Tips and Tools on Overwintering Dahlia Tubers in Storage

dahlias

Oct 1

In this blog post I will cover:

How to Store Dahlia Tubers (review from Tips & Tools for Dividing & Storing Dahlia Tubers)
Temperature Control for Overwintering Dahlia Tubers
Humidity Control for Overwintering Dahlia Tubers
Devices for Monitoring Temperature and Humidity for Overwintering Dahlia Tubers

To Store Dahlia Tubers

I am trying something different this year: the Bloomquist method of dahlia tuber storage. The tubers go into plastic grocery bags and to which we added an equal measure of cedar shavings.

We don’t tie up the bags, this is important. We attach the variety’s name tag to the bag with our clothespin (see Tips and Tools for Cleaning and Storing Dahlia Tubers blog-post) and line the bags up in these cool collapsable bins. I alphabetize them at this point. Of course I do.

Dahlia Tubers in Cedar Chips in Plastic Bags in Crates

The bins then get stacked in a basement or outbuilding that will be cool, but won’t freeze. Below 50 and above 32 is ideal and we shoot for humidity of 75%-85%. I use a variety of devices to control the heat and humidity in the storage areas.

Temperature Control for Overwintering Dahlia Tubers in Storage

This time of year I worry about them getting cold (lows at 19, highs at 34), so I have a thermocube into which I plug an oil-filled space heater. Thermocubes are amazing, they turn on when the temperature approaches 32 and turn off when it approaches 45.

Make sure your oil-filled space heater has manual, not digital controls. Remember it is not going to have consistent power and one with digital controls may not come on when the power is flowing again. Today, Amazon has a 10% off coupon on this heater.

Humidity Control for Overwintering Dahlia Tubers in Storage

Dahlia tubers store best at 75%-85%. Humidity Control can be simpler or trickier depending on your situation. I store in two places, the building attached to my chicken runs and my inner basement. Tubers waiting to be divided are in the out-building and tubers that have been divided are in the basement.

In the Out-Building, which has the thermocube/space heater set up mentioned above, I just fill a pan with water and set it near the heater and that has been enough.

In the basement it is much dryer, as it gets some heat from the central heating. Here I use an Inkbird Humidity Controller. It is designed to have a humidifier and a dehumidifier plugged into it. It is easy to program it to turn the humidifier on if it is too dry and the dehumidifier on if it is to wet.

Again, make sure you get ones with manual, not digital controls.

Devices for Monitoring Temperature and Humidity for Overwintering Dahlia Tubers

So I get all these set up, but it is not enough, I have to be able to check on temperature and humidity from afar. I use a variety of devices, depending on how far the area I am monitoring is from the wifi router.

First up are the Govee temperature and humidity monitors. I can check the data in person, when I walk in to theoom or from my phone. I also have it set up to alert my phone if numbers are too high or too low. These work great in the basement — close to router — but not in the outbuilding as it is too far from the wifi signal. Right now, Amazon has a $5 off coupon on these.

In the outbuilding I use TempStick. It’s pricier, but it is able to latch on to wifi even out there. I also appreciate that it is a small business and the device is Made in America. Again, I can set it up to alert my phone if numbers are too high or too low.