In established perennial beds, I add amendments 2 ways. When I plant something new I add amendments to the planting hole. I also add mulch to the surface each year and let the nutrients and organic matter move down into the soil through weathering and the action of critters like bugs, worms, and microscopic soil critters. I only till areas with annual plants, such as my veggie garden.

I don't know if you are aware that peat isn't the best choice for addition of organic matter since while it does add organic matter, it doesn't have much in the way of nutrients, and if it ever dries out, it doesn't rewet easily. Chopped leaves (running over them with the lawn mower works well) can be added to the surface as mulch, compost can be added to planting holes or the surface, and even wood chips used as a mulch will break down and add nutrients to the soil. All of these have more nutrients than peat to my understanding.

Sometimes the simplest is the best: lay down layers of recycled brown cardboard between/around your established perennials and top it with bark mulch. Worms LOVE cardboard; they'll come, poop and improve your soil with the added advantage it's free (aside from the bark mulch). Since it's an established bed you can't go the lasagna method route but as a suggestion for future garden beds, do some research on lasagna gardening.

Definitely wouldn't take everything out. Established perennials will benefit from worm poop but won't necessarily appreciate being dug up and replanted.

It's important to give perennials a season or two...or three to recover from being disturbed. If gardening teaches anything, it's patience.

When do I add more peat and how?

==>>> is this a make work project????

you havent ID'd .. for us.. any reason you need to do this??

in my garden... if it aint broke... i dont fix it ... eh???

ken

ps: you could add 2 or 3 inches of COMPOST ... to the surface.. in spring.. after you ID the seedlings ... and in doing it in a systematic way ... you could cover the whole bed in one season ... perhaps covering the spots left bare for the seedlings .. in fall ... while seeds fall on springs compost ... you could also hand harvest seed ... COMPOST the whole in fall... and reapply your seed thereafter ..

pps: there is a world of difference between compost and mulch ... make sure you understand why i differentiate ...

I did this years ago in clayish soil. I bought a lot of big bags of peat and dug that in. Later I found that if I also added coarse sand the results were much better and the plants did better. So, whenever I added more organic amendment for a planting hole or to make another bed, for each bag of organic I would buy bags of play sand and worked both of those in ---half organic matter and half sand -- before planting.

As I increased the number and sizes of the planted areas I found out that you can buy a ton of sand from a local concrete supply company for the same price as a single bag of play sand making for a very economical addition. We would just drive the pick-up to Dolese and they would load up the back with a few tons.

When we had a new driveway put in up front we also wanted to go lawn-free so we used a sod cutter to remove the lawn and had a whole dump truck load of concrete grade sand delivered and spread it on top. You automatically dig this in whenever planting anything and we end up with soil that soaks up water very quickly and deeply, stays moist longer and weeds pull easily. The roots appreciate it because they can breathe, get excellent drainage and it entirely eliminated the cracks I used to get in dry summers with the original "heavy on the clay" soil that used to bake into a brick-like nightmare in summer that no amount of watering would help. The native plants and grasses I grow do great in it. If I was growing other kinds of plants, I'd add organic like I did in the original beds but as it is, thats not necessary for prairie plants.

In the back we killed off the bermuda with round-up and we had a dump truck of top soil and another truck load of sand delivered. I made three large mounded areas of top soil and sand which left paths around the mounded areas.

We covered the entire property in river rock as a finish.

You don't have to go to this extreme but its testament based on personal experience of how much the addition of sand improved my red-clayish soil here.

I just thought of one more thing to add. I've added enough sand that I no longer have mud. It used to be that after a rain I couldn't garden until the ground dried out some and I would carefully avoid walking on my planted areas. That is no longer the case at all. I can dig a hole easily right after heavy rain and the soil is nicely moist and workable -- same goes for when its walked on.

This post was edited by TexasRanger10 on Fri, Nov 14, 14 at 14:37

Thanks everyone! I get the part about adding compost to add nutrients but i was more wondering about the soil texture and structure and breaking up the clay so that it's doesn't hold to much water and for healthy roots. I was wondering how long the peat lasts and when or if it need to be replentished.

Peat cannot be used as a top dressing. It would need to be dug in and that would disturb your garden.
Compost is the best thing you could ever use. It will feed your soil every nutrient, help to loosen clay, help to bind sand, if your soil is a little too alkaline or acidic it will help balance it, will help your soil retain moisture, worms will be happy and they help keep your soil aerated and you can make it for FREE. Do you think I am a fan? lol.
You can also purchase compost bagged or by truckload. You could mix course sand with it and the worms will still do the work of incorporating it into the soil if you top dress as suggested.
P.S.- I also use stepping stones.

I don't get how feeding the soil loosens up the soil? When I put peat in it, the clay is soft and moist, not hard. So doesn't the peat eventually go away over time?

I never really noticed the previous additions of peat when digging, it just gets mixed in and helps add some plant matter, sort of like leaves and grass cuttings which seem to disappear after a while. Over time it all makes for an improvement, it doesn't go away. One thing is sure, you would be hard pressed to over do it on adding organic matter and I have added a lot over the years in various forms.

You could try adding a couple bags of coarse sand to just a small area, work it in by turning over shovelfuls a few times. You should see a difference in the texture right away, it mixes in and breaks up the clay. After a rain, try the squeeze test and compare it to the other soil, it will crumble rather than make a ball that sticks together. That is a big texture change.

Oklahoma has sandy soil in the nice farmland up north and they can grow anything. Here in central Oklahoma its heavy clay with very little sand so sand is a good amendment here. Its not a one size fits all situations however.

The stockyards here sell compost by the truckload. I bought a pickup load for $10 once a long time ago but it wasn't quite cooked, in fact it was still hot, I burned my legs digging it in and the flies were buzzing everywhere. You have to be careful.

Once I had Asplunde Tree Service dump a load of ground up tree cuttings in my driveway. It was gross and fermenting by the time I got it spread around but any organic you can add is good. The stuff smelled like rotten spinach by the time I reached the bottom of the pile. Sometimes cheap is also inconvenient.

Some people collect bagged leaves from other people's curbs and take them home and dig them in. There's all kinds of stories I've read.

Besides nutrients, compost has organic matter. Just feeding, like with 10 10 10 won't help your soil structure, but any organic matter, including compost, will help your soil structure. If you add it to the garden surface every year, it will get incorporated over time. Worms are your friends.

There's a lot of subtly misguided advice here.

Mixing even coarse sand with clay can in some cases cause more problems than it fixes. If you're taking this route, you need to ask what kinds of plants you're trying ot grow and what you expect the amendment to do. For certain types of clays, for example, adding gypsum is a better long term fix for their hydraulic characterstics.

You can certainly top dress with peat moss. It "works" for certain kinds of plants. But, again, you have to ask yourself why are you doing this and what do you expect it to accomplish.

david, I have had someone post this every time I describe what I did. All I can say is, it worked miracles in my own particular situation and the proof is in the results. All it took was comparing root growth and size of plants in soil that I had done this in and soil I hadn't added sand to, it was dramatic. As I indicated, its not a one size fits all but in my case of starting out with heavy clay soil or to be more accurate, what I would describe as red dirt that formed 'dirt clods' and which cracked and baked hard when dry and was a muddy mess when wet which was difficult to water deeply in summer and impossible to work in wet seasons. After years of endlessly adding organic amendments for years, it made all the difference. I've never regretted it.

It would probably be best to get local advice when it comes to soil since each region has its own particular situation or just test a small area as I suggested to see if it improves the soil.

The OP was asking about clay soil and adding more peat and roto-tilling it in again. I wouldn't roto-till again but digging in around plants to add amendments would be a good way of weeding out the roots etc he mentioned along with improving the soil. It sounds like some digging is in order anyway so why not add some amendments at the same time? A top dressing would be good but theres still those undesirables left in the soil to deal with.

This post was edited by TexasRanger10 on Sat, Nov 15, 14 at 15:38

The OP asked when he should add more amendment. The simple and best answer is, whenever you can. The second answer would be, when you think your soil texture is not the best it can be, or not a good as you hoped. If you are still finding that the soil gets pretty hard in dry spells, or drains poorly, or your plantings really aren't thriving, then you might want to add more stuff.

Then follow the advice above. I also tilled in lots of organics when I built my beds, but I find that there is room for more. I do add any organic matter I can get my hands on (if I am out of compost) -- even shredded newspaper -- whenever I plant, and try to stick a shovel in and toss in some whatever between the plants whenever I think of it. This in addition to spreading compost, chopped leaves, and wood mulch.

ranger - "in some cases" as I said, it is not a good idea.

IF it worked for you, great. It may work for other people and you should by all means share your success with it. I guess I was just reiterating your caveat that it didn't apply in all situations; for that I apologize for not reading your advice more closely. And furthermore, in some cases(!), your advice IS actually better than tilling in peat or another 100% organic additive. Yes, they all breakdown. Faster in very warm climates like Texas. More on their breakdown in a moment. But point being, I am in fact glad you have stated that this worked better than adding organics for you, because I can totally believe it did.

"The simple and best answer is, whenever you can." That's a very simple answer. So simple that sometimes it is wrong in fact. You can almost always have too much of a good thing. If you added so much organic material that it becomes a significant, say > 30% fraction of the soil mix, and if it does breakdown too fast you will be left with a quagmire that is lower than the surrounding soil. Also, you can have a situation where a fair amount of the nitrogen you add to the soil is wasted just helping the organic matter to decay.

So I guess my main point is there's no one size fits all for fixing soil. Even my own views have changed. 10 years ago I would have said gypsum was a scam, that it didn't do anything. Because that's what my observation was. Then I moved to an area with the type of clay that response to gypsum, or more specifically the the calcium ion. Because I've actually mainly applied calcinic lime. Now I would recommend it, but only to people with this type of clay. Basically the Ca++ displaces other ions like Na++, Mg++ and to some degree H+ obviously, this alters the way the clay particles clump on a microscopic level. Areas of my yard that used to be permanently muddy for days after rains now drain very quickly.

This post was edited by davidrt28 on Sat, Nov 15, 14 at 17:14

I have been dumping my entire compost heap over the cleared vegetable beds right now. I compost everything all summer, in 2 gigantic heaps. I turn it a couple of times and it is big enough to get hot...but even so, there will be bits of it not fully composted but it doesn't matter since by the end of winter, it will barely be visible on the surface. This is all about keeping a nice friable texture (I never tread on these beds, nor dig). The compost stops nutrients leaching out during our winter rains and also stops soil compaction (my soil is silty and will make surface pans) I sometimes leave the weeds and veggie remnants lying on the surface and throw the compost on the top of them. There is not a massive amount of nutrition in compost (for vegetables), so I topdress with a granular organic mix in spring. Easy.

Soil types vary so much from one location to the next its hard to agree or disagree with advice, even types and colors of clay vary. Then you have to consider the goal and what kinds of plants you are growing as well. I've often seen people get downright militant on this subject on various forums, in fact, I've been slathered and outright ridiculed more than once and told adding any sand at all was tantamount to creating concrete. In some places that is probably true but who am I to argue with the local natives when it comes to their particular soil? North Carolina-ers are strongly advised against adding sand but I imagine that doesn't mean the whole state, or maybe it does. Heck, I wouldn't know.

My planted area is significantly larger in scale than a 20ft x 12ft area. I have to incorporate matter in on a big scale and I also want to keep my soil on the lean side to avoid ending up with a 'jungle' and cost is a consideration too. If I was growing vegetables for example, I would do things completely different. I am also on a slight well draining slope and have no low spots to deal with thankfully. Actually I think I have just about tried every type of amendment you can add at one time or another. I know making my own compost would end up with an amount that would be a mere drop in an ocean in my situation and that alone would never work for me. Even a ton is a small amount of additive.

The info people offer on a forum like this should just be taken as suggestions, not rules. Local information-- especially when dealing with soil-- is always best.

For most people with a clay soil that bakes to bricks, adding sand only makes it worse. The reason is not the sand, but they just don't add near enough. For most people, they are not willing or able to, or maybe they just don't believe they could possible need that much sand to make it work. Sand is very heavy and a ton is not very much. Ranger just kept adding till it was enough. Calistoga Al

Calistoga, you are correct. The grade of sand also relates to what you've said though. I can't find a literature citation for this, but I'd bet the finer the particles of sand, the higher the proportion required. Until you reach the point that you might as well just put down a layer of several inches of the sand. Which is still how golf courses are made in certain areas. That is why the current commercial practice for permanent structural enhancement has become to use very large particle additives, like pumice, turface, permatill, or the Japanese product called Isolite. (Which was used years ago by Davisson Golf on the National Mall in DC, to manage pedestrian traffic over grass fields. Now no longer imported) Any admixture of those is safe, without worrying about making matters worse. (BUT...my current theory is that in certain rare situations, if misapplied, even those could make matters worse for another reason. I'll get to that one of these days haha. Suffice it to say, it's not common but could happen) I do think they are a good idea for what _I_ am trying to do; and will continue to use them in certain areas.

One thing that hasn't been mentioned is roto tilling brings up seeds that have lain long dormant to the surface where they germinate with gusto. It can also break up certain types roots into small sections, each section being able to grow new plants. It usually takes a few tilling sessions prudently followed with either manual or chemical weed eradication to clear the soil of undesirables. People who naturalize large areas such as a prairie or meadow restorations are advised against tilling for this reason. If tilled, its best to wait a season or two until the area is clear of weeds/grasses before planting.