Roots won't dry well if at all in the sixties. I have lots of trouble drying roots in the fall because of cool conditions. I actually dehydrate a lot of my roots in a unit I built. I use an old up right freezer with compartment doors on it and one main door. I built drying racks in it so I could use a 75 to 100 watt light bulb to put warm air in the unit. I put my bulb in the very bottom of the freezer and clsoe all the compartment doors and close the main freezer door to where it has about an inch crack in the door. This lets humidity out of the unit.
Now if I have larger amts. of roots to dry , say 30 -40 lbs of roots , I either put them on screens in a wooden outbuilding that is a 10x16 and close the doors and turn on a fan. Or I put them on tarps outside and let them be in kind of a little shade and a little sun. If you do it that away, be sure to never let it rain on your roots and be sure and bring your roots in at the end of the day. Dew will make your roots look bad.
Never dry your roots in a microwave nor a conventional oven on your stove. To have success you pretty much have got to follow my steps fairly close, unless your lucky.
Always something to worry with , is that not right? Just like fur, ifin you don't know how to do the process, you can sure mess up a bunch of money.
You can also use wood heat in a building and put air on your roots. Have the roots on racks with the air circulating through the building. I like the temps to be no less than 80 and no hotter than 100 and even at 100 it is a little warm. Actually I think best conditions are from about 85 to 95.
Roots won't dry well in a damp basement or a cool basement.

Can they be dried in a regular food dehydrator, don?

yes, certain roots can be...like bloodroot, cranesbill and ginseng.......but other roots i'd say no...like joe pye, poke root etc.........simply because the size prohibits it due to the roots being much larger..

Poke root must be sliced into smaller pieces to dry.

thanks don,i pmed ya for specifics as i have lots of poke.dont know how big the roots are but they grow every year in the same place.and this time of yr they are 8-10 ft tall and stalks bigger than a hoe handle.i know nothing about roots but want to learn.THANKS FOR YOUR TIME

Got a picture of the poke plant? What do you do with the roots? Is there a market for them?

In the fall of the year when temps start dropping I wonder if the dry attic of my house would work? I have an automatic thermostat to control the temperature from becoming too high. It's very dry and ventilated, the temperature normally stays in the 80's in my attic through November. Now you've got me thinking...Anyone ever tried an attic for drying roots or dehydrating?
Thanks Don!

I have some fellas that sell to me that dry roots in attics. Like anything else, if you do start them in the attic, just do a lb. or so first to see how well they dry. Roots should not lay around for several days and show no sighn of drying whatsoever. If you have the correct conditions, most roots in good warm drying conditions should be mostly dry or well on their way in a week if you don't pile them up to much. Root drying is an art that you must learn and learn it well. It is not to hard to do if you pay attention.

Thank you Don, I'm going to try it and I will either let you know how it goes or post pictures of the process and have you take a look and offer your advice. I'm here to learn so please don't hold back with constructive comments.

Poke is utilized in the Herbal Medicine Industry as a lymphatic cleanser and Cancer Therapy. It is toxic so a qualified practitioner is recommended before using. There isnt a huge demand in herbal manufacturing and it grows abundantly so the price it fetches isnt exceptional, but there are buyers.