That’s the question, folks.
The little bas…the darling pet runs about unsupervised sometimes and likes to dig. A lot. Very quickly.
Thermonuclear weapons may not be considered.
There is only one way - bye-bye house plants.
Well maybe you could just have hanging house plants with nothing around for the little darlings to fling themselves from?
Keeping ferrets out of anything they want to be in is virtually impossible.
My cat would not stop digging in my house plants. I went to a home improvement store and bought a few of those large flat stepping stones. I dropped the stones so they broke into large chucks. I took the large chunks and placed them over the soil. The gaps between the stones were too small for the cat to dig in and the stones were too heavy for her to move them. I hopes this works.
Alternatively, try some heavy-duty screen/mesh over the soil? Edges could be bent over the pot’s rims and tied/taped down.
I believe a combination of the last two is excellent.
Thank you, ladies and gentlemen.
The little bas…beloved pet thanks you, too. Or rather, he should. He lives to disgrace himself under furniture and pile up stolen dog food in secret caches. 
While I’ve got you here…
What do you think of ferret balls? No, the big hamster ball thingies?
While searching for them on the web, I discovered that some folks believe them to be horrible instruments of torture. My family, who may receive one for Channukah/Christmas think they are cool. I’ll keep the stairway door closed.
Good luck with it. Hope you post pictures when you get the change… 
One of the problems with the small animal balls is the hamster/ferret will pee and poo in the ball and then they roll it all over them while running around and you end up with a very smelly pet.
Moses and Aaron on a stick, this is a FERRET.
Plants with big nasty spikes?
I agree with the no house plants anymore. I used to do the screen and/or rocks in the pots, my cats always defeated them.
If I could find a big enough ball to put kittens in, I’d so do it.
THIS fine young man has the right idea.
My ferrets never seemed thrilled with the ferret balls. I think it was because they weren’t scaled right - their long tails always trailed behind and angled up in the ball, and it seemed uncomfortable or something. Hamster balls are much larger proportionally; it’s easier for the hamster to run in those things.
I’ll have to regrettably file that one as “Harmful to furniture and other pets”.
I agree with others…
- Ferrets
- House plants
choose one.
I used to have a very nice spider plant named Simon. I used to have a ferret named Bandit. Bandit murdered Simon. I learned to forgo houseplants after that.
As for ferret balls, they’re kind of amusing for short periods of time (ours put up with them for about 30 minutes at a time), but you can’t seriously intend to only have the ferret out in one of those. Don’t even try it. You need to keep a close eye on them, and that’s all there is to it. They can’t be unsupervised like a dog or a cat, and I promise that even in a ferret ball they’ll get into trouble if no one is watch them.
Cut wire mesh to the shape of the pots but 3-4" bigger, cut a slit in one part of the circle and cut out a space in the middle that fits the plant in question, fit it around the plant and flatten it to the top of the pot, then bend the edges down around the rim of the pot to hold it on. It looks much better if you cut some the wire around the rim and fold it down in sections. Clear as mud?
I have some big houseplants and a small cat who likes to shit in them, this works great for me. Though it doesn’t look exactly pretty.
I would think the OP’s username would suggest a rather simple and final solution…
Yeah, right.
Mrs. Plant asks, “Honey, have you seen the ferret? Why is your trap so full?”
He is rather rat like, though…
Do you have a dog as well which the ferret is stealing from, or are you feeding your ferret dog food? If the latter, please consider switching to ferret food, or at least kitten food. Dog food (and cat food) doesn’t have enough protein for ferrets.