You sound like you have some good perspectives, and your previous success indicates that you pretty much know what you're doing. It would help a bit to know where you are, such that people in the same general area could weigh in about weather.

The "no weeds" and stunted plants observations are somewhat suspicious, and I have to wonder how much you know about what might have happened to your leaf mold before it got to you. Perhaps some contamination? Or maybe it's your own? Though I guess if your container tomatoes are doing well, with the same soil and leaf mold, that might be less of a concern. If the bed is in a different place than the containers, one might wonder about the possibility of herbicide overspray from a neighbor. Containers do warm up a lot faster, so if your soil temps were especially low in the spring, that could have stressed the seedlings in the bed.

Thank-you daninthedirt for offering possible explanations for me to think about. My neighbor calls his leaf mold 'compost' but in reality it is no more than leaves from his poplar trees & trees(Maples, Locust & Oak) in the city park that our homes are next to.

When I typically use it in spring, it is well-broken down for the most part-resembling soil-this is what I added to my containers. In the fall I added a couple of inches of the less-broken-down leaf mold to the raised beds & wondered if that could've contributed to the poor soil.

No chance of herbicide overspray since my closest neighbor(guy who makes leaf mold) doesn't spray and my property abuts city property which is mowed only-no spraying. My husband has been suspicious of the neighbor's leaf mold since this happened but he knows little about gardening and he's the one who built & filled the raised beds originally so he probably feels protective of them, lol! Anyway, I'm always pointing out to him how leaf mold has worked wonderfully as mulch in my perennial beds. May have to eat my words.

I live in Niagara Falls, Ontario, Canada and all my neighbors have vegetable gardens which I get to view several times a day when I walk my dogs. :) All their tomatoes, zucchini, beans, peppers and what-have-you are huge, healthy & abundant. I have serious veggie-envy! My neighbor offers his leaf mold to everyone but I'm the only one to use it apparently. Now, I feel like my garden is shaming me and will rip it out shortly, lol! This is the first time I've ever encountered this problem!

I'm not inclined to believe the plants I bought were somehow to blame for their shortcomings but believe the soil is the problem, darn it!

Just some speculations but depending on the pH of your native soil adding all the leaf mold can temporarily acidify your soil pH, perhaps down into a detrimental range. The less decomposed it is the greater the acidifying effect.

Then there is the allelopathic effects of some leaves, especially locust and to a lesser degree maple.

Then the nutrient issue arises. Are you counting on just the leaf mold to provide nutrients for the plants? Possible IF there is an active soil food web in the bed but far from probable. And the lack of even weeds would tend to support that.

Dave

Hi digdirt2! I did suspect the leaf mold was poisoning the soil and had concerns that it was like juglone from Black Walnut trees that was inhibiting growth. Don't believe we have any black walnut around here but if locust & to a lesser extent, maple, can be detrimental, than my soil is ruined. My neighbor does get leaves(volunteered) from other neighbors to add to his 'compost' so the possibility of even greater toxicity exists, unfortunately.

When the beds were originally filled, we had added much manure and some compost to the triple mix base hoping to enrich it but I had plans to plant a winter cover crop of buckwheat or clover-which I didn't get around to. Instead I shovelled alot of leaf mold into it before final hard frost. :(

What can I do now to prepare the soil for fall planted garlic? Do I need to empty the beds & start fresh or add something to it to sweeten(so to speak)? Please advise, since if I get started on ripping out plants this week, I can amend it(if possible) by the week-end & hopefully let it sit until October when I'm ready to plant garlic. I'm hoping I can fix this-guess I'll need a soil test kit!

Additionally, is this stuff inevitably bad to use as mulch too? My plants seem to be doing alright with it around them.

First I gotta say leaf mold in and of itself is good stuff. It only becomes a potential issue when it isn't fully decomposed, tilled in, and used in very large amounts. Lots of discussions over on the Soil forum here from folks who made the mistake of tilling in large amounts of only partially decomposed leaf mold and payed the price.

As a mulch, in the normal use of the word, no problem. As a soil amendment, assuming it is fully decomposed, no problem Even mild allelopathic issues can be reduced by good composting. We all know of the issues associated with black walnut but often forget the other trees in the same family have similar, tho lesser, issues.

Then there is the pH effect. Without knowing your soil pH using lots of it without compensating with lime may create problems. Again, if fully decomposed the pH of it returns to approx. 7 but if your soil was quite acidic to begin with then lots of it may be a problem.

So what to do? First I'd determine the pH of the beds and adjust if needed with lime. Then I'd attempt to compensate for the lack of nutrients AND the partial decomposed state by mixing in something high in N - your choice. Personally I'd use some plain old 10-0-10 if I wanted to be planting in it soon. But if you can let it sit over the winter then you could also use urea, blood meal, even fresh manure. But no planting in it with those for at least 90 days. If fall garlic is all you have to plant then treat one area for it so it can be planted and let the rest sit over the winter.

For future reference I'd limit the role of the leaf mold to mulching or get a pile from him now that I wanted to use next spring, stockpile it somewhere, mix some of the high N stuff in with it and let it continue to decompose over the winter. In the mean time look for a local source of good quality, multi-component, compost to use instead.

Hope this helps.

Dave

Let me add that leaf mold is my primary mulch. I love the stuff, and dig it in regularly. My alkaline soil needs the acidification. I've also got lots of leaves. But as Dave says, the nutrient value is limited. To the extent it is not well decomposed, of course, it will consume soil nitrogen. But as long as your leaf mold was just treated as an amendment, rather than as a main component of the bed, that shouldn't be an issue. As to alleopathy, I believe that at least juglone breaks down in a month or so in the soil, so while I might shy away from adding more of your leaf mold to your soil, I wouldn't be inclined to rip out your garden.

I think that seeds are usually reluctant to germinate in a medium with allelotoxins, so it might behoove you to do a test with seeds on that leaf mold, and that test would probably just take a few weeks.

So, Dan. I'm getting the idea that allelopathic is what happens with black walnut trees? Should I not be adding my black locust leaves to my compost? Nancy

Agree with Dave that it sounds like you need some nitrogen because of the uncomposted leaves you added to the soil. I'm in a similar situation. I have expanded my vegetable garden these past couple years and my homemade compost has been spread thinner (currently expanding my compost operations). I've always done sheet composting but now I'm relying on it more. However, since my lawn has decreased in size I now have less grass clippings to add with the shredded leaves in fall. As a result my carbon/nitrogen ratios have apparently become unbalanced and my garden is really paying for it this year. Slow growth and poor production from most things except root crops and
legumes. I'm gonna try using alfalfa pellets as a nitrogen source this
fall and again this spring.

Rodney

The problem with a walnut tree is when you plant stuff underneath one, and the fresh leaves fall on the bed. In fact, I think juglone can be transmitted though the roots as well. In principle, if you compost walnut leaves for a long enough time, I am led to believe that the juglone will decompose. I have no advice to give about how long that might take, though. It takes a healthy population of soil microbes and an aerobic environment to do the job.

Juglone does not have a lot of water solubility. So if it gets in your soil from the surface, it won't end up deep in anaerobic areas, and it won't spread out. That means that a bed polluted with juglone will probably recover once the source of juglone is removed.

You know, I've never had much luck with growing vegetables in any mix that didn't have actual soil (dirt) in it. There's always something missing.
Another thing is that peppers, and to a lesser extent tomatoes, can be permanently set back by cold, wet conditions at planting time, from which they never recover. Your container toms may have recovered because containers warm up better during the day and also drain better. Just throwing some thoughts out there.

In addition to Dan's points if you are hot composting a well balanced pile with a good carbon:nitrogen ratio then juglone from any of the allelopatic varieties - which as mentioned include Black Locust - will break down much faster. I have read reports of anywhere from 60-90 days but have no personal experience with Black Locust. I have some Black Walnut but primarily oaks, pine, cedar and hickory and I try to avoid incorporating much of the walnut. Why ask for trouble. :)

On the other hand a cold compost pile or one where the C:N ratio is out of whack could take much longer for the juglone levels to drop.

Rodney mentioned alfalfa pellets as another good source of N to add to a pile in addition to the other sources I mentioned above. Of course there are many other as well. If you happen to have access to an orchard rake up the ground fruit and add it, hair, feathers, cottonseed meal, all the kitchen scraps, and if you do any canning all the left-overs or any old out-dated jars of foods can do wonders for the compost pile.

Dave

Well, you've given me alot to think about & now plan for making the soil better. I suspected the container tomatoes were doing well because the leaf mold mix added to them this spring was the well-composted stuff after neighbor turned over the pile. The leaf mold added to the beds in the fall hadn't been properly mixed so there were composted leaves combined with uncomposted leaves.

At the time, I didn't have the strength or energy to dig deeper into the center of the huge pile last fall to get to the well-composted stuff. My bad :( Having never in the 20+years I've been gardening EVER experienced anything like this, I didn't imagine I'd ever have a problem!

I did suspect the cold/wet spring might be a factor in the slow growth and since I planted out weeks earlier than I typically do; I worried I'd set them back too much. That said, I have always had plants recover themselves eventually but these did not which made me think something else might be inhibiting their growth.

I do not compost at this house(been here 3 years) that is, I discard all food waste for the city to pick up weekly but don't do any for myself & I'm not inclined to at this point. I do know the value of it & had previously composted for 25+ years but I will have to buy compost.

I'll pick up a soil test kit & figure out the ph before I add lime or anything else and attempt to plant anything this fall.

Relieved that I can continue to use the leaf mold as mulch since there's tons of it at my disposal and all my garden beds can benefit from mulching :)

Sad that I'll be buying tomatoes & peppers for sauce this year!

Thanks for all your help. My husband seemed a little smug when I told him the leaf mold could be problematic. Sheesh!

Again, I would do the seed test (at least before the next crop) on your leaf mold. If seeds don't germinate in it for whatever reason, it's not good for your soil. I agree that nitrogen deficiency might be a problem, but unless you saw a lot of chlorosis as well as poor plant growth, it may not be a dominant factor. A reputable soil test would be of value in this regard.

For little more than the cost of a home test kit you can usually get a professional soil test done at your local county extension office. The home test kits are notoriously inaccurate as they are really testing the pH of your water. I agree that Dan's seed germination test could be very enlightening.

Dave

I like to mix amendments deeply into the soil ...mixing them with the original; top soil. Some don't believe in doing that, but I believe it speeds up processes.

I would guess that your ph is somewhat low. If you have received the amount of rainfall I have this May, June, and July, it would show up any weak spots...unprecidented rain here except 2003. I too suspect like digdirt that your nitrogen is low. I have black walnut trees, but their leaves do not end up in my leaves because the walnut leaves fall a month ahead of the other leaves and are asll dried up and gone by leaf time.

Insects aren't the fault of poor soil, and the white leaves on the zucchini could be powdery mildew - again, not soil related. Are you using the same soil as last year? If so, you need to add fertilizer to replace the nutrients your plants used last year. Leaf mold can be a good organic amendment, but compost cannot take the place of fertilizer, whether it be an organic mix, composted manure, or even...Miracle Grow.

Daninthedirt, I'll try sowing some lettuce seeds tonight but it feels like a futile exercise since the beds don't even have weeds growing. Oh, I do have a catnip plant in the corner of one bed that is doing really well...go figure ;)

wayne_5, I like to mix in amendments really well too. I just wish I hadn't been too hasty to add the leaf mold and then mix that in very well...:0

lgteacher, I was amending the soil between growing seasons with leaf mold. I also fertilized all veggies regularly until it became apparent it was all for nought. I didn't suggest insect damage was from my poor soil. It was just an observation that insects were getting at the leaves & fruit before I did.

I'm not a newbie gardener and am aware of needing to feed the soil. I was just thrown a curveball when my plants were performing so poorly & in all likelihood, the leaf mold I added seemed to be detrimental to my veggie plants. A lesson I learned is not to get too complacent about anything, lol!

If low pH turns out to be your issue, the quickest fix is wood ashes. That would get it ready in time for spring planting. I second the recommendation for a professional soil test (and if you only get pH and nutrients tested, the cost is comparable to that for a home test kit).

Sow seeds in the leaf mold. Not in your bed. The issue is the leaf mold. Your lack of weeds is already probably telling you that there is something wrong with your bed (which may or may not be leaf mold). Do you have some bigger seeds than lettuce? Pea? Bean? Lettuce seedlings are pretty small and hard to identify.

As to pH, I can't imagine a bed so acidic that weeds wouldn't grow. I also can't imagine a bed so toxicly acidic from leaf mold. But sure, get a good test done.

Yup, I've got some bigger seeds(peas, beans)that I could sow in the less-than-composted leaf mold. Will have to put some mesh over it tho-since squirrels keep trying to dig up everything I plant!

Have contacted a professional for a soil analysis-just waiting for an email back with a price-says turn around is 5 days only and is close to where I work so it seems pretty good. Just curious but how much soil am I typically expected to provide for a sample? Is there anything I need them to check for or is that all included in the analysis?

Hmmm wood ashes, slimiest_okra? How much would I need to add? Beds are 4x4 and there's 3 of 'em.

Depends on what the pH turns out to be. Let us know.

Do it in a small bowl covered with plastic wrap. Maybe indoors? If critters are going to pull up your seedlings (and yes, squirrels love to do that) it's not going to be much of a test.

My extension service wants about a pint of soil for routine analysis. Yours may differ.

Be careful about wood ashes! My soil is alkaline (even with added leaf mold), and to me, wood ashes are simply toxic. But if your soil is acidic, go for it.

Oh hey now that's easy daninthedirt! If indoors I just have to keep cats out of it!

Just told my boss(I work in horticulture :0) who was surprised at my rookie mistake, lol!

Well, cats will probably add to what's in the bowl rather than pluck stuff out of it. Not that you wanted to know that ...

Update: soil test lab didn't call me back-on holidays. Will send sample off to university for testing instead.

In the meantime, 4 days ago, I planted 5 pea seeds in a bowl of the leaf mold, as per daninthedirt's suggestion. It was a struggle to find some of the only partially broken down stuff since the majority of the pile is well composted now which is good news for fall mulching.

No germination of pea seeds yet. I have this in the kitchen windowsill and so far no curious cats have gone into it and removed or added anything, :)

I pulled all plants from the beds and dug up & removed some of the soil and sure enough, I found uncomposted leaf mold about at root level and below. So I dug it up & removed it all. This we/end I will add lime probably and mix it well, assuming I have test results by then.

The tomatoes I grew in containers are doing beautifully and will probably get a crop of about 50 large toms and consistently getting lots of cherry tomatoes so I don't feel all is lost. I will still have to buy tomatoes, peppers & zucchini for sauce-making but that's not a significant hardship :)

Thanks for all your advice-will keep posted!