Soil - not self-watering

[tam91]

I have been growing my tomatoes in containers (dang walnut trees!) and having pretty good success. But there's always room for improvement - and I know I haven't been going by standard "rules".

I use 18-gallon rubbermaid-style totes. I have been using 1/3 peat, 1/3 topsoil, and 1/3 composted horse manure. I don't want to go to the SWC, I'm happy enough to go out and water my "babies". I haven't had a problem with them drying out, and I have a drip system and timer I can use, so if I want to go away it isn't a problem.

I am getting tired of the weeds, and I have easy access to bulk mushroom compost. So this year, I was thinking I would replace the horse manure with the mushroom compost. So 1/3 peat, 1/3 topsoil, and 1/3 mushroom compost.

So... this seems to work, but I would think I don't have the best aeration.

I do not want to buy container soil-less mix, honestly, that's just too expensive.

Is there something I can add to my existing mix, to improve the aeration (without breaking the bank)?

Also, I have not re-used the soil for tomatoes before, I just dump it out into the garden. I'm wondering about re-using some of it, mixing in new stuff. And... if I add whatever is recommended for aeration, will that stuff be a problem if I empty out the containers into the garden in the future?

[Heritage]

A few years ago I had access to mushroom compost and planted up dahlia seedlings into 5 gallon nursery containers. They did great for the complete growing season and there was very little breakdown or loss of drainage ability in the mix for the 4 months they were growing. I fertilized about the same as for a quality potting mix.
You might experiment with a few pots of just pure mushroom compost, just add a slow release (complete) fertilizer. You are lucky to have a source for mushroom compost.

Otherwise, as an additive for aeration and water holding, I use agricultural grade coarse perlite because it is the cheapest per sq. ft (I can get it for about 1.25/cu. ft). Also, most places that sell soil amendments in bulk will have "nitrolized" wood chips" at about $30-$40/cu yd. (last I checked) and this is often used at an amendment in potting mixes.

-Steve

[ireilly]

Perlite will be the most cost-effective in promoting drainage. Ray likes bark fines that you can get at the big box stores, and I agree that those provide a good drainage as well without adding as much carbon as heartwood mulch. Finely chipped pine bark is close to this. Both this and perlite provide a lot of the voids that help the plant roots transpire. The wood products will slowly break down but the perlite will be there long after we are not. His SWC mix is made to give good drainage because of the nature of SWCs. If you find out that they dry out too fast just increase the [soil and peat] to [perlite and fines] ratio.

I agree, mushroom compost is hard to get anymore.

[sprtsguy76]

Perlite will help for sure but. In my opinion most of the ingredients (if not all) you are using for your mix is really water retentive and does not drain well. Have you considered bark fines (fir or pine that are 1/8" in size or smaller) as a part of you mix? The reason I use bark fines as a main ingredient in my mix is because bark fines keep their structure much longer than any compost and dont break down into water retentive mush . Bark fines can be very affordable if you can find them in bulk. I like to make my own mix of 5 parts fir bark fines 1 part peat and 1 part perlite (plus lime and nutrients) and it works great all season long. Its very user freindly and almost impossible to over water and it has great aeration. JMO and good luck.

Damon

[jessennessen]

I also grow in non SW containers but I am very much a novice, so I would like to learn from you experienced growers.

I understand the importance of drainage in SWC because there are is always access to water.

But in non SW containers I would think the drainage should be less exteme or the soil would dry out to fast. Am I wrong?

Also I would like the growing mix to actually contribute with nutrients as it break dawn during the season. It does just feel a bit artificial to supply is all with fertilizers. Any thoughts on that?

Jens

[tam91]

Interestingly, I haven't really had a problem with drainage. When it's hot in summer, I water every morning.
I just wondered if I'd get better production if I made the roots "happier" with some more aeration.

I'll look into bark fines - the place right down the road from me that sells the mushroom compost may have something.

[amideutch]

I used white peat, bark fines and perlite with pretty good results. I would stay away from topsoil if possible. Naturally your going to have to add ferts during the course of the growing season. Ami

[tam91]

Why avoid the topsoil?

[susanlynne48]

Hope y'all don't mind if I jump in here.

Top soil consists of very fine incredients. So fine, they tend to compact easily, and retain too much water. You want some aeration in the soil, and some water retention, too. But, you don't want a mix that is substantially heavy mud.

Mushroom compost and manure both combine to create a mix high in soluble salts, too.

I like to use Al's 5:1:1 mix of pine bark fines, sphagnum peat moss, and perlite. The hard part is finding pine bark fines. I found mine at a local plant products firm for $4 for a 3 cf bag. Often it is sold as "soil conditioner". I add a handful of lime to it as Al recommends, and for my tomatos, a handful of Espoma's Tomato Tone.

Susan

[tam91]

Not trying to be difficult here - I understand that topsoil etc. retains water. But... it works in the ground, right?
And I have to water every day - so it isn't retaining too much water for my plants.
So it seems to hold just about the right amount of water for me.

But - is there a benefit to more aeration?

[jessennessen]

Originally Posted by tam91

But... it works in the ground, right?

Originally Posted by tam91

And I have to water every day - so it isn't retaining too much water for my plants.
So it seems to hold just about the right amount of water for me.

That is exactly what I am thinking. But then again I have only grown tomatoes for one season so I still have a lot to learn. With all that bark fines it seems to me it is just like growing i Rockwool.

Jens

[ireilly]

Duplicate entry - wiped

[ireilly]

I think you see you already know the answer. If you've noticed you need to water too often, add stuff to hold water. If you notice you are waterlogged, add stuff to promote drainage, create aeration with a digging fork, etc.

The thing about container plants is that they almost always need more watering than in ground plant because of the nature of having soils around the root ball holding in moisture (not so much with purely sandy soils). So you are watering more, and a partial effect is to tend to solidify particles that have less organic matter mixed in, and another partial effect is to flush a lot of nutrients.

Of course you realize we are treating everyone's soil as though it is all the same, but your topsoil is not my topsoil and that changes the dynamic. We strive for reproducibility in our methods but from place to place there is variation, unless we both use the same shipped-in stuff without any local inputs.

Loams are the best of all worlds because the higher organic content promotes many of the things we need as gardeners, including microbes.

I agree that salt is not desirable and I did not know that mushroom compost has that. I had heard manure does though.

Myself, I just keep the compost pile chugging along with with all kinds of kitchen waste and leaves and tree trimmings and small branches cut up (can't afford a decent chipper just yet). Everything (except the starters) gets some compost and some of the red clay subsoil we have here mixed in with all the rest, and then I just adjust things if they seem too moist or too wet, and that changes over the summer, as the temps here can get pretty high midsummer.

Oh yes - aeration. Most of the gas and water vapor exchanges by the plants occur through the stomata, although some also passes through the epidermis. So it is in the best interest of the plant to have air reaching the roots as well as other parts of the plant, alternated by regular watering - up to the point the plant does not get enough opportunity to transpire. And plants types vary in how much of each they prefer. With tomatoes, they tend to be fast growers in the warmer temperatures so they like both aeration and regular watering. IMO.

I guess I feel you should do what seems best and adjust as you go along, like we all do. Your plants will tell you what they like. But don't be afraid to look at the hidden things like the root systems as you cycle through each year's garden so you can directly see the effect your methods are having on plant health. I though it was interesting that you can see nitrogen-fixing in progress on bean plants by gently digging up a root and observing the Rhizobial nodules. I like stuff like that.

And all that info came from here on TVille too! What a great resource.

Walter

[tam91]

Well mine seem reasonably happy - I'm gonna be brave, and substitute the mushroom compost for the manure I think, as I'm tired of the weeds.
But while the drainage seems fine, if I can get some bark fines or something to improve aeration I think I'll do that, as I suspect that might be better for the roots.

[amideutch]

Tam, the dynamics of soil in it's natural environment (the earth) and in a container are totally different. Where a container is subject to temperature fluctuations, soil can and does harden decreasing permability, aeration, and overall not a good environment for root growth. Also you don't know what kind of pathogens are in the soil, good or bad. Plus moving a container filled with dirt can be a bear.
As far as water retention in soilless aggregates, I have had no problems and even in 5 gal containers I usually water only once a day. One reason for adding Perlite to your aggregate mix is water retention and aeration.
Plus during the course of the season you will have to add additional ferts as the plants mature. Ami