mulching in the PNW?

Hello everyone. I'm new to permaculture. Right now I'm reading everything I can get my hands on, as well as following the design process laid out in Jacke's Edible Forest Gardens Vol. II.

I'm a total beginner gardener (my experience extends to one season with a couple of Square Foot Gardening beds of veggies). I had planned on growing vegetables this year and was using the methods espoused in Steve Solomon's book "Growing Vegetables West of the Cascades" (I live on Vancouver Island, near the San Juan Islands). In this book Solomon states quite emphatically that you cannot use mulch systems in our climate because our winters are not cold enough to kill off all the pests that make a home in them over the winter. He claims that using mulching techniques results in pest overloads in a short time.

I really bought into this message and was shunning all mulch methods. Then I started studying permaculture where it's all about the mulching! So can someone please put my mind to rest about this issue?

I'm on Vancouver Island too, and also a newbie to permaculture. I've had two years of vegetable garden in a tiny townhouse backyard, and this is my first year in my own home and suddenly I have way more room to work with. My own experience was my first year gardening (two summers ago) I used straw as a mulch, but only very lightly and not until summer was well underway. It was a pretty dry summer. I didn't have many slug problems. Last summer, I mulched way earlier and it was a wetter spring, and I had major problems with slugs. (No weed problems though!) With the mulch, I also could water less and I had fewer things die when I left for a week and it got ignored. I considered using Sluggo. The slugs got a lot of my crops before they had a chance to establish themselves, and nothing I tried was really that effective. Now that I'm in my own place, I'm thinking of using mulch, but also raising ducks. I may try copper around the outside of the beds, though it's pretty expensive. I'm also going to rethink the Sluggo. I don't think I would put it right in my vegetable beds, regardless of how safe the manufacturers say it is, but I might sprinkle it around the outside. I'm not sure how it's regarded by permaculturists though.

Thanks, Catch. We're in Duncan.

Have you left mulch in place over the winter? Was the pest problem worse the following spring?

I, too, am thinking of getting ducks. I love the sounds they make and hopefully we'll be putting a pond in as part of our design plan.

I mulch in perennial systems, but all my mulch is seasonal, and eventually turned under in my intensive annual garden.  I have been experimenting with galvanized barriers as well, and believe they have an effect, but have not run conclusive trials.  A living cover-crop and catch crop, tilled or otherwise weakened in spring  provides LOTS of functions in our rainy mild winters as an alternative to permanent mulch with soil benefits.  Many of our annual vegetables that are most vulnerable to slugs are weeds adapted to ground disturbance.  Lots of opinions out there on this topic.  Many I know use Sluggo (TM).  I stage early morning massacres (slugs become fertilizer... but don't let sensitive children watch).  No ducks, here.. I suspect you'd need a tightly choreographed system to keep the duck pressure high, but not mix them with the vege seedlings.  The heaviest damage is to crops like greens and peas where there are too many individuals to protect one at a time -- but the slug issue is not across all crops.  Without some kind of slug control in vulnerable species my losses are very high.  I cannot justify the cost of copper at my scale (around 200 linear feet of raised bed).

it is an issue, but I think what Steve Solomon objects to is using mulch in a mostly typical annual vegetable garden.  in my experience (Seattle, central and southwest Washington Cascade Foothills), things balance out after a break-in period.  that is, pest species proliferated early in my mulching career, but by resisting the urge to eradicate them and providing good habitat and food for the predators of those pests, the problem largely went away.  it isn't only the nasty critters that take shelter in the mulch; friendly critters hide in there, too.

if the only plants allowed to live are annual vegetables in orderly blocks or rows with no consideration given to supporting helpful species, chances are good that old Steve will be right about the pests.  he just lacks imagination, as far as I'm concerned.

so you might be discouraged early on, but if you hang in there you might have better results.  though others likely have different experiences than I do.  for my money, thick mulch works in the short term, but I prefer living mulch/groundcovers in the long term.

Thank you tel, that was my suspicion. Solomon's book is about using standard rows and raised beds for annual vegetable plots. I was hoping that the answer to my question would be that if I plan my garden right I will have a balance of birds and bugs that will keep any pests growing in the mulch in check.

Paul, do I understand that you remove mulch from your perennial garden before winter sets in? And that you then till it into your intensive annual beds? Does this work as some sort of compost? I'm also interested in your suggestion of using cover crops and ground covers instead of mulch. I plan to do this overwinter in unused annual beds anyways. Can you grow veggies in and amongst an established cover crop?

Sorry, so many questions...!

L8Bloomer wrote:
Sorry, so many questions...!

this would be a pretty dull site if folks didn't ask questions.

L8Bloomer wrote:
Thanks, Catch. We're in Duncan.

Have you left mulch in place over the winter? Was the pest problem worse the following spring?

I, too, am thinking of getting ducks. I love the sounds they make and hopefully we'll be putting a pond in as part of our design plan.

I didn't really the first winter (well I did, but I had used it pretty sparingly and actually tilled some of it in in the fall without knowing better). The slugs were worse the following spring, but it was also a very wet spring and I started a thicker mulch much earlier. There is a thick cover of straw on the garden this winter, but we've moved so I don't know what effect it will have this spring. I think a lot depends on the rainfall once it starts to warm up. Also, my garden there was a very typical annual vegetable garden in rows. The slugs seemed to know exactly where to move in. I assume having things more helter skelter would mean that even if they killed one section of crops, there would be another one somewhere else they might miss.

I did try a living mulch last year, but the clover very quickly overtook my garden and I tilled it all in and dug a lot of it up. I don't think I gave it enough of a chance though. It looked a bit messy/weedy to me, but honestly straw doesn't look all that much better really. I definitely want to move towards using living mulches instead of straw myself. I saw a reference somewhere to using strawberries as a living mulch, but haven't read much more about it. My daughter would probably be in seventh heaven if we had strawberries growing through all our gardens, so I want to find out more about that. Clover would be good too though as we plan to have chickens and I think they like clover.

I agree that the copper can be prohibitively expensive for a large garden. I wouldn't mind the cost if it were permanent, but from what I've read it doesn't actually last long before needing to be polished or replaced. My daughter's favourite animals are ducks, so I think ducks and some Sluggo applied sparingly near the areas that are hardest hit might be the way I go this year.

Paul Cereghino wrote:
I mulch in perennial systems, but all my mulch is seasonal, and eventually turned under in my intensive annual garden.  I have been experimenting with galvanized barriers as well, and believe they have an effect, but have not run conclusive trials.  A living cover-crop and catch crop, tilled or otherwise weakened in spring  provides LOTS of functions in our rainy mild winters as an alternative to permanent mulch with soil benefits.  Many of our annual vegetables that are most vulnerable to slugs are weeds adapted to ground disturbance.  Lots of opinions out there on this topic.  Many I know use Sluggo (TM).  I stage early morning massacres (slugs become fertilizer... but don't let sensitive children watch).  No ducks, here.. I suspect you'd need a tightly choreographed system to keep the duck pressure high, but not mix them with the vege seedlings.  The heaviest damage is to crops like greens and peas where there are too many individuals to protect one at a time -- but the slug issue is not across all crops.  Without some kind of slug control in vulnerable species my losses are very high.  I cannot justify the cost of copper at my scale (around 200 linear feet of raised bed).

For slugs, I use the old beer trick. I'm not sure how good it is on a larger scale, but it does seem to work for a garden. Afterwards, you can spread the slug fertilizer around for happy plants. Keep away from sensitive eyes, though.

I'll undersow clover (per Coleman's New Organic Grower) after the main crop is established.  I am most concerned with competition over water and so primarily use cover crops between crops, and try to get as much of the garden into a green manure over winter, but don't try to establish an annual crop into a strong perennial cover (though I will be experimenting with this, perhaps using the mulch as a disturbance during establishment of widely spaced crops).  I am interested in getting into winter-kill crops and how they may fill a nitch, particularly as a companion to garlic or overwintering brassicas.

My intensive beds (no framing, just trapazoidal in crossection...

   
____/-----\__/-----\____

...with a little rim on the edge to hold in irrigation water.

are surrounded by a boarder of permanent mulched sub-shrubs, strawberries, perennial onions, mulch plants, etc.  Which are in turn sorrouned by hedge, food forest or other more wild areas.

I also have a portion of pasture that I manage with scythe as a biomass input to the intensive garden, which I further supplement with imported manure and kitchen/chicken composts (also nutrient imports through shopping and feed purchase).

Mulch comes and goes and moves around in different thicknesses based on the crop and the season.  Sometimes it sits in a pile in the corner sometimes it is borrowed or returned to the boarder, sometimes it is composed of waste from another crop in a neighboring bed.  When it gets pretty mungy I'll bury it the trench as part of a double digging to further deepen soil (sort of like the english bastard trenching).  At some points, the mulch is like is a travelling caravan of spiders, beetles and other creatures. 

During spring there is 80% clear ground.  In summer around 50-70% of the ground is covered with mulch with the rest being slug sensitive winter crop seedlings.  By fall its ideally around 50% mulch and 50% green manure.  This patchiness is typically at around the scale of a 6' length of bed and I have around 48 of these 'units' right now.  We are developing a much weedier wilder garden for potatoes and three sisters and chickens.

My intensive garden is like a little patch of mollisol prairie, and I am the buffalo and the prairie dog.

I have been experimenting with moving crops into less managed environments but still obtain around 90% of by yield from this system.

catchthewind wrote:
I didn't really the first winter (well I did, but I had used it pretty sparingly and actually tilled some of it in in the fall without knowing better). The slugs were worse the following spring, but it was also a very wet spring and I started a thicker mulch much earlier. There is a thick cover of straw on the garden this winter, but we've moved so I don't know what effect it will have this spring. I think a lot depends on the rainfall once it starts to warm up. Also, my garden there was a very typical annual vegetable garden in rows. The slugs seemed to know exactly where to move in. I assume having things more helter skelter would mean that even if they killed one section of crops, there would be another one somewhere else they might miss.

I did try a living mulch last year, but the clover very quickly overtook my garden and I tilled it all in and dug a lot of it up. I don't think I gave it enough of a chance though. It looked a bit messy/weedy to me, but honestly straw doesn't look all that much better really. I definitely want to move towards using living mulches instead of straw myself. I saw a reference somewhere to using strawberries as a living mulch, but haven't read much more about it. My daughter would probably be in seventh heaven if we had strawberries growing through all our gardens, so I want to find out more about that. Clover would be good too though as we plan to have chickens and I think they like clover.

I agree that the copper can be prohibitively expensive for a large garden. I wouldn't mind the cost if it were permanent, but from what I've read it doesn't actually last long before needing to be polished or replaced. My daughter's favourite animals are ducks, so I think ducks and some Sluggo applied sparingly near the areas that are hardest hit might be the way I go this year.

If you can get slugs to crawl across open areas, I think that'll make it more likely that birds, ducks, chickens, etc. can pick them off. I have heard that spreading crushed eggshells around plants and on borders can help and deter them as well. But I had more success with laying beer traps for them and turning them into slug fertilizer or bopping stragglers with my shovel. And I think the idea of strawberries for ground cover is great. I have some strawberries in pots that are always trying to leap out and run amok with their runners. Harnessing their energy and explosive power as edible ground cover is definitely one way of doing things.

Hey pacific northwesterns,

This is my first post so i dont know if this is even in the right section, sorry if its not...is there a pacific northwest section?

I too am new to permaculture. I have been truly memorized by its potential, simplicity, beauty, harmony and so many more aspects...it represents everything I believe in, within so many different circumstance in life. I have been researching as much as I can on the subject (e.g. gaias garden, edible forest gardening vol II, sepp holtzer videos, geoff lawton's videos, bill mollison videos and so much more).

I am looking to buy around 20 acres in clackamas or multnomah county oregon. I was thinking that once i purchased the land, i would find a "professional" permaculturist to survey my land and work with me to design swales and terraces mainly, but also to provide me with some insight of certain  properties of my land and of the pacific northwest in general.

I was hoping you guys could give me some insight on what to expect in terms of soil quality. I know it differs area to area, but what are the general characteristics? I assume its very clay-like and dense, perhaps making root growth difficult for plants? If so, what are the methods you use to make your soil more loamy and aerated? Obviously adding organic material helps, so i was thinking of sheet mulching on the bank of a swale, and then spreading legumes and cover crops to fix nitrogen over the light mulch, and then after a season i could plant fruits and other crops. Would this help aerate and better prepare the soil?

Again, I am new to permaculture but i am just wondering what i can do to immediately boost the quality of the soil on my land. I really appreciate any help or insight on this matter. Thanks!

Jesse

Hi L8bloomer, thanks to the bump I just saw this thread--we're in Cow Bay!

I too was caught between Solomon and permaculture in my first year of serious big veggie garden growing.  I would like to work towards what Paul C. outlined to get the best of both worlds.  I started my garden with sheet mulching in the fall with a thick layer of straw mulch on the top.  In the spring, I pulled off the straw (and the slugs with it!) off the beds that I was ready to plant, and left it on those beds that were going to be planted later. 

Remember that you can mulch with just about anything; it doesn't have to be straw, which does attract slugs.  I mulched those spring beds with compost, and this year I'll do the same (or use manure).  I used straw mulch for transplants going out during the dry season--tomatoes in particular did really well with the straw mulch.  That may partly be because of using older transplants.

When direct seeding, I experimented.  Just pulling back thick mulch to seed a row was a disaster, but pulling off the mulch, seeding, and laying a thin scattering of straw back on top worked really well--seemed to keep the birds from disrupting the fresh beds.

We'll be getting ducks later this year, and we have chicks growing into chickens at the moment.  I think the secret there is not to let the ducks into the garden for maintenance, but to let them all roam freely during the winter and early spring.  This is when there's not much growing besides weeds, and there are MANY baby slugs and eggs.  Having the poultry eat the babies means fewer slugs during the growing season.  I also love the idea of the chicken moat, where the poultry is around but not in the garden, and work as patrol zone!

I also like the idea of a fall cover crop that become the mulch for the winter and is decomposed by spring, ready for planting.  I'll be working my way towards that over the next couple of years. 

I think what is clear, though, is that the true Ruth Stout lasagne gardening with thick layers of mulch and the soil never disturbed is harder to carry off in a climate without a serious winter kill season.  So I think the kind of shifting or strategic mulch approach works better here.

I'm still learning, though!  Good luck to you!

In this book Solomon states quite emphatically that you cannot use mulch systems in our climate because our winters are not cold enough to kill off all the pests that make a home in them over the winter. He claims that using mulching techniques results in pest overloads in a short time.

along with the overwintering pests, come the overwintering predators. wolf spiders, centipedes, and such love roaming the mulch for emerging pests. also the heavy rains in the PNW will compact bare soil too much.

All this said, I am playing with permanent herbaceous mulch in a border, and permanent woody mulch in the adjacent food forest, and and patches of herbaceous mulch in the woody mulch.  Mulch is so useful that it is worth pushing it until our little brains begin to understand.

wuwei7 wrote:
I was hoping you guys could give me some insight on what to expect in terms of soil quality. I know it differs area to area, but what are the general characteristics? I assume its very clay-like and dense, perhaps making root growth difficult for plants? If so, what are the methods you use to make your soil more loamy and aerated? Obviously adding organic material helps, so i was thinking of sheet mulching on the bank of a swale, and then spreading legumes and cover crops to fix nitrogen over the light mulch, and then after a season i could plant fruits and other crops. Would this help aerate and better prepare the soil?

I don't know those counties specifically, but I was raised in the Seattle/Tacoma area.  Soil around here is usually pretty rocky on the hills, though valleys can be quite rich (as in Puyallup).  I've usually had to deal with soil barely 3" deep, and that was usually pretty full of clay.

I've been inspired by Ruth Stout.  I keep my garden under thick straw mulch (6-8").  I don't claim to be a great gardener (too lazy), but I know deep straw does keep soil moist and soft even without watering, even in the hottest part of summer.  I haven't had unusual problems with pests. 

One garden I started was bare dead pale rocky earth about 4" deep before hitting hardpan, scraped open by bulldozers and without an earthworm in sight.  I deep mulched it throughout the summer, then overwintered in crimson clover and rye.  By spring the soil was crumbly and black, full of earthworms, and not waterlogged or impenetrable like my neighbors'.

Oh, yeah, I also made hillbeds byscraping out what little earth was available from the paths and putting them on top of the raised beds.  That deepened them to a decent 8" or so.  But it was the mulch and the green manure providing habitat for earthworms which made the most difference, I'm sure.  It took the soil from just there, to really wonderful.

I traded time for work, because I'm not in a hurry.  For me it has worked out very well.

I love straw mulch it's easy to work with and I think it works well for compost when I mix it with grass clippings.  Easy to haul in my car and store.  Love it even more between beds for pathways. The dogs will stay on the path better and in summer they love to nap on in.  Napping keeps them from stealing from the garden.  When rainy keeps the mud off of the feet.  I look at it this way slugs are like the rain here in the PNW you can't really get rid of either.  I have tried everything I could think of to deal with the slugs.  The very best so far is hand picking. 3 plastic grocery bags one to cover your hand with so you can pick the slimy cusses up and the other two to put them into.  tie bag shut and dispose or feed to geese or whoever else will eat them.  Sometimes feeling guilty over taking lives I will walk them way down to the bottom of the forest and set them free.  Over time my slug population / damage is minimal. So minimal in fact that sometimes I forget there ever was a problem and am shocked that plants have been eaten.  Now that's results!  Just so you know the first slug hunt  I got 3 yes 3 bags full now I only have about 10-15 slugs total every third day.  Also have rock piles around I guess snakes live there and will eat the slugs?  Straw or other mulch causing slug problems don't know in my case the slugs were worse where there wasn't any mulch. I live in the Columbia river gorge. My strawberries seem to get choked  out by weeds very easily so they have their own special place.

Danelle, I agree.  Straw doesn't seem to make slugs any worse.  It may even be beneficial for slug control.  Slugs don't seem to proliferate so badly when there are plenty of earthworms.  I don't know the connection there, though. 
Also, rock piles are a great idea!  I love seeing some garter snakes in the garden because I have seen them eat slugs.  SLUUURRRP!!

I'm going to set up a rock pile in my community allotment soon.  Snakes need their sunbathing space.

CrunchyBread--what an inspiring story!  I'm convinced that cover crops are miracle workers.  And all of you are right on about the spiders and other predators that thrive in the straw cover.  We did have LOTS of snakes last year too, which I think made a huge difference to the slug population.

You've all inspired me to keep trying!

CrunchyBread wrote:
Danelle, I agree.  Straw doesn't seem to make slugs any worse.   It may even be beneficial for slug control.  Slugs don't seem to proliferate so badly when there are plenty of earthworms.  I don't know the connection there, though. 
Also, rock piles are a great idea!  I love seeing some garter snakes in the garden because I have seen them eat slugs.  SLUUURRRP!!

I'm going to set up a rock pile in my community allotment soon.  Snakes need their sunbathing space.

I destroyed an onion today because it was covered from top to bottom with slugs.  It isn't that the control or make worse, none of the mulch things matter with regards to slugs.  What we all cheerfully need is more frogs.

SW Oregon Coast, zone 9, 43 degrees N Lat.


I also suggest you lucky people in the Vancouver area swing by Orcas Isle & check out the Bullock Brothers Homestead.

Oh my gosh I just love frogs! How ever when we had a small pool the frogs just went crazy. It was so loud that inside the house with the windows closed you could not hear the tv stereo phone or people talking. it was LOUD! So the pool had to go. Would love to have a pond but that would have the same effect. So will just have to rely on hand picking slugs and inviting more snakes.  Will keep using the straw mulch haven't tried green or cover crop yet do sprinkle cut grass lightly from time to time.  We could all make some major coin if we can figure out what part the slugs do play. I have seen then eat dog poo but that would be another topic.

Just a thought I can't see how bringing in more life into the garden would be a bad thing. I will try some cardboard that has been injected with mushroom then put that out as a mulch/compost/ mushroom garden.  They grow good in straw too

Nice to see some more discussion on this thread!

Funny enough, I recall last spring when we first moved here that when I walked the dog, as soon as I left the property I'd see slugs everywhere. But I don't recall seeing quite so many on our property. We do have a huge frog population here, judging from the sounds of the spring peepers, and that my kids caught a few of them over the summer (released them after a few minutes, of course). And we have lots of garter snakes. Must be because our soil is so very rocky and we have piles of rocks everywhere from me trying to clear them away from seeded areas.

It's hard to say what your soil will be like, Jesse. I thought clay soils were standard fare here but I did soil tests (shake the jar) and found hardly any. A local cob builder confirmed that folks in my 'hood have to bring in clay to make cob.

Our soils are also very, very rocky. Beautiful topsoil full of bugs and life, but oh the rocks! It's apparently the fault of the glaciers that passed through here, and as we are up higher (150 m) we don't have river valley flooding to give us a good layer of rock-free soil.

crunchybread that is so cool you saw a snake eat a slug. I have never seen that before. I don't sees snakes that often but I do find their skins. We have a big fat one snake that is that lives under the front steps.  Lots of straw mulch and a pile of rocks with brick boarder. Don't know that it's the same one but every year I find a skin in the same spot and it't bigger.  never ever have found a slug in that bed.

Slug Help:  Lots of topics within this thread but if you are looking for an effective slug control check out Slug Shields.  I use them with success and I like the fact that they last a long-time and are non-toxic.

About those beer slug traps. Make sure raccoons don't have any access to them. I've had them pull the traps out. I didn't see it happen, so I can't swear they DRANK the beer, but I know from paw prints that's who was doing it. Raccoons, now there's a PNW garden pest more devastating than slugs!

I've had my garden here in Portland, OR mulched well with mostly straw and misc plant matter from the garden for 3-4 years now.  I swear by it - retains moisture in the summer and reduces evaporation, provides good habitat, makes for a good spot to tuck under organic matter for decomposition since even if the top of the straw is dry it's almost always moist underneath, stops the compaction from rain, slows runoff of rain and nutrients, and eventually breaks down into more compost.

I propose to you to consider that the forests around here are properly mulched! 

one suggestion i haven't seen yet is to mow a strip around your garden and keep it mowed. Slugs dont like to cross open ground. This will keep newcomers from coming into the garden. Of course, this isn't all that effective unless you can effectively eliminate slug populations because otherwise they just continue breeding inside your garden.