Mulch is best on top of the ground. What kind of material is it?

Generally avoided. Potential problems and nothing gained.

Dave

I'd call that in situ composting. It works, assuming the mulch isn't composed of large chunks that won't decompose completely over the winter. I frequently dig in uncomposted shredded leaf mulch at the end of a season, if I haven't composted it yet.

Depends entirely on what the mulch material is. Would disagree on the "nothing gained" concept.......it might provide considerable benefit. But that will depend on the mulch and other soil conditions.

Of course mulch is on top of the ground. But once the season is over I'm not sure if I should mix it in or take as much out as possible. I'm sure it depends on what material, but I guess I'm asking about pine bark, or anything not leaves/grass/newspaper.

Pine bark is one thing.........anything not "leaves/grass/newspaper" opens things up for a whole lot of other stuff!!

Generally I have no concerns about any wood type mulch being mixed into the soil other than it can temporarily tie up nitrogen availability until it decomposes. But that's easily addressed with a little bit of high N fert. Wood or bark mulches will help to aerate and lighten heavy soils and can help with water retention. And they will eventually increase the fertility of the soil. I'd probably exclude sawdust from that category as it can often contain glues, adhesives or other chemicals that could be detrimental.

IMO, there is no need to remove any organic mulch. You can just leave it in place to help control whatever weeds may appear through the winter. Rake it away to plant in spring and then put back into place. You may need to refresh a bit. I also have no concerns about mixing or incorporating pretty much any organic mulch into the soil either. All will help to stimulate soil biology and increase fertility although there may be some side effects one should consider......such as the N tie up.

I'm a bit surprised other posters advise against it and I'd be interested in knowing why. An organic mulch is just a form of soil amendment if used in this manner........

I agree that uncomposted material can tie up nitrogen, which is why mulch that is dug in needs to be thoroughly degraded by the next planting season. Large chunks of wood won't be so degraded. Pine bark? I guess it depends on whether it is shredded or not. If it isn't shredded or old mulch that isn't already heavily degraded, I agree. Just leave it on the surface, and rake it aside for planting.

I assumed wood chip mulch based on other posts when I answered above and I discouraged mixing in wood chip mulch just for the reason gardengal posted - mixed in it binds up nitrogen. Sure it decomposes eventually but mixed in can cause problems that it doesn't cause if left on top of the soil - thus my comment "nothing gained" - as any benefits from it work just as much or even better if left on top.

So my question to the OP would be why do you feel you have to do either one?

I agree that there sure isn't any reason to remove it but there is no reason why it has to be mixed in either. If you are wanting to till or turn the soil then just rake the wood chips to one side into a pile and do what you have to with the soil then rake it back into place. Or you can let it decompose over the winter in the pile and then re-spread it in the spring.

Dave

You're all assuming I grow in the ground . I grow in pots so I cant rake it. I ask because if I mulched my tomatoes I would have to take it all off the next year so I can turn the soil and add new amendments when I'd rather just mix it in with the amendments.

Again, wood chip mulch binds up nitrogen while it is composting. Once it is composted, it adds a bit of nitrogen, and certainly improves the soil texture. So yes, not clear where you are, but if you're going to put your garden bed to bed for the winter, fine wood chips will all be cooked come spring (mixed metaphor!) If you're going to put in a winter crop, it would not be smart to dig it in.

We all assume you grow in the ground because you didn't say otherwise.

If you grow in pots, you can certainly scrape the mulch off with your hand. If you're growing in containers with soil-less mix, what's the mulch for? Adding compost or compostables to container mix isn't necessarily constructive. Also, in situ composting doesn't work well in containers, because the soil will get very cold in the winter, which will slow composting dramatically.

OK - container soils are a whole 'nuther ball game and much different practices and materials apply!! Most container gardeners do not mulch.....really very little need to compared to the reasons for mulching inground plantings.

If you are making up a new mix (container soils should be replaced annually), you can certainly add the pine bark mulch as part of the soil mix.......it is a common ingredient in many container soils.

I have a similar question - this year I am planning to work my straw mulch into the soil in the fall instead of growing a cover crop.. good idea or bad? In ground raised beds..

Shijitake, if your mulch is a fairly fine grind wait until early spring then dig it into your pots. Work in your soil amendments at that time for nitrogen, etc. These types of dry amendments take a bit of time to work. This summer I have been experimenting with incorporating various grades of pine bark mulches into soil. This study was forced on me due to soil delivery to a new community box garden that was so sterile even weeds would not grow. I did not want to use city compost so I turned to using the bagged pine bark mulch known as soil conditioner. Wonderful stuff. Also wonderful as a surface mulch for growing in pots. Usually only sold by large nurseries. But even with all types of amendments to this combination I was not seeing the results I wanted. So, I reached back into my old timer's memory and added 5# of granulated sugar to the mulch/soil/fertilizer amended combination in each of four garden boxes. In four weeks the result was startling! Seedlings that had put on no growth suddenly came to life. Tomato plants are still growing at about 8" a day. Foliage is clean and vibrant green. Ditto all other plants are performing well and producing abundantly. This success is due to the known fact that sugar encourages soil bacteria. Those beds to which I did not add sugar are very unproductive.

So, I encourage you to work a cup of sugar into each pot as you incorporate your mulch/amendments into potting soil. Some will disagree. So be it. Just try it, please.

What one would add to inground soil to encourage the microbial life and activity really has no relevance to container gardening. Because of its primarily structural ingredients - very little that is fully decomposable - there are minimal populations of soil biology. There is nothing in the mix to support or sustain them. This is why dry or granular organic fertilizers have minimal effectiveness in a container situation. There are simply not the populations of microbiology present to effectively convert the material into plant usable forms.

I can't imagine adding sugar to a container potting mix would do much more than attract ants.

Sugar encourages bacteria, but not necessarily the bacteria you want, including bacteria that will infect your plants. It's a good way to reduce nitrogen in your soil, because of all the (unconstructive) bacteria you're feeding. In fact, that makes it a good herbicide. Many use it for weed control. Definitely don't sprinkle sugar around plants you want. It interferes with the plants abilities to produce their own nutrients. Not sure why you saw success, but it certainly wasn't because you had more bacteria growing. This is all well understood, and backed up with research. But people love cheap magical powders. Epson salt is another one of those magical powders. Be sure to say an incantation when you apply. When you "just try it", just be aware.

As to mulch in soil, digging in a green cover crop will add nitrogen. Not so much from straw. But both will improve soil texture. But again, don't do this just before planting.

The OP has clearly stated that he/she is dealing with containers. Not much of what has been offered or addressed here pertains to containers so really has no application to the OP's question.

I was referring to the question by Hrib, which, it is true, in retrospect, doesn't pertain. Sorry, I should have been more specific.

Why wouldnt container users use mulch? If anything container soil needs it more than ground to keep moisture right?

As for microbiology, there are definitely some in my containers because I use espoma tomato tone which has beneficial bacteria.

"Why wouldnt container users use mulch? If anything container soil needs it more than ground to keep moisture right?"

Not necessarily. That would all depend on which of the many different methods the container grower waters and feeds their plants. And in most cases the canopy of the plant itself shades the soil. But that is neither here nor there. One could just as easily ask why anyone would try to grow tomatoes in containers? And there are many different answers to that question as well.

"As for microbiology, there are definitely some in my containers because I use espoma tomato tone which has beneficial bacteria."

True, well documented to be in very small amounts, limited in nature, and quite short lived in containers. Ample research is available on the benefits of using pre-digested liquid nutritional supplements in containers vs. dry granular ones.

Honestly, none of these are new questions to us. All have been discussed here numerous times by many people in great detail and often include links to various supporting research. Point is, there is no one single correct method but there is consensus as to what works best and what doesn't work well.

So when that consensus differs from your POV it pays to have an open mind rather than just disputing the info given you in your posts. Why not first use the search tool to pull up those many previous discussions on these issues and browse through them?

Dave

Most potting soils are specifically made to hold moisture better than garden soil. But it seems to me that if maintaining moisture in your containers is problematic for you, can't do much better than to lay an easily removable permeable cover on top of the soil. Paper? Plastic with holes? Those are tricks that are hard to do on open ground because the area to be covered is larger. Why bother with mulch on a container?

Now, if you use a container mix that has organics in it, and just about all do, and especially if you add something like compost to it, in principle you can get some bacterial activity going in it. Soil bacterial activity is useful for (1) degrading the organic matter, releasing some nutrients and (2) doing nitrogen fixing. But in principle, if you apply fertilizer to your container, and you always have to do that. neither of those functions are necessary. Bacteria don't add anything that fertilizer doesn't. Fertilizers with added bacteria don't make a lot of sense to me.

Digdirt, because I've tried before and the results come up with all kinds of things I didn't ask.

Daninthexdirt, it makes sense because you want to add bacteria to break more down faster and make the nutrients available. Its organic granular fertilizer I use. Also I use organic soilless mix from organic mechanic.

Comments above are just what I expected when I posted my thoughts about using a bit of sugar when incorporating mulch into container potting soil. No, it does not attract ants. No, in my experience it does not impede this and that. This is a method I have used for many years. Today my potted tomatoes, treated to a bit of sugar, are growing in daily temperatures mostly above 90 degrees and pushing 100 often. In this heat I have them growing in dappled shade where they continue to be healthy, bloom and set fruit...and from experience, will continue to do so. We each have our own 'ways'. This is mine written as a suggestion to shijitake to trial.

What kind of tomatoes do you have that are growing in daily temperatures mostly above 90 degrees and pushing 100 often that are actually setting fruit? A lot of people would be interested in that. But as to tomato plants just growing in that heat, no sweat. I do that routinely.

BTW, it's commonly understood that adding sugar to soil encourages bacterial activity. The bacteria eat the sugar, and then they're gone. The assumption is that hey, when the sugar is gone, they'll still be hungry, and chomp on soil organics. Doesn't work that way. The chompable soil organics support a population of bacteria that was likely already there. But again, sugar will certainly decrease plant-usable nitrogen content of the soil. Adding sugar is what you do if you've over-fertilized.

I agree that added bacteria might incrementally allow the soil to break down organics faster to make nutrients available. My point was that if you're adding nutrients, in fertilizer, as you're adding bacteria, why is it important to add bacteria? Maybe the fertilizer you're adding isn't really that potent chemically, and it needs help? Again, it just seems a little strange. But bacteria colonize suitable sites pretty quickly, so if the soil was a suitable site for bacterial growth, they'd probably be there already.

Yes, because the fertilizer needs to be broken down just like the soil. As I said, adding bacteria would break down the fertilizer faster. Adding quicker to eat food allows for faster bacterial increase in population. Why have 100 worker ants when you can add another 900 and get work done faster? Why not give bacteria easier to eat food so they can multiply faster? Why wouldn't you want a much larger amount of bacteria than you already have to make more nutrients availabe to your plant?

You need more than just bacteria to break down organic matter - you need a whole host of microbiology and in quite large numbers to accomplish this efficiently.

Applying fully organic practices to container gardening is usually less than entirely successful. To maximize root development and provide the necessary rapid drainage and proper aeration, the best container soils contain minimal organic matter. The reasons for this are extremely well researched and documented - the more organic matter included in the mix, the more rapidly drainage becomes compromised as the stuff continues to degrade and the finer the particles become as a result of this degradation, the greater the loss of porosity and therefore aeration. The perched water table rises and the potential for root rots and other issues proliferate.

Because it is very difficult to establish and maintain sufficiently large and diverse populations of soil microbes in a well functioning container soil mix, the use of any dry or granular organic fertilizers is essentially a waste of time and effort. They do not get broken down efficiently and most are wasted and your container plants wind up being deprived of the nutes they require to grow well and produce flowers and fruits. You can make some headway using predigested liquid organic ferts but few contain all the necessary macro and micro nutrients to keep plants happy and healthy.

It is really pretty simple. If you want to adhere to organic gardening principles AND have a successful harvest, plant in the ground, where these principles make sense and function as intended. If you want or need to grow in containers, then you will be most successful with a well designed and durable (non-decomposing) soil mix and a broad range chemical fertilizer......something like one of the Dyna Gro products. You cannot rely on the same functions and methods with containers.

It really doesn't work both ways and the science is there to support it.

Why? Why? Why?

Simple answer - because soil bacteria don't work that way. Do some research into 'soil food web' for starters.

There are a lot of faulty assumptions underlying most of this discussion and your other posts as well. Rather than accepting that there might be a kernel of truth to the opposing points of view, that some of the readily available alternatives suggested might work better, that further research on your part might be worthwhile, you only seem interested in justifying, nitpicking, and defending those faulty assumptions of yours. That's your choice. But it is a waste of our time trying to help when one isn't interested in anything but their own preconceived notions.

Moving on.

Dave

PS: and if you want to use sugar in the soil at least use unrefined raw sugar or molasses so the bacteria can actually benefit from it

Um, Dave. Sugar is sugar. Unrefined sugar has very tiny amounts of micronutrients that, if you're adding to soil, are already there in abundance. You add any sugar to soil, and bacteria there will gobble it up. The question here is whether they gobble up anything else. I suspect you can make your own unrefined sugar by taking highly refined sugar and adding a tiny bit of soil. Sound tasty?

You dissolve highly refined white sugar in water, and make it dilute enough, and you'll cultivate an abundance of bacteria. Of course, a high concentration of any sugar will kill those buggies, which is why sweet preserves can last forever.

Again with the assumption that I am "justifying" everything I think! I ask why why why so that I can get more details and information on what I am asking about. That is the point of why I am even here. Should I not ask why? Then how do I learn anything? So if I ask why about anything, I seem to be just justifying what I ask. Yes, I can experiment, but that takes a lot of time and money that I don't have. Why experiment when I can learn from others? Ever heard of learning from other people's mistakes or experience? Everyone here is disputing each other, not just me. Are we all scientists and researchers? No. We have differing opinions because of our different experiences. And that is what I'm looking for, details. My questions to you may sound like questioning the poster, when they are real questions looking for more knowledge. Would I really come here just so I can dispute what everyone says?? That is a waste of my time as well.

I am allowed to give my own opinion as well, as I am part of the discussion. I may be a novice in tomato growing, but I am not an idiot. Everyone told me the previous year when I planted tomatoes on grass, "why would you do that?", "you set yourself up for failure". I already said so many times that I had so many and didn't want to throw them out. So what should I have done? Tear them from the ground? And in contrast to what they said, the tomatoes grew just fine and gave me a nice extra harvest. They even TASTED better than the ones in the pots. Many of them were nasty or ridiculed me. And when I had something to say about it, everyone had to attack me. What was I supposed to do, just let them step all over me? Just because I'm new here or new to growing tomatoes?

I am taking what everyone is saying into account, and if I ask questions or give input, it's what this forum is about. Everyone can learn from everyone, novice or veteran.

For one thing- I do have to agree that nitrogen would be "bound" when the mulch is decomposing, although not so much bound as it is used up in the decomposition process and leaves little for your tomatoes. Look up composting. You need to add nitrogen for it to work.

To daninthedirt, it doesn't make sense to him for bacteria to be added to soil as there will already be some in there, when to me it makes sense. As gardengal said, in pots they do not last. So replace them with new ones. Why sell granular fertilizer without something that will break it down?

gardengal, what you say makes sense, but I would think that the decomposition you talk of would take many months, whereas I only have a growing season of 5 or so. Bacteria=microbes. I use them interchangeably. I wouldn't think viruses are there helping the plant, probably not germs either, unless they do? Real question, not disputing you. I say this because I *do* grow in containers, with organic soil-less mix, and organic fertilizer, and my plants are very vigorous and healthy. I have been for the last 4 years and I haven't had any problems with growth and health.

If all you are growing are seasonal plants, like the tomatoes, you might be able to get away with it. FWIW, plants can grow in anything for a limited amount of time - pure water to pure sand and everything in between. And without benefit of any fertilization. Do they grow as well or as productively as they would in a proper soil and with routine fertilization that is efficient in its delivery? Arguably not but it may not be very apparent from just a passing glance :-))

However, I grow permanent plants in containers as well - trees, shrubs, perennials large vines and perennial edibles (raspberries, etc) - and for any long term container growth, any organic matter in the mix is highly problematic. It collapses and breaks down very rapidly....even in a single growing season....generally due to the heat and moisture the containers receive. Which is why it is highly recommended to replace container soil at the start of every season.

btw, this is not just my opinion. It is a highly researched and studied issue and I am only offering you the benefit of my education and experience. And I am attaching a link that will give some additional information on the diversity of soil fauna - bacteria is great but it is not the only soil organism that is helpful or necessary and it alone will not complete the job of breaking down OM into plant usable nutrients. Soil Microbiology - A Primer

It is often difficult to get one's head around the differences in growing in containers compared to growing the same plants in the ground. The philosophy, methods and applications that one would use successfully for inground gardening just do not apply to containers and you will not have the degree of success with container gardening adhering to inground gardening practices as you would if you focused on the limitations of container gardening and addressed those limitations directly.

Dan - unlike white table sugar, raw sugar retains some of the molasses minerals and is not further refined by the bleaching process table sugar goes through. It uses uses phosphoric acid and calcium hydroxide to bleach.

Personally I don't use either but many of the soil food web research publications make a good case for the raw vs. refined. Of course they further argue that unrefined molasses is more beneficial than either.

Dave

Thank you gardengal, that is informative.

Again not disputing you, but I do prefer to use organic no matter what. As you said, tomatoes can grow anywhere- maybe not as well, but if I'm going to spend my time and money growing something I want to be successful, healthy, and plentiful you bet I'll give it the best I can give it. Correct me if I'm wrong, but soilless mix has less chances of chemicals and diseases I wouldn't want, and also don't need anything to aerate it. It hasn't so far in my experience. If the season ran long I probably would have problems. If I can grow on the ground I would though.