To use or not to use water absorbing soil polymers

[pattyp]

Hi everyone. I found a big bag of water absorbing soil polymer beads under my bathroom sink and am wondering if it is wise to use them in my garden. I have been digging up sod, turning the soil, and adding compost in preparation for the plants this spring and thought this would be a good time to turn in the beads, as well.

Any opinions about the use of water absorbing soil polymers?

Thanks.

Patty

[plantsnobin]

I don't like the sound of polymers in the garden, but then I don't know what they are really made of. I know people use them in containers so they don't have to bother with the plants so much, but I just can't see it. Seems like in the garden on a large scale it would be better to use plain old mulch of an organic nature.

[canadamike]

I'd keep them for containers if I were you. They are a totally neutral polymer as far as I know, but of course they can't be organic. But in ther ground there are many other things taking care of water retention, not the case in containers.

They will be almost useless in the ground and could end up being the total opposite one day in pots. I'd keep them for that purpose...

[americangardener]

Mar 14, 2009 17:19:19 GMT -5 pattyp said:

Hi everyone. I found a big bag of water absorbing soil polymer beads under my bathroom sink and am wondering if it is wise to use them in my garden. I have been digging up sod, turning the soil, and adding compost in preparation for the plants this spring and thought this would be a good time to turn in the beads, as well.

Any opinions about the use of water absorbing soil polymers?

Thanks.

Patty

I don't know why i'd use those. I can't see using them in an inground garden. You didn't say what kind of soil you have, but i guess it doesn't matter. You do know there's water already in the ground don't ya? It's usually underneath the garden, since most people only think of a garden as the top couple inches. But beleive me there is water under there. The deeper the soil the moister it will be.

Actually this time of year my water table is above the ground. But as the time goes by in the summer time it gradually drops lower and lower. But that dosen't mean the ground 3 ft down is gonna be completely bone dry.

I usually never have to water my garden. But then i make my planting holes 4-5 ft deep too. And if you're thinking that's too much work it isn't. It takes me a whole 30 seconds to make a planting hole 4 ft deep. Then i just fill it with water retaining materials like rotted wood which is just like a sponge or just leaves or weeds. Then fill the top 2 ft or so with compost. The reason it works is cause it gives the plants an easy route to get their roots down deep where the wetter soil is. And in my experience, most plants can send down their roots 4-5 ft or more if you give them the chance.

Anyways.. i just couldn't see using the polymers.. i have no need for it. But i suppose if you just want to garden in the top couple inches.. it might come in handy for an extra week or two before the soil drys out.

Dave

[grunt]

Dave forgot to tell you he makes his planting holes by driving a steel bar into the ground, and wiggling it back and forth. It's very quick.
On the polymers, they could compound your problem if it ever gets really dry, as they seem to actively seek water, and can with hold it from at least smaller plants. At least that is what I have seen said about them.
Cheers

[johno]

Mar 14, 2009 19:58:24 GMT -5 americangardener said:

Actually this time of year my water table is above the ground. But as the time goes by in the summer time it gradually drops lower and lower. But that dosen't mean the ground 3 ft down is gonna be completely bone dry...

I usually never have to water my garden. But then i make my planting holes 4-5 ft deep too. And if you're thinking that's too much work it isn't. It takes me a whole 30 seconds to make a planting hole 4 ft deep...

Dave

First I'll cast another nay vote on those polymer beads. I'd only use them in containers.

But Dave, I have a comment and a question. The comment is, I wish it didn't get bone dry three feet down around here. I've worked on construction sites where I watched them dig a basement (in summer) and it was dusty powdery dry 9 feet deep. We get seriously dry here, dry enough that I've considered the polymer beads a time or two... And the question: how the heck do you make a planting hole 4' deep in 30 seconds? Dynamite?

Edit: Oh, steel bar... well, I'd have a steel bar wore down to a nub before I wiggled it 4' deep here. Back to the demolitions license...

[macmex]

Johno, I can second that about wearing down a steel bar. But when we lived in the Pine Barrens, in NJ, I used to dig out stumps from trees over 15 inches across, in about 2 hours. We had pure sand. It was terrible for gardening.

George

[cff]

I've been seeing a lot of ads for rainwater harvesting systems in the past year, like Johno we've been hit hard with summer droughts. It would be nice to have a river to irrigate from but nothing like that close by, so I've been looking at different drought systems. To provide one acre with the equivalent of one inch of rain water = 27,000 gallons of water.

I figure a system big enough would exceed my weekly gardening allowance so I'm always interested in new methods. Tell us a little more about digging 3' holes is a few seconds Dave

[americangardener]

Ok.. probably shouldn't of mentioned it. You all probably have dirt to garden in. I don't.

I garden in a solid clay block, one acre more or less in size and at least 12 ft deep as far as i know. (that's as deep as i've dug). I don't have dirt like i said. Modeling clay.. grey clay that they would make a model from for a prototype car or make pottery out of. No sand, no rocks, no nothing. Pure solid clay. So my techniques may not be neccessary for some of you who have subsoil.

It's quite simpe really. First of all i use irrigation ditches for my plants. Dosen't have to be more than an inch or so lower than ground level.. and i can make those simple enough by just walking on wet clay.. one foot in front of the other.. heal toe, heal toe. That's my irrigation and drainage. It collects all the water runoff from the flat parts of the ground and directs it down my planting holes. So that's why i don't have to water. I let mother nature do it for me. Even in the most severe droughts i may only water my garden once or twice in the entire year.

Ok.. like i said.. my methods may work differently for some of you. But, remember what i'm working with. Wet clay is soft.. i can take a stick of on inch diameter rebar and push it down with nothing more than my body weight down to a depth of 6 ft. I use 4-5 ft cause i still need to pull it back out and i need a handle on it to do so. My rebar is only 6 ft long btw.

Simply method.. push it down 4 ft deep.. remember i do this in my indented irrigation troughs!
Maybe ream it out a little if i can at that depth... then pull it up about 2 ft and make wider circular motions.. just like stirring a pot.. only at a slight angle. I can ream out a hole that's a good 3-4 inch diameter at the top. That's it.. that's my planting hole.. now i suppose i could take a hand trowel and cut away some of the top clay and make a wider hole.... but i don't.

I take all the weeds and grass clippings and leaves and sticks and whatever else i have laying around and fill the bottom couple feet with that. It dosen't take much a couple hands full or so. Then i put some compost on top of that.. cause as you all know wood sucks the nitrogen up when it composts. Then I fill it up to a planting depth where i can place my transplants with a topsoil compost mix. Place the plants in and fill around em with my soil mix. That's it.

Simple if you ask me. Then the wood and leaves down in the bottom keep the hole open for filling with water.. and wicks water up to the upper part of the hole where the plants roots can reach it. Bottom acts as a reservoir for excess rain, yet drains it too. Then the water sitting in the hole will slowly soak into the clay and make that usable for the plants roots. By keeping the clay wet and soft the plants can use it. And my plants actually love the clay if i can keep it wet. It's the rock hard stuff on the surface they can't penetrate with their roots.

Which is another reason i don't till. All that does is breaks up the clay into chunks exposed to the air and sun and makes it harden faster. Now i know some of you may complain about compacted soil.. but remember i don't have soil.. i have clay! Clay is gonna go back to being clay even if i break it into small pieces.. as soon as it gets a couple weeks of rain it will compact itself back to it's original form. So what's the sense in tilling it? Clay will stick to other clay.. and then i'm back to a solid chunk.

Hope that explains a bit about the hole. Takes me 30 seconds to do mine. Your results may vary. But even in normal dirt i can see driving at least a drainage hole thru the hardpan and keeping a route for the plants roots down to the moister soil as beneficial. You guys just may have to work harder at it.

And Yah Johno.. even down 12 ft deep the clay can dry out. But that's why i direct my rain water down the hole where it can soak into the clay around the plants roots. That clay will stay moist for months even if the rest of the ground has turned into a big rock.

Oh and remember all.. i do my planting in june when the water table is still high and the clay is still moist. I've tried using the rebar in sept and oct before and i can usually get it down 3-4 ft deep thru the clay.. just its alot harder then.

[ottawagardener]

AM: This is really interesting as I don't garden in clay but there's lots around and it helps to know how to handle real bonafide modelling clay.

Thanks.

[americangardener]

Yeah.. i probably shouldn't of even mentioned the moisture being deeper. Didn't mean to sidetrack your discussion of polymers Patty. But, i'm probably closer to container gardening than anyone else here. I just make my containers in the ground and out of clay. I could actually see where it might be of some use. Not that it'd buy me more than a couple of weeks without having to water. But, i could see where i make my raised beds for root crops out of clay blocks where i might.. and i say.. might be able to use some underneath the soil i put in them. I just don't seem to have a problem with the soil drying out when i make my raised beds out of clay blocks though. The clay actually retains moisture for quite a long time. I don't think the added benefit of retaining some moisture in the soil mix would be worth the effort and time it'd take to mix any in with it though.. but if you got it and it's not gonna cost ya anything maybe you could use it sparingly in some containers.

Course if you got clay soil like i do... i sure wouldn't recomend using it in this stuff. That'd be useless. It'd have to be in regular soil.

[cff]

Well I didn't mean to help hijack the thread but I just had to know how you were digging a 4' hole in seconds, here in the southern piedmont of North Carolina (after a week of rain) you might be able to push a piece of rebar down 8 to 12 inches, anymore than that and you would need a sledge hammer

[americangardener]

Yeah.. CFF..

My original point is still valid. The deeper you have your base for your garden the moister it wll get and stay moister longer. Sorry to hear you can't garden in the whole ground.

Up here in the North we have what they call seasons. Got the cold snowing season like now, Then the rainny wet season like in a couple months.. and then it gradually changes thru the hot humid season into the nippy season where ya need a light coat to get in the last of the harvest.

It's during the rainny wet season when our water table is to the surface. Which makes it convient since that's right before planting time. In June the water table is still just a few inches below ground level. Well at least if you garden in an old swamp it is. So i just make all my holes then. It's easier to make holes for the poles i use to tie my tomato plants up to when the clay is soft so i just put those in at the same time i make my planting holes. Sure they don't need the poles for another month, but it saves alot of work later on and they get firmed up into place by the time the plants actually put some weight against em. Once my clay hardens in the top ft or so it's like concrete. And by july it'll be hard!

Yeah.. i keep forgeting not everyone is as lucky as i am when it comes to gardening. I could still see the rebar working for ya though. Here's something i do if i want to make holes in my concrete. Get the hole started... maybe a foot or so down.. then fill it with water. Let it soak down for a day or two, and the soil will be much softer underneath. Still might only get it down 3-4 ft.. but hey it's easier than lifting 10 lb shovels full of clay.. and just try cutting thru that clay with a shovel when it's hard. The rebar is still the best way to go for me.

Now Patty.. i still think if you're using a garden that's in ground.. there should be no need for the polymers. As i said.. the deeper you make your planting holes.. however you do it. The longer the soil will stay moist. Deeper soil dosent' have the drying effect of the wind and the sun.. just the problem of water going down even deeper. So, if you have a fairly deep hole.. whatever water you put on the surface... will eventually make it down to the roots.

Dave

[cff]

Hey we have seasons too !

Summer and almost summer



Hayne, be careful, there still snow up here, Dave and I are getting tired of it, and kicking some butt in the land of ''summer and almost summer'' might help us aleviate our frustrations

And to everybody, I used Dave's trick last summer, it was a bigger piece of metal, I'll use rebar this spring, but it worked fast and easy.

I had my best crop ever. Mind you, we had lots of rain, but I also think it has to do with subsoil nutrients....

It is back on my to do list, that's sure..

And there are a few sub-saharian communities that are using a version of this trick to reverse desertification.. water get in the holes during the short rainy season, they plant on top of the holes and the roots go deeper where water is stored.

There is a bit more to it, as they chanel the flow of rainwater, but now after many years they have transformed desert into fertile land and can plant in the shadow of bushes etc...

[Hristo]

Mar 14, 2009 17:19:19 GMT -5 pattyp said:

Any opinions about the use of water absorbing soil polymers?

These polymers are heavily advertised here last 7-8 years. The truth - they are not cost-effective on large scales. Simple count:
On average (depends on brand) they can absorb/retain about 1:300-400, i.e. 1 kg. of polymer absorbs 300-400 litre water. Usually the recommended application rate is 4-12 kg. per acre (applied once per 7-10 years). As I see in USA 1 kg. costs about $10 when in 55lb bag (much more in smaller bags). This means $40-120 per acre. Lets say a person apply 12 kg/acre, these 12 kg. will absorb/retain at best 4800 l. (1270 gallons) water. This means about 1.2 l. water per 1 sq. m. At best these 1.2 l./sq.m. will give you no more that 1 extra day before you should irrigate. I think most (if not all) of you will agree that this is not cost-effective.

But these polymers are very good when transplanting bare root plants, especially woody plants (trees, shrubs...). Just dip the roots in hydrated polymer before planting, also put a bit of dry polymer in each planting hole. This significantly increase the "catch" rate.