When spring arrived, I removed the covering to expose the budding shoots.

I'm happy to report that both sides have not only survived, but are thriving.

I can hardly wait for my first crop to make a strawberry, apple, and rhubarb crisp. -- Margy

Black Vine Weevil Carboard Trap

An "Evil Weevil" from my float garden.

When I cut down my daffodils, I uncovered a cluster of beetles on the ground. The oval shape with a pointed snout made we immediately guess weevil.

I did some research and believe they are Black Vine Weevils. I also discovered the small white legless grubs with orangish heads I found in an old dahlia pot are the larval form of these weevils. It's the grubs that cause the greatest harm in the garden by eating roots. 

Tap cardboard traps on the ground to dislodge hiding weevils.

Known as the "Evil Weevil" in the gardening world, now is a good time to eradicate them is before they lay eggs. One adult can lay 500 eggs, and because they are capable of parthenogenesis (eggs don't require fertilization to mature) they are very prolific.

Make a cardboard trap.

I decided to use a manual approach. The beetles are nocturnal eaters, and hide during the day. Look for scalloped edges on leaves to find them.

Use a flashlight at night to pick the slow moving beetles off plants and drop them into soapy water.

Strip off one side of the cardboard.

Or during the day, explore shady spots under plants.

Rather than soapy water, I turn the weevils into fish food by flicking them into the lake next to my floating garden.

I read about cardboard traps and gave them a try.

Tape into a tube, cover if needed.

I stripped off one side of cardboard to reveal the corrugated interior. I cut and rolled it into a tube with the rippled side inward. Because we get lots of rain, I covered the outside with duck tape to protect the cardboard.

The first night I caught three weevils in my trap. With that success, I'll make some more. 

Do you have Evil Weevils in your garden? What do you do to get rid of them? -- Margy