They DO love a ripe tomato and tender young plants If you have a way to pen those off, it can help. But, many things they don't mess with and not everyone uses mulch. It is a consideration. For me, it's after garden is well matured.
Many years ago I had a garden, fenced, and a flock of free range chickens. There were about a dozen young roosters who decided to fly into the garden. They scratched up several of my young tomato plants. Ran them out, moved them to another area and replanted. Couple days later, got my plants again. That night I caught them all, caged them & following morn...butchered. Don't mess with my tomato PLANTS!!
Since then, I'm not wanting them in there until plants get established. I can deal with a couple tomatoes -- not all the plants. They do tend to like to scratch at the base of the plants and any area you have seedlings you know they will kill them all.
I have all raised beds, with a 4 foot post at each end and a ridge pole across the top. I can put frost cloth over the bed to extend the season, or bird netting to keep birds out of the crops, shade cloth to keep spring greens from bolting so fast, etc or create a trellis for the climbers. I haven't let the chickens into the garden itself, but they roam all around it and get a lot of the bugs that are trying to move in. I may have to let them in to keep the grasshoppers down though... even Neem Oil hasn't done more than just slow down the damage a bit. Our season is so short, that the only time I can see to let them in while protecting our main crop - especially the tomatoes and squashes, would be AFTER the first freeze.
Britesea, you have a perfect set up for keeping them off of plants they want to invade....just made a few panels of fence that are from edge of bed to crosspole and lean them up there. They don't always eat it. EXCEPT blueberries. LOL Watched them jump and pick mine! No wonder I wasn't getting any
Some plants they don't want. So protect others. Could work a few hours, couple times a week and help you out. Mine love to jump in their high grass and catch hoppers. Fun to watch. Sometimes I throw a little scratch feed along a building so they scratch the grass/weed up.
DH and his family used to do a 3 year rotation with the garden. They had 3 30x30 plots side by side. Year 1- Garden in plot 1, Pigs in plot 2, Plot 3 was covered with compostables of all types, allowing the chickens free run. Year 2- Pigs in plot 1, plot 2 compost, plot 3- garden. Year 3- Compost in plot 1, garden in plot 2, pigs in plot 3. Rinse and repeat. In the spring, they just went out there and scraped back the top layer of compost and dropped the seeds in (jump back or it'll hit you in the eye!). After almost 30 years of doing this, the soil was absolutely amazing. If I could have afforded a couple of dump trucks to haul it up to Oregon when we moved, I would have!
@milkmansdaughter I will look to see if I have some pictures. @Mini Horses I have some leftover 1" chicken wire mesh that I might be able to use like you suggest. I can even see that being good under the frost cloth to hold it up a little better...