Bare weed barrier will last a long time if it’s good material. When covered with mulch, weeds will grow in the mulch and right through the barrier.
Adding mulch every year under the weed barrier is a lousy idea. Totally unworkable. Forget the weed barrier if you are going to put mulch on top or underneath every year.
You’ll never eliminate bindweed by weeding. But you can make it a non factor. And with mulch it becomes easier to weed.
How big of an area are we talking about?
Me, too! I used plastic because I became concerned about the build-up of organic mulch. The nurseryman I bought the trees from told me that I was being a ninny and that I should just pull the mulch away from the graft unions. Nowadays, however, replacing the plastic has become problematic with (my) advancing age. I’m thinking of seeding white clover and transplanting a (little) comfrey into the bare patches left behind. As I imagine it, the beauty of comfrey is that it can be cut back in dry weather leaving a natural moisture-conserving mulch that doesn’t build up. It’s immortal, so cutting doesn’t extirpate it.
You say plastic, is that weed barrier or poly?
Wow, you’re the first person that I’ve heard of doing that. I’ve been doing it for years, but thought I came up with the idea. I’ve heard a lot of negative comments about using cardboard, but it has worked for me. I have a large supply. I will make another post about the method I use
It’s black plastic sheeting only a mil or two thick. I’m not recommending this because I’m giving it up as too labor intensive. This stuff is fragile. The squirrels delight in digging through it to see what’s underneath. It’s light enough to blow away, so I have to pin down all edges. The pins tear through it, so I have to apply a patch of duct tape before inserting a pin. It’s a lot of trouble because I’m misusing the product. Here is how you’re supposed to do it:
I’ve been using this method for about the last four years. I have an abundant supply of cardboard what you call pallet covers 48 x 48“ most all the grocery stores get their canned goods on pallets with cardboard covers. I make a plastic ring with 2 wood screws to hold it in a circle. It’s I think 6 inch black border from Lowes. I don’t bury it. I have electric scissors I got from Harbor Freight and a razor knife. I do have gaps around the edge of the plastic and cardboard . I cut a circle around the tree with a razor knife, put in a screen around the base of the tree to hold the wood chips off of the trunk. Then pile the wood chips on the ground and the top of the cardboard I use no float mulch. I do it in late February and use a bedding fork to pick up the cardboard in December. It holds up well. I will pile a little dirt on the inside of the ring, just to hold it in place in case it gets hit by a mower. It takes me about 30 minutes per tree that includes fertilizing, compost, and manure, which I put down and wet before I put the cardboard on it . The biggest problem is ants around the edge of the cardboard and the black ring. They don’t get next to the tree. I try to control them with wood chips around the edge are natural sprays, but it is a struggle. I really like the way that it not only controls the weeds, but it’s perfect for droughts during the summer. The water will run from the edge of the black plastic down to the wood chips. I also water the wood chips around the tree directly . The water also runs underneath the cardboard.
That blocks the water. How can that be good for anything?
this isnt really a thing, right? mulch, wood chips, leaf litter doesnt really pose a threat to trees via mold/fungus/rot does it? nobody is protecting the trunks of trees in the wild. ive always figured this is one of those things that just keeps getting passed along 
I’ve tried planting stuff under my fruit trees, but invariably Himalayan blackberries and thistles love those conditions, and then I can’t mow as close to keep them in check for fear of destroying the planting.
One rosemary is about all I have left like that.
I also tend to agree here. Granted some things it could pose a threat potentially, but the threat is far overblown in my eyes.
A lot of gardening advice I’m sure has sound logic behind it, but much of it does not seem true in practice… Or at least it may be true in certain climates but not in others. But it gets spread around like it is gospel nonetheless.
I have had zero issues with wood chip rotting against a living trunk. Maybe if you are cutting open the bark accidentally with a grass trimmer it may cause infection but otherwise it seems OK even in my damp climate.
I am certainly a novice, so no argument here, but it takes so little effort and on the outside chance it might protect the trunk from crawlers worth the effort for me.
i guess that did sound like a jab and it wasnt meant to be. sorry. im the same and try to keep my trunks clean as well. was just wanting to bring it into conversation so the more experienced around here would weigh in on it as ive seen very few people say otherwise.
No offense taken. I like to expand the conversation that’s good for everyone.
I’ve heard that the main purpose of not putting mulch right up to the trunk is to keep mice from nesting there in the winter and chewing on the bark.
I spent a lot of time last year ripping up 1 to 15 year old weed barriers on family and friends gardens. The newer placed ones hadn’t visibly hurt the soil yet, but only weeds were growing over and under them and they were clearly poor quality because already falling apart. The old ones that were entirely intact…I have never seen such poor soil as under those. In some cases, the soil was pale green or grey. For all gardening purposes, I would avoid plastic barriers.
A slow growing thyme ground cover might manage in the dry conditions and be ok with part shade. I’m planning on planting some plugs around trees this fall along with things already mentioned in this thread. Oh and field pussytoes might work?
I’ve always followed that advice but wondered if it was really just superstition. Especially because you can propagate a lot of trees in a stool bed, so you wouldn’t think that mulch on the trunk would be harmful.
I decided to look it up just now and found this from PSU:
“Roots and trunk wood are quite different from each other. When trunk wood is buried in soils or mulches, it remains wet (or moist) which impacts or disrupts the exchange of gasses (oxygen and carbon dioxide) that are required to keep the phloem alive.”
So I guess what it comes down to is that gases can’t pass through a wet barrier (like how a breathable waterproof membrane will keep water out, but will only breath where there isn’t currently water on the other side), so if the trunk wood is constantly wet it suffocates. I always assumed the reason trees buried too deep died was that compacted soil against the trunk blocked air, but I guess it’s the water, not the soil. Seems like the rot is just a symptom of an already suffocated area.
I suppose it’s also why a lot of plants respond to that kind of condition by growing aerial roots—its a way of breathing in an excessively humid environment. In 2023 it rained here basically nonstop in July and August, and there was one day we had over 200mm (more than our average total for both months in 24 hours). I had a lot of plants grow aerial roots after that. They were 6 feet off the ground on the grapes.
So, in that regard it probably does matter for some plants that can’t easily grow roots from the trunk if the mulch is sufficiently dense and consistently wet. But even then, only when they aren’t dormant.
One of the disadvantages that I have found is using the wire around the tree to keep the mulch off the trunk is you can get shoots on some trees . I just pull the mulch back a little bit lift the wire trim them and put it back down if it happens .
Here in southern middle Tennessee…
When I plant a new tree… i add lots of compost and then a nice wide wood chip mulch ring.
For some trees that I want to encourage more growth… i will do that again the 2nd spring… more compost and woodchips.
For something like apples and pears… i may only do the compost and chips at planting… and only wood chips after that. These need to grow slower to discourage fire blight.
I normally have to do a little weeding each spring… and then add more wood chips.
This winter I collected several bags of maple leaves and put them down over the mulch back in December. That helps to suppress any weeds… i will put down more wood chips this spring.
PS… i have a guy that mows my yard… he does a great job and the price is reasonable.
Last year I let him start mowing my orchard too… every 2 weeks.
It looks much better when mowed every 2 weeks and I can check on my trees easily… no wading thru tall grass.
With those wide mulch rings and fruit tree cages in the center… not one single problem with him mowing around 33 fruit trees.
TNHunter
