An initial tilling will get the compost mixed into the soil quicker then just putting it on the soil and will make that soil more workable. The cardboard, or newspaper, will act as a block and keep any unwanted plant growth, aka "weeds", from growing in the soil.

Agree if it is heavily compacted then till it. The compost can be spread on top the soil, not the cardboard or tilled in. Your choice but tilled in is better IMO. THEN lay down the cardboard on top. To secure the cardboard I cover it with a layer of straw or hay. Looks better too but it is optional.

Dave

I did the whole cardboard thing...it works good. However, over a period of 2 years it led to a population explosion of pillbugs, earwigs and other nocturnal ground dwelling pests. I tried to be patient and wait for the predators to balance things out but it never happened. Once I pulled all of the mulch out of the garden their numbers declined significantly. I now work all of my compost into the soil.

I tilled the year I did the cardboard and mulch. My lot is very level, maybe 6"-8" fall anywhere. So I used my garden beds as a drain for that part of the yard. My soil is clay. So I have 2-140'x4' beds with sloping surface draining.

The first year I had minimal leaf growth as I didn't add anything other than horse manure after creating my beds. In fall I mulched heavily with oak and pine leaf(thanks neighbors). Last year I had great leaf growth, no horse manure. This fall I again mulched heavily(6"-8"). I expect good leaf and fruit growth again this year.

Yes, the pillbugs and earwigs are here but they do minimal damage.

I have bindweed in my garden and it comes up every year. I have been digging it out (a few inches deep) over the last year, but it keeps regenerating (the roots can go up to 10 feet deep). I was hoping that cardboard mulching would help with that and add organic matter to loosen up clay soil. Having compost on top of the cardboard would make it decompose faster. I had not thought of the bugs the cardboard would attract.

A little bit googling turned up that one can use diatomaceous earth to control the bugs. So maybe a sprinkling around the base of each plant with keep pill bugs and earwigs underneath the cardboard.

The new plan is:

1. Till in half of the compost (most likely horse manure)
2. Lay down cardboard
3. Top with other half of the compost (may be 1")

half of the compost (most likely horse manure)

Just for clarification since they aren't the same thing and I thought we were talking about compost above. I'd use the horse manure on top the cardboard. It will help prevent, or at least slow, the build up of soil salt levels when using manures.

Dave

Soil is made of the mineral (the sand, silt, and/or clay particles) and the organic matter. Most of us have a soil that is either sand or clay, although some near rivers may have silty soils.
Clay soils, because the way these particles are made, tend to be compacted and hold both moisture nutrients and not allow them to be released to plants growing in that clay. Organic matter seperates those mineral soil particles, and changes the soil enough that the moisture and nutrients are released, and allows plant roots to move about in search of moisture and nutrients much easier. If organic matter is placed on clay soils it will, eventually, be incorporated by the Soil Food Web without tilling while tilling will mix that OM in immediately and start the soil improvement much quicker.
I would be more concerned about what animal manure would do to the soil pH then about any "salts" that manure might contain. Keep in mind that chemically a salt is anything with sodium in its name and may, or may not, be something that is not a problem in soil.

I need to cover a fairly large space with cardboard, and could use some tips on obtaining it. Walmart used to be my best source, but they're recycling their big boxes now. I'm glad they're being responsible, but I like my kind of recycling too. :-) I've called a couple of appliance stores, but their responses were vague at best.

I'd appreciate your suggestions--thanks!

I get cardboard from the recycling drop off location. I take my plastic and glass, and leave with a truckload of cardboard.

Thanks, Clayfarmer. I had high hopes for my recycling center, which is about 30 miles from my home. But when I dropped off my stuff last week, I found only a couple of pizza boxes in the dumpster. It's a roll of the dice, I guess . . . probably the next day I could have found lots more.

Cardboard is also known to hang around (presumably in bad company) behind convenience stores as unbroken-down boxes in recycling dumpsters, grocery stores (baled), and big box stores that don't have a roll-off type compactor.

Thanks, Evil (sounds better than Cold). I have to go to town today, and I'll poke around.

Make sure not to take the cardboard collected from behind convenience stores, etc inside the house. It could have roaches in it.

Thanks for the warning about the increase of pillbugs and earwigs. I did think about that, that this kind of moist, layered area is perfect for these little critters (including slugs and snails). Glad to hear someone's personal experience about that.

I'm not sure if my attempt to amend the soil with this layering method could lead to a different issue later like that but I'll be aware of it that I caused it!

What are the chances cardboard with a topping could kill off tough stuff like thorny vines, English ivy, poison ivy and other tough perennial weeds? I am renovating a long neglected yard.

I plan to weed whack it first, leave the residue in place and then go with cardboard with mulch on top.

Just afraid the bad guys will resurrect after this treatment when the conditions suit them. It's my nightmare! Please comment if you've had experience with this challenge whether it was good or bad. Many thanks!

Just afraid the bad guys will resurrect after this treatment when the conditions suit them

They will ... which is why you will need to patrol the area and jump on any sprouts you see before they can get very big.

I would weed whack them***, water them thoroughly to encourage growth and immediately cover them with the cardboard and a THICK layer of mulch. If you don't have enough to do the whole area, start on one edge and do a really good job of it, expanding the treated area as time and materials become available.

they'll waste a lot of energy trying to send out new growth.

Just keep whacking the stuff you haven't covered up.

*** actually, I'd whack them, encourage fresh tender growth and spray them with glyphosate to kill the roots, and then whack them again and do the cardboard and mulch, but this IS the organic forum.

Does cardboard contain unnatural glues?

Keep in mind that anyone that would advocate the use of glyphosate on an organic gardening forum is not an organic grower. It may well take several years to kill off these ivies with just cardboard and a mulch. Digging up the roots is more effective.
ju1234, cardboard may well have glues made from synthetic products today, since finding glues made with, say animal hides, is much more difficult now.

I'm not capable of digging up the roots. Maybe a double layer of cardboard under the mulch will make up for the lack of root digging.... at least I hope so.

Then I'm prepared for a rousing game of whack a mole (weed) for years to come.

I second the idea of whacking the growth off, watering freely, and letting the new growth develop before laying down cardboard. I know from experience that for me, this was a much more effective start than just laying down material over weeds. I don't label myself as an organic grower because of all the legal associations with the name now, but rather as a natural grower. For me, this means that I try to avoid chemical treatments unless necessary. For most people I interact with, this is just as good a label as organic, and it removes all the complex certifications and such that the law implies. For me also, roundup would be a necessary treatment, and I happily use it to avoid countless hours of back-breaking and frustrating weeding. The roundup has virtually no even short term effects on the environment I am growing in, and no long term effects. My time is too precious to be spending time needlessly weeding; there are enough weeds around that I already do have to pull by hand. After whacking, watering, rounduping, and then maybe watering and rounduping once more, I put down the thick mulch. It is really amazing how few weeds are left. In one quite large area this year, I think I had 3 or 4 total come up--maybe from seeds in the wood chip mulch.
Renais

I understand your desire to use Roundup, but please be aware that it isn't as innocuous as Monsanto would like us to believe. From a Reuters article published in May 2014:

But environmentalists, consumer groups and plant scientists from several countries have said in recent years that heavy use of glyphosate is causing problems for plants, people and animals. They say some tests have raised alarms about glyphosate levels found in urine samples and breast milk. In 2011, U.S. government scientists said they detected significant levels of glyphosate in air and water samples.

ju1234 - "Does cardboard contain unnatural glues?"

Define "natural" ...

Most cardboard has a biodegradable glue, EXCEPT for boxes used in wet environments: beer boxes, fish boxes, etc.

Keep in mind that "natural" does not necessarily mean acceptable to organic growers. Arsenic is a natural substance.

I do think it is courteous to avoid the topic of chemical herbicides and pesticides when posting on the Organic Gardening Forum-- it's a "when in Rome" kind of thing. Otherwise it's kind of like offering roast beef recipes to vegans ;)

So glad I came to this thread! I was thinking I would have to lay heavy black plastic down for months to try to smother the dang tough stuff before I could even try cardboard and mulch. Now I know I don't have to thanks to you all.

I can't wait to start using all the cardboard I've been stockpiling in the house and garage in addition to the saved newspapers and brown grocery bags. With my own pine needles & chopped leaves on top, I haven't bought mulch in over 20 years. Best of all, there's 12+ inches of nice rich soil full of happy worms where hardpan soil used to be. Thanks for the quick responses and good information!

Thanks for the helpful info, everyone. I really appreciate it as a new homeowner and novice gardener.

We have a very large backyard that was completely overgrown. We've cut everything down/back, and now want to not lose our gains before being able to set in some plants or landscaping next year.

My question as we're heading into Fall is, what time of year should I do the cardboard mulching ? I live in the Pacific Northwest, and we'll get good rain until April or May. Part of the area will have standing water for a couple of months during late winter and early Spring. Should we lay cardboard this Fall, so nothing comes up on the Spring? Or would it be useless with all the water we get and we'd be better off to wait until the Spring. Maybe laying the cardboard in April and then planning on planting around June or so?

Thanks again!

When to mulch is always somewhat of a dilemma so I use the criteria that if I have actively growing unwanted plants I mulch. That may be now or it may not be until spring.
There are, generally, two reasons for water standing on soil, poor drainage or a high water table. The drainage issue can easily be resolved by adding adequate amounts of organic matter to that soil while the high water table requires much more work over a much wider area. If that standing water is due to a high water table raised beds are a solution, although raised beds are used when soils do not drain well because some think that easier then adding adequate amounts of organic matter.

Kimmrs is so right about the timing! Depending on where you live, there can be unwanted plants that surface year round whenever there is a mild sunny day. The other thing cardboard will do is decrease the light available...which hopefully discourages weed seeds from germinating.

Sharon, I would encourage you to lay the cardboard & mulch now when the ground is the clearest you can get it. Even the wet parts if anything grows there.

Yayy! Thanks to this thread, all of the cardboard is out of my house and on the ground with mulch on top. I waited until we had a good rain so the soil was moist and wet down the cardboard as I went along. WHAT A RELIEF! I'm loving seeing no green where I don't want it!

The only part left is the one I dread the most: a big section where English ivy is rampant. I'm going back through this thread to see the approaches. I'd love to just cut it back enough to be able to lay cardboard instead of trying to dig it out first. But I doubt I'll be that lucky.

Rightly or wrongly, I didn't till the compacted areas before laying the cardboard. It may be several years before many of the areas are planted, especially landscaping the borders surrounding the yard [$$$$$]. I'm going to till when & where I'm ready to plant and can work in the compost & other amendments the plants need.

But environmentalists, consumer groups and plant scientists from several countries have said in recent years that heavy use of glyphosate is causing problems for plants, people and animals. They say some tests have raised alarms about glyphosate levels found in urine samples and breast milk. In 2011, U.S. government scientists said they detected significant levels of glyphosate in air and water samples.

Somebody above quoted the above excerpt. I hv questions: 1) where were tests conducted? Where the mothers tested farmers or regular soccer moms? I don't want ANYBODY unduly exposed but it makes a diff and may be unnecessarily alarmist.

We hv enough real threats, do we need to read a bunch of what if scenarios? I am already scared enough, how about y'all?

Back to topic, I use cardboard when establishing new beds only and highly recommend. Reduces weed population but you have to keep up with light layers of mulch in subsequent years, else weeds will regrow, especially in moist and sunny areas. Has been extremely easy to get boxes at WM. Just walk thru store and spot a worker restocking shelves. They usually have boxes they've unpacked close to them and they have always gladly allowed me to take what I want (less for them to haul to back of store )

I just mulched a large area this weekend using cardboard and free wood chips from the village. I first used the weed wacker to cut off all the weed/grass to the ground as much as I could. Then I placed a single layer of cardboard and then 3 to 4 inches of wood chips. Hopefully this will kill of the creeping charlie underneath.

If you have access to mulch or wood chips, I would recommend putting the material down now so that it will give you a 6 month head start.

This post was edited by dev_garden on Fri, Nov 14, 14 at 11:07

Cardboard + chips is effective, but not practical as widespread and/or regular application.

Here is for the real gardeners:
Cardboard/chips should be used as a *temporary* part of the initial plant installation/establishment/weedkill process (right after you amend your soil with well-rotted carbon and other mineral/pH modifiers). Progressing forward, plants should do the work of mulch (I like to encourage the clover). Your "crop" plants should be competitive enough to at least earn a spot on the podium (I'm looking at you, vegetables!). I keep the living mulch hoed away from weak/young plants (a carefully sharpened shovel makes a wonderful hoe in addition to its digging/weeding value). Your soil is a petri dish; keeping it clean is futile/unnecessary/less healthy. Nature doesn't need alot of help to build healthy soil; mostly just needs to be left alone.

Cheers,
B