If water penetrates then i would have to think that nutrients would too. Having said that i can't be 100% sure.

How do you find it for water? I am using some on my garden and find that the fabric has to get wet before it will allow water to be absorbed, in other words a mist just seems to lay ontop of it. I would like to mulch my trees but if fabric is acceptable then I think it may be easier.

I have half of my trees under black polypropylene weed barrier, and half without. The stuff without is about 4 years older than the stuff with the barrier, but these have now just about caught up in size and are actually producing - while the others w/o are just now beginning to bear fruit. Makes a big difference here with evening out soil moisture and temperature.

I wouldn't worry too much about fertilization, it will go right through. Watch out for gophers.

If the water passes the nutrients will as well. You probably won't need to apply fertilizer as there will be no other vegetation competing with the trees for water or nutrients.

Don't know how the voles would react to fabric. But critters under there would be a concern.

The Fruitnut

Gad! It's horrible stuff.
Weeds/grass will sprout in mulch on top of landscape fabric and will root through it. Some stuff, like bermuda grass, can and will come up from underneath and can penetrate it.
While it will allow some water and nutrients to pass through, when I've had occasion to remove it, the soil underneath is hard, dry, almost like concrete, as it prevents normal decomposition and deep cycling of nutrients/organic matter by earthworms and soil microorganisms.
Use it if wsnt, but I won't make that mistake again.

I have not been happy with landscape cloth as a weed barrier either. Eventually it traps soil on top of it and weeds actually begin to grow in it. Other weeds can grow right through it.

It does have valid uses in the landscape, though, primarily that of holding gravel or small rocks where you want them to be, and not gradually migrating into the soil. For example, if you are building a retaining wall, it is very useful in containing the layer of gravel behind the wall.

Gophers, not moles, are my bane here, so I don't have any advice on what mulch might suit your situation. I do see the problem. Maybe you could underplant rather than mulch.

Here is a link that might be useful: WSU suggestions for orchard floor management

... but if you are happy with what you have, and it is working for you, by all means stick with what you are doing now. Sometimes I try to fix a problem that doesn't really exist.

Rosefolly

Landscape fabric per se is kind of hard to work with -- not sturdy enough to keep a lot of the deep-rooted weeds from growing through.

I have been using old carpet and carpet padding, most of it recycled from the curbside on garbage day, under as many of my plantings as possible. I consider it a real blessing -- weeds won't grow through it (although yes, some annual weeds will grow on top in the mulch during moist weather, but these are easy to remove), and it keeps the soil much more moist underneath.

I just sprinkle/spread the fertilizer on top, it goes right through with the water.

Often on Garden Web, this pro-con discussion on weed barrier comes up. It's important to note, I think, that growing conditions are far from uniform around the country, and where this may be a great thing in some places, it isn't in others.

The Soil Conservancy here is alive and well, and every spring sells bare root seedling trees along with what they have found to be the best means of getting them to grow. This includes stuff to protect from deer / rodent damage, and weed barrier. I've planted several hundred trees here, and doing a lot of trees gets expensive pretty quickly. But I did give their recommendations a try, and pretty quickly noticed that these trees and shrubs grew at twice the rate of those where I couldn't afford the weed barrier. I think its more a question of retaining more even soil temperature and moisture, as well as eliminating a lot of competition for water from grasses and stuff. With that experience, I've been doing my new fruit trees with the same stuff, and covering the older ones as I can afford it. Again, they grow at least twice as fast.

I live where the annual average precipitation is 13", and most of that falls as snow. It rarely gets above 25% humidity. Dry soil, usually in the winter, kills more plants than anything else.

Your milage, as they say, may vary.

David, excellent point. I am curious about your control method, though. Do you find this works better compared to trees planted with alternate weed barriers (such as cardboard or newspaper layers plus mulch), or to trees planted without a weed barrier of any kind? If you find it the best of all, it might be worth using it for a couple of years to get plants off to a good start even if one were to remove it later and replace it with something else.

Rosefolly

Rosefolly, I have, actually, tried using cardboard/newspaper covered with grass clippings. This works pretty well in my flower beds, but my impression, out with the trees in the border, is that the paper may work as a wick, drawing moisture up from the soil, particularly in the winter. I know it sounds bizarre.

That doesn't stop me from using all the cardboard and newspaper I can find with the more established trees. But the idea is more as a soil builder, not a weed barrier.

I'm trying, this summer, on a couple of new ornamental trees, soaking newspaper and putting down a 6" thick layer all around, and covering that with grass clippings for looks. We'll see in the winter what happens - but to be honest, the main reason I did it is for the night crawlers - once they discover that paper, its gone, and I have some beautiful soil where it was.

Despite the similarly low rainfall your situation is almost the exact opposite from mine, which might perhaps explain why our experiences are so different. We get an average of 15" of rain and it all comes in the winter -- so our winter soil is very wet while our unirrigated summer soil (sandy clay) is bone dry. We would not have wicking in the winter with all that water present, and would be watering in the summer so again, no wicking.

I should clarify that on the trees that I am using the fabric, I have left a 1.5' diameter around the tree without fabric so voles can't hide underneath. The rest of the trees just have the crushed stone around, with nothing underneath. My local orchardist suggested the stone to deter voles. I haven't seen any voles (or signs of their presence). Maybe its working. On the Adam's County Nursery site, under the Planting Guide section, they suggest just using the crushed stone. The fabric was my idea. I think I'll take it up, that seems to be the overall opinion I am getting. I would simply use the stone all the way around a 5 foot diamter of the tree 3" thick but the stone gets expensive. I guess it would be worth it in the long run.

How many of you spray roundup around the base of the tree to control weeds?

Thanks for the link, rosefolly. I'll dedicate some time to read it.

If you're going to put mulch on top of the landscape fabric, why use the fabric to start with? I agree with Lucky. In my experience, weed fabric (under mulch) is nothing but a horrid nuisance. In certain applications, I have used weed fabric without mulch quite effectively, but if I'm using mulch, I don't even see the need for landscape fabric.

Carpet can work OK if you can overlook the trashiness, you aren't worried about possible chemical contamination, and you keep the weeds cleaned off. Without maintenance, it too can eventually become a real problem. From talking with people that have paid me to rid their landscape of these former weed barriers, it seems that the barriers work effectively for some time but become impossible messes quickly as soon as they are taken for granted.

I use mulch and roundup with pretty good results. Sometimes, I also use a pre-emergent. I can't think of any better system to prevent weed growth, and, as everyone knows, mulch has many benefits. Speaking of pre-emergent, does anyone have a favorite pre-emergent what works best for the money?

speaking of mulch... when I applied hardwood ground mulch to my trees at planting last November, my local nurseryman gasped. He insisted I remove it not just because it attracts and harbors voles but hardwood mulch robs the soil of nitrogen as it decomposes. Leading me to the question: what are you using for mulch, then??

I should comment that I mulch with wood chips and/or shredded oak leaves over the top of the old carpet. I don't want to see old carpet in the garden. I'm not concerned about any possible chemical issues with it.

Yes, putting mulch on TOP of weed barrier of any sort does let weeds grow into the mulch, but I've always found these to be much easier to control, since the root system doesn't penetrate the barrier with enough vigor to make the weed hard to remove. As you said, herbicices and pre-emergents also help a lot.

The most cost effective way to buy pre-emergent herbicide that I've found is to go to a farm supply and get whatever brand of Trifluralin granules (same as A.I. and concentration as Preen)they sell in a large bag, usually 50 lbs. Cost is about 1/3rd to 1/2 of the cost of buying Preen brand or similar at a Home Depot type store.

Dennis
SE Michigan

thomis,
That's an old gardening myth that's been debunked, but unfortunately continues to be propagated, even by folks in the gardening/landscape industry who claim to know what they're doing.

Surface-applied hardwood mulch or wood chips - even fresh 'green' woodchips do not - I repeat - DO NOT 'rob the soil of nitrogen'.
Now, if you mixed a bunch of wood chips into the backfill in your planting hole, or tilled a load of wood chips into your garden soil, then, yes, your plants will likely encounter some difficulty in trying to out-competing the soil microbes for available N as they carry out the normal breakdown of that woody material.
N availability is the limiting factor in how rapidly woody plant materials break down(that's why we use wood chips, shredded wood, pinebark, etc. as a mulch!), but, applied to the surface, no appreciable competition will be occurring. Wood chips have no mechanism for magically reaching down into the soil/rootzone and sucking up organic or inorganic nitrogen. I'll concede that there *might* be some minimal competition between decomposing fungi, bacteria, etc., and fine feeder roots right at the soil/mulch interface, but this won't be sufficient to cause chlorosis or failure to thrive.
And, contrary to the 'robbing' myth, as the microbes break down woody material and earthworms, beetles, etc., cycle the degraded organic material downward into the soil, a significant amount of the N contained in the woody material, as well as N captured from the atmosphere in the decomposition process will be made available to the plant.