My vegetable garden is adjacent to a very large pecan tree and pecan tree leaves, limbs and nuts fall into the garden all the time and have never caused a problem. I do use the chopped and shredded leaves as mulch and they don't harm the soil or garden plants.

Underneath the dripline of this large tree, I have smaller trees, vines, shrubs, perennials and annuals and all of them grow just fine. In the soil underneath the outer portion of the tree's drip line, I have grown veggies in an 'overflow' bed for years with no problem, even though there are pecan tree roots in that drip line area mixed in with the veggies. So, based on my decade of experience with having a pecan tree directly adjacent to the garden, I'd say no portion of the pecan tree is an issue for anything that I've grown near it....and I've grown everything near it.

One year I grew sweet potatoes as a 'ground cover' underneath the pecan tree and they did quite well in the dappled shade beneath the tree....and at the end of the growing season I dug up a lovely crop of potatoes. Another year I planted extra onions there in the dappled shade and they grew just fine too.

The only thing that hasn't grown well under that pecan tree is hostas, but the tree wasn't the problem....it was the deer who apparently think hostas are "deer chow".

Dawn

You're welcome.

Even black walnut leaves can be composted and used because the composting process breaks down the juglone into harmless components.

I wouldn't put a veggie garden adjacent to a black walnut because of the juglone in the roots, but having a peacan tree nearby and using pecan tree products like leaves, twigs, pecan shells, etc. just isn't an issue. Clearly, based on what I've seen with my garden, even the pecan tree roots don't have enough juglone to harm the garden.

On the list of things I'd worry about in terms of gardening, the minute amount of juglone in pecan trees wouldn't even make the list.

Dawn

George

If you are observing stunted growth or late blooms, my best guess is that phenol, which is a compound found in oak leaves, is present in a high enough quantity to slow down the plant growth. However, even though phenols are sometimes mentioned in literature, I don't know if anyone has done research that backs up the theory that oak leaf phenols stunt plant growth. I am pretty sure the phenols from oak leaves can inhibit germination though, so it is not far-fetched to believe they also could inhiit blooming.

I shred my leaves and add them in the fall, and then by spring they are mostly broken down. In the spring, I normally use grass clippings, straw or hay because they feed the garden small amounts of nitrogen throughout the growing season as they decompose. So for me it is oak and other leaves only in fall and everything else in spring. I think I read somewhere that it can take 8-10 months for phenols to break down enough that they don't inhbit seed germination. However, in my garden where my main form of soil amendment is my own compost, grass clippings and shredded/chopped oak leaves, I've never seen any sort of inhibition that I felt could be attibuted to the leaves.

Another thing to consider is the pH of your soil and your leaves. I have alkaline soil, so the slightly acidic leaves only helps my soil and doesn't hurt. I suppose there might be issues with adding leaves to acidic soil, but I have no experience with that.

I'm going to Google and see if I can find a phenol reference to link below. I'm thinking phenol is the cause of the problems you've seen.

Dawn

George

George, I have a lot of oak leaves and I never thought about them causing any problems with the garden. It's always something, isn't it? I can't say that I noticed any problems with them, but then we had such a strange year what with the weather and all it would be hard for me to tell.

I know you were only referring to blooming, but I've only seen phenols mentioned in terms of stunting. I was just wondering if the phenols that cause stunting and that inhibit germination might also inhibit blooming, although the puzzle there is that if the beans germinated fine to begin with, then how could the phenol inhibit blooming later, unless perhaps you added more leaves as mulch after the plants were up and blooming....or maybe phenol in the leaves leached into the soil every time it rained.

My first thought was too much nitrogen and my second thought was daylength sensitivity. Beyond that, I don't have any good guesses.

Ilene, I let mine leaves lay on the soil surface all winter after I have shredded and chopped them in the fall and piled them on top of the beds. It keeps winter weeds from sprouting in those beds. Then in the late winter or early spring, I either dig them in deeply or rototill them in a couple of weeks before planting. By then, they have at least partially decomposed into pretty small pieces. If some whole leaves blow or fall into the garden and aren't shredded/chopped and they get tilled into the soil, it can take those whole ones a couple of years to break down.

I've tried just leaving them on the soil surface and planting through them, but the leaves are just too, too attractive to pillbugs and sowbugs if I leave them on the soil surface of the veggie beds and I wouldn't mind that, except once seeds sprout, the pill bugs and sow bugs start eating the little seedlings....and they aren't shy about it...they'll climb those seedlings and nibble on them right in front of me. (This is what led to the use of Slug Go Plus to control the sow bugs and pill bugs.)

Dawn

I don't know how long it would take leaves to decompose if they aren't shredded first, but some of them, I'm guessing it would take a long time. Pecan leaves are great, though, because they get brittle and shatter when you step on them. So I guess you could say they shred themselves.

I like pecan leaves too because they are brittle and crunchy pretty quickly, unlike those tough old oak leaves that hold their shape simply forever.

In the past I have been able to hold leaves in place by placing either chicken wire or bird netting over the top. That works pretty well for me, but we are in a low-lying hollow with higher ground pretty much on all 4 sides of us, so we have some wind protection. I use landscape staples (those U-shaped wire things you use to hold landscape fabric in place) to hold down the bird netting since it is so lightweight.

My red oaks are finally turning red and I think their redness will peak in a day or two. We still have some post oaks with green leaves though, and the chinaberry tree has mostly green with a little yellow. Our tree's have behaved oddly all autumn and some of them have changed foliage color/dropped their leaves out-of-sequence compared to most leaves. Of course, it doesn't matter...they all lose their leaves eventually.

In other odd occurrences, the roses are blooming despite the cold nights and those little wild onions that blanket the fields in spring are blooming now along with the henbit.

Dawn