leave it

I came across a study that poinked my interest immediately. Who studies this?

A chemical analysis of 100 municipal leaf samples collected from across New Jersey shows that leaves are a valuable source of all crop nutrients. Although nutrient concentration values vary considerably, the application of 20 ton/acre of leaves would add on average 400 pounds of nitrogen, 40 pounds of phosphorus, and 152 pounds of potassium.

So I thought it would be fun to ballpark what that translated to in my 750 sq. ft. of planted space (which excludes paths).

An acre is 43560 sq. ft. Divide that by my 750 sq. ft. and you get 58.2. So the actual planted area of my garden is about 1/58th of an acre (yikes, so tiny!)

The amount of leaves I’d need to put onto my garden to replicate the 20 tons/acre cited in the example would be about 700 lbs.

I don’t weigh the leaves I collect. Absolute negligence.

But 700 lbs. doesn’t seem out of the realm of possibility at all. Those tarp-loads are heavy, and I couldn’t even begin to guess how many loads I collected, let alone their weight.

I believe it was many more than 700 pounds, but let’s use 700 for convenience. That would translate to almost 7 lbs. of nitrogen, 2/3 lb. of phosphorus and 2 1/2 lbs. of potassium. Nice.

But (isn’t there always a but?) all that goodness isn’t like plopping down a bucketload of nitrogen or potassium:

The abundant carbon content of leaves leads to extensive development of fungi and bacteria in the soil which uses up the supply of available nitrogen for the production of microbial cell tissue. As decay proceeds, the carbon-nitrogen ratio decreases and some of the nitrogen becomes available to plants. Because of the high carbon content of raw leaves relative to their nitrogen content, there will likely be very little of the organic nitrogen in leaves available to crops for a period of time after application. Observations of crops (including legumes) planted on soil to which leaves have been applied indicate that plants suffer from a temporary N deficiency unless additional N fertilizer is added.

In human talk, you can’t just dump leaves and get a poof of nitrogen immediately useful for your plants.  It takes time.

What does this mean to me? Uhhhh…

Quantifying gardening is like stapling jello.  Mostly stupid, but fun.  I think it means that leaves on the garden are good.

Let’s go with that.


mulching opinions

Mulch is a given for most experienced vegetable gardeners. It cools the soil, retains moisture, smothers weeds, and when it breaks down, adds organic matter to the soil.  I’ve tried a few different types in my day, and wanted to spout some old guy opinions.

Hay: Love the smell and the ability to cover a large area with an armload.  With hay straight from the bale, normally the individual pieces are so long that after time, the more persistent weeds will find their way into the light.  If I use hay, I’ve learned to run over it a few times with a mower.  A shredder would do the same or better.  Of course that makes the pieces smaller and gives better coverage, but also dramatically increases the amount of hay I need. It’s not free in my case. That being said, shredded hay, when it’s free, makes a beautiful mulch.

Straw: Not at all my favorite mulch when used as-is from the bale. The stems are hollow and woody with less nutrient value than hay. Weeds poke through even the heavier applications of straw eventually (in my experience).  It’s tough to nestle small seedlings into whole straw.  But as with hay, shredded straw is a different matter, and it actually makes a pretty good vegetable garden mulch. Again, I don’t have free straw.  I realize that many really good gardeners mulch with hay and straw. They’re just not for me unless I can find some freebies and do the shredding.

Wood chips: Some gardeners swear by wood chip mulch. Also not for me except in paths. The stuff I get free from the county isn’t screened and there are just too many large pieces for anything other than paths (which I do cover with wood chips when I can). Even bagged chips seem iffy to me, because since my crops are rotated, there could be small seeds to plant in any given bed any given year. If the large chips have worked into the soil, that could pose a problem with germination of tiny seeds.  Shredded bark is probably an excellent mulch, but way to expensive for my tastes.

Leaves: Whole leaves aren’t a great mulch. They eventually sog down and mat together, not a good environment for most vegetables. But shredded leaves are a whole nuther matter. You’re probably noticing a pattern here. When in doubt, shred.  It makes all the difference.  More surface area, more air space, better water flow.  Free.

Grass clippings: Probably my favorite mulch. When applied correctly (maybe 4″ deep, depending on the plant size, dried for a bit in the sun) they’re awesome. Weeds won’t normally pop through a good mulch of grass clippings, and they return organic matter and nitrogen to the soil. My neighbor sometimes lets his field grass get pretty tall before mowing and lets me help myself to the clippings. They’re easy to pick up, but face the same drawback as hay; too much length to effectively keep weeds from popping through. Shred. The only problem that I’ve ever had with grass clippings applied correctly is getting enough of them. I’ll shamelessly stop the car at a neighbor’s curb and scarf up their brown Ace bags, but that can be a mixed lot. Sometimes even nauseating.

My opinions only.  Not scientific, not thorough.  A permaculture system would negate most everything I just said. But no matter what the material, your garden needs mulch.

but first…

You’d think after 38 years worth of organic vegetable gardening, I’d be able to hang up my ‘Dr. Garden’ plaque and smile at the junior peach fuzz apprentice gardeners.

Almost the opposite.

When I semi-retired two years ago I realized that I had been doing a great job of recycling; recycling a lot of my own wrong-headed ideas and practices.

And then I decided that I would start learning. From others, from my own mistakes and successes, from nature.

The first thing that I learned, the thing that a wiser person would have caught on to decades earlier, was that soil comes first. You feed the soil, not the plant. Sounds so basic, but it was enlightenment.

The second thing, a thing I sensed but hadn’t quantified, was that nature won’t tolerate a void. Soil left bare will fill itself with weeds or grass. If you don’t plant it or mulch it, nature has its own party in the breach.

The challenge is to set one’s own party agenda.