To Build Veggie Garden Soil, Just Add Leaves

I’ve been walking my daughter’s dog around Old Town Longmont where there are lots of big, old, splendid trees. The streets are thick with leaves. Trees grew like mad with all last spring’s moisture and though many leaves have already been raked, bagged, and picked up for municipal composting, we haven’t had much wind so there are still quite a few on trees, lawns, hellstrips, and all over the streets. In order to have a great vegetable garden next year without any back-breaking work, these are what you want to add to your beds now. If you don't have enough leaves of your own, just pick up some bags that others have put out on the curb.

This free, carbon- and nutrient-rich, soil-building addition, along with the earthworms and other critters that break it down, will do the hard work for you, making spring sowing and planting a breeze. I shred the bigger leaves, especially thick ones like cottonwood and oak, then fork them into my beds. Almost all leaf blowers have a reverse, vacuum setting that shreds leaves into a zippered bag for easy dumping. It’s not a heavy or expensive tool (but is kinda loud) and it will come in handy every fall, making short work of big leaf piles. Some people use lawnmowers instead but I find the leaf vac to be the right tool for the job. You can also use it to blow leaves out of gutters and off any beds with dryland plants that prefer gravelly mulches. These don’t like moisture-holding organic mulch, especially in winter.

Some of you probably have composting down already, so this may seem like Gardening 101, but it’s taken me several attempts to create a decent-sized, manageable pile that actually works and allows me to keep all my thinned, pruned, discarded plant material onsite. I add leaves to my veggie beds every fall but my compost piles never quite worked. They were too small, dried out too much, and the brome grass invaded. I’ve had a compost tumbler for years too, which works well for food scraps mixed with dried leaves, but it has rusted out and I haven't been able to get parts.

So, now that I have time on my hands, I’ve been building a big new pile using pallets and old hay bales for the perimeter. I re-read Penn Parmenter’s instructive article, “Weeds for the Compost”, then gathered the material I have around now: lots of chunky stalks of sunflowers, hollyhocks, kale, weeds, etc., for the bottom layer, dried leaves, horse manure and some llama/apalca poop from my neighbor, a couple of old straw bales, household veggie food scraps, coffee grinds, dirt. Alternating brown carbon layers (dried leaves, dried flowers, thinner stalks, straw) with green nitrogen layers (manure, grass clippings, food scraps, still pliable leaves), and sprinkling whatever dirt I can find in a thinner layer on top, we’ve built the pile in layers, wetting each one down well. (My non-gardening spouse actually likes helping with this.) Penn suggests a bottom brown layer 8” thick, then 4” green, 1” dirt, followed by more layers of 4” brown, 4” green, 1” dirt. As with most gardening tasks, I find there’s rarely one exactly right way to go about things so tailor recommendations to your own situation. Creating layers and wetting each one down is the important concept here.

My pile is only 2’ deep so far because it’s big – 8’X12’ - and I am pacing myself. It’s in full sun so eventually we’ll add some hay flakes on top or fashion a cover, maybe a tarp mounted so it can easily be opened and closed, and won’t blow away. Meanwhile, I’m also forking more leaves into the existing beds, and adding some soil minerals, (Azomite is the favorite of vegetable gardener extraordinaire, Garden Father Larry Stebbins), wetting them down well, and covering the top with flakes of funky, old hay. I have it around, plus there seem to be fewer problems with herbicides on hay than straw these days; know and trust your sources! I don’t worry about hayseeds because if you leave the flakes thick & intact very few will sprout and those can easily be pulled out. (If you can get it, second cutting hay has no seeds.) Rain and snow will still penetrate around the edges of each flake over the winter and early spring.

In our drier steppe climate, I find covering beds in winter helps tremendously with soil building and makes for a lot less work in the spring. If you can’t get hay or straw, the leaves that you fork in and wet down will still help a lot, and you can add more on top. Most of this fall compost-building and soil alchemy is pretty light work once you gather the materials, plus it’s incredibly satisfying and completely worth it come spring.

Enjoy this beautiful extended fall. The cold weather is coming!

Jane

Pictured is my Porcelain Vine (Ampelopsis brevipedunculata) with its beautiful, multi-colored berries before the hard freeze. It’s in the grape family and can be aggressive in wetter climates. Mine is 20 years old and very well-behaved.