Living or Dead Mulch?

Which is your preference?

I used to use mostly dead mulch, but have recently switched to using mostly living mulch. The living mulch eventually turns into dead mulch, so it has the benefits of dead mulch and helps build the soil, and then more living mulch comes up to replace it.

I really like using a wild mulch (no planting required) and love how living mulches provide an extra "canopy" for the soil and also provide great pollinator and beneficial insect habitat.

The living mulches may been a little more effort in the beginning for annuals, cutting them back some to allow the young crops to get established. But after that there's generally no or very little weeding required. For a food forest, where the plants are bigger, it has required almost no work at all.

Which one and what kind do you like to use and why?

Have you switched from one to the other or use different ones for different things?

When I 1st started my food forest I did a living much of daikon radish to "plow up" my compacted soil and dutch clover to fix 250lbs of nitrogen/acre. I also planted a few annuals/tomatoes between my tiny fruit trees. The tomatoes even self-seeded for a couple years with the other two.

Then after my fruit trees got bigger, I switch over to woodchip, then I started growing mushroom and I got firewood pellets. Since then my food forest is going back to living mulch.

Your post S Bengi got me thinking back on two different areas of my food forest. In both sections I did some earthworks, and the soil was poor in both spots.

In one section I didn't do anything, and the soil got baked and hardened by the sun. In the other, I cut some wild plants that were growing in that spot and laid them down as mulch over the earthworks. The mulched soil started sending up new plants everywhere, while the unmulched area struggled in a lot of places for plants to get growing.

It's amazing the difference mulch can make!

Steve, which plants do you like best for your living mulches?

I haven't had a lot of success yet with living mulches, but I'd really like to figure it out. I've been a little worried about using perennials since they kinda take over. Nevertheless, i decided this year I'm going to let the clover spread on the beds it tends to grow in anyway and see how that goes.

The problem for me with using annuals is that my growing season is short enough that the mulch doesn't get established any quicker than the crop, and then they both suffer in the summer heat.

One annual that has worked really well for me is Valerianella locusta/lamb's lettuce/mache. It reseeds itself everywhere, even in places I don't expect it to. It comes up in the fall, goes dormant over winter, then takes off early in the spring, before pretty much anything else. It's low growing, so it doesn't shade anything too badly to begin with. It bolts and dies off over summer, leaving a dead mulch that doesn't compete with anything - and lots of seeds!

Definitely LIVING mulch in my climate (hot, dry, mediterranean…)

I share all the living mulch plants I use and my reasons and results here:
https://permies.com/t/157111/Living-Mulch-Mediterranean-Food-Forest

The two main types of living mulches I use are creeping thyme and white dutch clover. I like both in and near the garden because of all the beneficial insects the flowers bring in. Also they're good cover for beetles and ground spiders especially after the warm season annuals get frosted.

Also I'll let a number of veges go to seed that also serve as chop and drop, ground cover or get harvested. Radishes are good as I like to snack on their seed pods. I'll also let mizuna, swiss chard, lettuce, kale, dill, parsley, arugula, mustard, orach and others go to seed.

Jan White wrote:Steve, which plants do you like best for your living mulches

Heal-All Prunella vulgaris is one of my favorites for annuals or smaller plants. It only grows a few inches tall, has nice flowers, and is medicinal. I also like henbit, chickweed, deadnettle and other low growing, well behaved plants for annuals.

In my food forest I let pretty much anything grow unless it is harmful like poison ivy, or if it starts to overgrow the food plants.

I went to tractor supply and they had big bags of wildlife food plot mix on clearance.  Its clover, radishes, greens and other thigs deer eat.  I'm thinking of trying it out in my food  forest floor.  I think I got around 20 pounds for $10.00

I do both. In my raised beds I mass plant veggies, eatable flowers, and herbs.  With the exception of Bermuda grass that occasionally sneaks in there's no room for weeds.  You would think crowding them in there like that production would go down, but it just doesn't seem to be the case.  It's kinda wild, beautiful, and productive.
For my food forest want to be, I have wood chips year round. So there's always something covering the soil, to help keep moisture in, and weeds out.  Since it's still in the getting started stages, I have a row of fruit trees that we have had a long time.  Last year I added some perennials.  In the spring I plant a lot of melons and squash, because they grow and produce better in this spot then any other spot . By early summer you can't see the ground. I have to put steaks in the ground when I plant so I know where to water .
Which one is better?  I can't say both have amazing benefits.

Living mulch over dead mulch…. Lately I favor lettuce as living mulch.  I let it go to seed, so there’s plenty of seed.  It germinates EARLY!  No room for weeds, and it’s yummy. I’ve started giving some thought to colors, red purple lettuce mixed with speckled, green only, all colors mixed together.

In places where I want a taller mulch I like comfrey.

Columbine make a nice solid canopy over the soil and in between other plants.

I was surprised to find at my Bulgarian house that there is no humus in the garden at all, its just fine, dusty, dirt. I can see from my neighbours garden they mulch by planting very closely so the soil is shaded.

Winters are cold, not sure if it's too late to try sowing a live mulch of daikon and clover.

Steve Thorn wrote:Which is your preference?

I used to use mostly dead mulch, but have recently switched to using mostly living mulch. The living mulch eventually turns into dead mulch, so it has the benefits of dead mulch and helps build the soil, and then more living mulch comes up to replace it.

Is everyone who prefers living mulch letting it turn into dead mulch so that the mulch will benefit the soil?

I leave the living mulches in place😊, to feed the soil, if I didn’t eat them myself.

And speaking of that reminds me of another favorite:  catmint “nepeta”, different from catnip.  The catmint is woody, dies to the ground, then resprouts  in the spring.  It makes a perfect little  hemisphere as it expands from its center, then is covered by blue-purple flowers which bees and other beneficials love.

To me, it always seems like it is self mulching because the mulch it forms when it dies to the ground is so thick nothing ever sprouts through.

Previous winter I covered my garden area with lots of leaves and composts and they ended up harboring so many slugs that I had no spring crops left. This year I just let nature do its course and multiple winter and spring annuals show up and keep the ground green. I have the following species: henbit, dead nettle, Persian speedwell, field madder, yellow rocketcress, chickweed etc. Some are already blooming quietly as early as January. They have shallow roots so I decided to just let them be and plant transplants directly in spring. By June they will be mostly gone and be no competition to my major summer crops. I want to see if the slug problem is solved by keeping no dead mulch.

The best annual garden I ever had was when I had white clover covering the whole thing. When I was getting ready to plant. I would put down cardboard to kill just the clover around where I was going to plant. I’ve also done well with lots of wheat straw, which the chickens were on in early winter, chickens would come off in late winter and I’d plant in May. I haven’t had the opportunity to use wood chips yet. Just got some to cover my orchard (hopefully one day Food forest) which is currently in the grass that was there before we planted trees.

For annual crops, agronomic and agroecological research has shown that living mulch improves soil qualities (moisture, structure, fungi, nitrogen, etc.) but interferes with crop growth via competition for nutrients and water. As far as I know, there haven't been any long-term studies, but I suspect the improvement in soil health may outweigh the competition over a period of more than a few years. Mowing/cutting back the living mulch around the time you plant your crops reduces competition.

I've linked some studies mostly focusing on living mulches for nightshades. For some of these, if there's a paywall you can get around it by replacing "doi.org" in the url with "sci-hub.ru".

Adamczewska-Sowińska, K., Wojciechowski, W., Krygier, M., & Sowiński, J. (2022). Effect of soil regenerative practice on selected soil physical properties and eggplant (Solanum melongena L.) yield. Agronomy, 12(1686). https://doi.org/10.3390/agronomy12071686.

Basinger, N.T. & Hill, N.S. (2021). Establishing white clover (Trifolium repens) as a living mulch: weed control and herbicide tolerance. Weed Technology, 35, 845-855. https://doi.org/10.1017/wet.2021.45.

Borowy, A. (2012). Growth and yield of stake tomato under no-tillage cultivation using hairy vetch as a living mulch. Acta Sci. Pol., Horarium Cultus, 11(2), 229-252. https://www.cabdirect.org/cabdirect/abstract/20123132645.

Boyd, N. S., Gordon, R., Asiedu, S. K., & Martin, R. C. (2001). The effects of living mulches on tuber yield of potato (Solanum tuberosum L.). Biol. Agric. Hortic., 18(3), 203-220. https://doi.org/10.1080/01448765.2001.9754884.

Hartwig, N. L. & Ammons, H. U. (2002). Cover crops and living mulches. Weed Science, 50(6), 688-699. https://www.jstor.org/stable/4046641.

Leary, J.K., De Frank, J., & Sipes, B. (2006). Tropical eggplant (Solanum melongena L.) production with a buffelgrass (Pennisetum ciliare L.) living mulch system in Hawaii. Biol. Agric. Hortic., 24(2), 105–116. https://doi.org/10.1080/01448765.2006.9755013.

Thanks for posting those studies, I am interested to see how they were conducted. I am in an arid climate where the benefits of the living mulch make the difference between growing a crop, and not growing one.

In my region we do not see crops suffering competition from the living mulches, we see multiple harvests/multiple crops per year, the last “crop” before winter being a period of grazing livestock, which brings nutrients to the soil from their manure as well as grinding and inoculating crop residue, as well as breaking through hard pan, and saving the fossil fuels utilized to remove and dispose of cornstalks or other residue.

One of my favorite living mulch is alyssum.  It spreads is pretty, smells good. It's a delicate plant so instead of crowding my veggies it just goes around them.  It doesn't get very tall, so doesn't steel the sun. It seems to do well in sun or shade. In my zone 9 b It's a perinatal.  also supposed to be great at attracting beneficial insects. It eatable, which is a must for my veggie garden. My family knows if it's in the veggie garden it's eatable.

Nigella, love in a mist is another great “weed substitute”.  Grows easily, tolerates rich or poor soil.  Germinates and reseeds prolifically, has a decorative seed pod, good for dried arrangements, and a minimal root system.

 It keeps weeds from germinating, shades out invasives, and when it’s in the way, easy to pull and use as mulch… chop and drop without the chop.

One thing it doesn’t do is make a good substitute for Nigella grown for  “black seed”, which has medicinal and culinary uses.  When you have a garden again, I will try the blackseed nigella, but if somebody gets there first, just let us all know!

You guys may enjoy this new clip from our Garden Master Course looking at the benefits of a living mulch and active root system in the soil year-round.

Thekla McDaniels wrote:Nigella,
When you have a garden again, I will try the blackseed nigella, but if somebody gets there first, just let us all know!

Sheesh!

That was supposed to say: when I have a garden again….,

My preference has always been living mulch.  I just saw the new garden master course excerpt talk.  Helen talks about adding organic plant residue to the soils, and she adds mowed lving mulch.  So best of both worlds?  Soil Health with Organic Plant Residues