Leaves at Bottom of Plant Pot (to Create Leaf Mold)

Hi,

I potted up an Atherton raspberry yesterday, and used a mix of 1/3 sand, 1/3 coconut coir and 1/3 compost. To have an experiment, I placed an two inches of dry leaves at the bottom of the pot (actually a planter bag).

My idea is this: I don't really like having to buy coconut coir, as it is an imported product. I've also heard that it can be replaced in this kind of potting mix recipe by leaf mold. So, my idea is for the leaves to slowly turn to leaf mold, and so when it comes to the time to replenish the pot's soil, I'll have some ready made leaf mold, and won't have to add any/much coconut coir. And once again, I'll add some dry leaves to the bottom of the pot, and the cycle continues.

Any thoughts?

I might have concern that the leaves mat up and block water from draining. Does a potting bag allow drainage from the side? I have never used them.

The concern is easy enough to test. I could be wrong.

I think if you can crunch them up and mix with just a bit of the compost it could work? ...laid in flat not so likely as I think they would not get enough oxygen and would possibly turn anaerobic or interfere with drainage as Wayne mentions...we're talking about fallen dead leaves not green?

Leaves, even in a large pile outdoors seem to take forever to decompose.

I wonder if they were crunched up fairly well if they could mixed all through your potting mix.

I don't know if I'd consider the results "leaf mold" exactly since the conditions at the bottom of a planter are somewhat distinct from the decay situation that creates leaf mold from old leaves, but as a way of building soil and incorporating organic material, I am a fan.  In fact, I go one step further and use fresh vegetation (tree leaves or chop-n-drop field weeds of size, like giant ragweed) in the bottom of most pots.

I am a particular fan when I'm desperation-planting something that I don't have a place for, by which I mean, I don't have a container ready that's already got good soil in it.  Starting with an empty container and nothing good to put in it, I know out of the gate that the thing I'm planting won't have ideal conditions.  That's especially true if I'm scooping up field dirt (mineral soil, mostly -- I can always at least find it freshly dug and fluffy if I highgrade with a shovel around recent gopher mounds) to fill the pot.  I know damned well that the pot is going to be a heavy lump of near-concrete when I dump it after the season.  But if I half-fill the pot with vegetation and top with field dirt, the pot weighs half as much and doesn't do any worse.  Whether it does any better seems to depend on what I planted and how aggressive the roots are, but at least when I dump the pot into my soil bin (a container where I rework compacted soil from containers and stir in amendments) it's always got a thick layer of black goodness stuck to the bottom of the concretized chunk.  Which, after whacking it apart with my hoe, makes the resulting mix considerably better, and thus does my container soil improve, on average, over time.  

I'll be interested to see how this turns out too. Using local resources makes so much sense. When I've made leaf compost by bagging leaves up, I have observed that the bottom bags compost faster, not sure if this is because they have a bit of weight on top of them or because of protection from drying out.  Being in the bottom of a pot addresses both these things too.

I do what Dan describes and am happy with the results.

Maybe do a couple pots with just dry leaves, a couple pots with a mix of greens and browns, a couple with bigger chunks of wood in the bottom, whatever other variations you can think of. Then you can see what gets the best results for your purposes.

I grow a lot of annual edible plants in containers and since I am using soil that I purchased in order to increase the nutrient content and soil life, I usually place plant matter at the bottom of my pails then fill it up with soil.  This is an ongoing thing I do to always improve the quality of soil in containers.

The plant material does break down usually after a few months unless they are larger particles which I just wait.

During the winter months, I do soil shoots  in those 10 inch black containers, (mostly radish & buckwheat) and after cutting down my shoots, I place the rest of the plant material at the bottom of the next container I will use and fill with soil.  This breaks down very quickly.

Another thing I do is when composting in 5 gallon pails over the winter in a heated outbuilding, whatever is not completely composted, but lets say it is about 75% composted at the end of winter, I will add that to the bottom 2  inches of my containers mixed with some soil, then add soil to fill the container and then I plant in it.


I started doing this because I would have more pots for planting in.  If I did not do this, I would only have 12 pots to plant in, but doing this, with the same amount of soil & non composted or mostly composted organic matter at the bottom of each pot, I could now do about 17 pots.

This seems to be working just fine.

I did a garden bed like this before I knew about permaculture. I had a bag of potting soil and it wasn't nearly enough to plant in. So I made a pile of debris (leaves, pine needles, sticks, old pine cones, etc), threw some bbq ash in and dumped my potting mix on top. I planted tomatoes and basil in it. Not long after planting we had some minor flooding and the garden floated. I drove some sticks through it and into the ground to keep it from drifting away. It came back down on the same spot and I got tomatoes off of it that season. I was thinking of chinampas when I did it. We were next to a swamp and I knew about the periodic flooding.

Ryan Hobbs wrote:I did a garden bed like this before I knew about permaculture. I had a bag of potting soil and it wasn't nearly enough to plant in. So I made a pile of debris (leaves, pine needles, sticks, old pine cones, etc), threw some bbq ash in and dumped my potting mix on top. I planted tomatoes and basil in it. Not long after planting we had some minor flooding and the garden floated. I drove some sticks through it and into the ground to keep it from drifting away. It came back down on the same spot and I got tomatoes off of it that season. I was thinking of chinampas when I did it. We were next to a swamp and I knew about the periodic flooding.

Well I did a similar thing with my orchids and peace lilies. I got potting soil off of amazon and planted some flowers. It worked tho. Moreover, I tried tomatoes like you, they also grew great. Turns out even debris helps out alot.

This experiment has been performed many times, often by actual professors like Linda Chalker-Scott.  Although the idea is positive, we have to make sure that we are mixing the materials throughout. If there are two different materials used vertically and separated in the container, the moisture will tend to stay in the top material and not drain properly.  Using old leaves is fine, but mixing them into the soil is the key.

I also don't use fresh leaves because in biodegrading them, the material will extract things from the soil. I prefer to use ones that have already decayed because that process has already happened.
John S
PDX OR

Michelle Bisson wrote:I grow a lot of annual edible plants in containers and since I am using soil that I purchased in order to increase the nutrient content and soil life, I usually place plant matter at the bottom of my pails then fill it up with soil.

I started doing this because I would have more pots for planting in.  If I did not do this, I would only have 12 pots to plant in, but doing this, with the same amount of soil & non composted or mostly composted organic matter at the bottom of each pot, I could now do about 17 pots.

My house is very close to an old coal fired power plant.  I am not sure of the level of soil contamination after 50+ years of coal and flyash exposure, so most of my garden is also in containers.

I have been using a layer of organics in the bottom of my pots for a couple of decades with very good results.  All my outdoor pots start with 10-25% of organic fill in the bottom.   (I don't use bottom organic layer in pots that will live in the house.)

I vary the ratio of wood to dried leaves and weeds depending on what I am planting, the size of the pot, and how long the plant will remain in the pot.  

Potted veggies and other annuals get more leaves, little wood.
Pots for cacti and succulents get more twigs and wood, few leaves.
Larger pots, 5 gal or better, or those with more permanent plants, get a heavier ratio of branch wood and twigs.

Leaves and weeds at the bottom of a pot disappear inside a season here.  The soil level will usually drop as the organics break down, just like in the compost pile.  This makes room for top dressing and mulch as the plants get older.

Pill bugs love the material at the bottom, and the cavity that sometimes forms, so they accumulate there.  I empty the pots into a wheelbarrow (or a kiddie pool) on top of fresh compost at the end of the season or when I need new potting soil.  Then I let the chickens have their way with it.  The girls need to see only 1 bug and they dive in.  They clean out the bugs and other tasty bits while mixing the old potting soil together with fresh compost.  They bring any surviving twigs or branches to the top of the mix to be easily re-used in bottoms of pots.

Pots are refilled with a layer of leaves, weeds and wood, then topped with refreshed potting soil.  I add more pots and the cycle begins again.

This method works for me.  YMMV

I had a pot of ever-bearing strawberries and the soil had sunk to the point that the plants were too far down in the pot. I *really* didn't want to disturb the roots at that time of year, so I carefully tipped the whole pot out onto a shovel, filled the bottom of the pot with Wisteria leaves I'd just pruned, then set the shovel-full of plants right back on top. It worked just fine for a couple of years until I was called away on a family emergency during our summer drought and my son missed that pot. The plants might have been even happier if I'd mixed some dirt in with the leaves or some actual finished compost, but these were small berries and fairly undemanding plants. A heavy feeding plant may not have reacted the same way.