Chickens ruining flower beds
Unfortunately pecking at the soil is what chickens are programmed to do and it is what they spend most of the day doing. Chickens and nice gardens don’t exactly go hand in hand. Other than wire fencing off the beds and physically separating the parts of the garden where you want plants to grow and chickens to roam with fences, screens and gates, the options are pretty limited.
I have four chickens at home and we have built them a fair sized chicken run which is separate from the rest of my garden to spare my precious plants. They can roam around and are free to dig holes and create as much havoc as they wish in their own space and I also have the peace of mind that they are safe from foxes too. We live in a small town and lost our first batch to foxes so the chicken run is now fully fox proofed (fingers crossed) and I would seriously recommend that you do the same.
The suggestion you had of putting a layer of netting or wire under the bark chippings in my opinion would be a waste of time and money because they would just peck through it.
Harrod Horticultural sells various cages and products which you may be interested in. Aluminium Chicken/Poultry Cages, Heavy Duty Steel Chicken & Poultry Cage or Heavy Duty Chicken Wire Fencing to build your own run if you have room and decide to go down that route. Heavy Duty Roof Netting is available too, this will secure your run against foxes. If you decide against that option Slot & Lock Low level strawberry /vegetable cages are good for moving around and would offer protection to your plants.
Depending on what kind of plants you are growing in your garden chickens can benefit the garden by eating grubs, larvae and insects, aerating the soil and of course fertilising the beds and if the new planting is predominantly annuals, perennials and deciduous specimens, then it’s actually a very good idea to let them scratch around all winter if you are prepared to tidy up after them! I let my chucks out sometimes when I’m gardening in that area but I do have to clean up after they have kicked back soil everywhere.
I hope that this helps and gives you some ideas to go forward with, please don’t hesitate to call the office if you need any help or advice with products or ordering.