best pH for growing white clover?

[mitch landen]

This may sound unorthodox, but ... here goes: I'm trying to get some decent ground-cover plants to grow on an old family cemetery plot. It was in shade over a hundred years, then (after a hurricane blew over the ancient, huge oaks nearby) it's been in full sun 20 years. Nothing growing on it but lichen-like stuff and maybe moss. The soil is mostly just fine sand. I tested it -- barely a nutrient registered, and the pH was super acidic.
Over a couple of years, I've added some potting soil, fertilizers, lime. Planted some bulbs (daffodils, tulips, alliums) with some success. Clover, though -- which I'd really like to have there -- never seems to take. Is this a pH issue? I haven't rec'd back results of the soil sample from there that I sent in this year, but I have the feeling it'll still be low in pH.
Any suggestions/anecdotes/warnings?
I have lots of ajuga running rampant in my yard and could carry some to the plot, but ... would that be worth a try? It seems to stay low to the ground, so I don't think it would be a problem re: maintenance. I live 40 miles from the site and am not so young anymore, so doing major support work for the plot is not something I'd get into. Don't know of any other relatives who would or could help out.

Thx much for any ideas!

 

[flowerbug]

This may sound unorthodox, but ... here goes: I'm trying to get some decent ground-cover plants to grow on an old family cemetery plot. It was in shade over a hundred years, then (after a hurricane blew over the ancient, huge oaks nearby) it's been in full sun 20 years. Nothing growing on it but lichen-like stuff and maybe moss. The soil is mostly just fine sand. I tested it -- barely a nutrient registered, and the pH was super acidic.
Over a couple of years, I've added some potting soil, fertilizers, lime. Planted some bulbs (daffodils, tulips, alliums) with some success. Clover, though -- which I'd really like to have there -- never seems to take. Is this a pH issue? I haven't rec'd back results of the soil sample from there that I sent in this year, but I have the feeling it'll still be low in pH.
Any suggestions/anecdotes/warnings?
I have lots of ajuga running rampant in my yard and could carry some to the plot, but ... would that be worth a try? It seems to stay low to the ground, so I don't think it would be a problem re: maintenance. I live 40 miles from the site and am not so young anymore, so doing major support work for the plot is not something I'd get into. Don't know of any other relatives who would or could help out.

Thx much for any ideas!

as you've found out, fine sand doesn't hold much in the way of nutrients and along with that it usually also tends to not hold water either. in such a situation i always suggest adding some clay to the soil to help with holding both nutrients and moisture.

as for the clover, the adding of some lime only goes so far, to make a longer term change to the area you'd have to put down some grit too in addition to the finer powder that is often used. again added clay will also help hold the pH amendments too.

you should not need a huge amount of added clay to make a noticeable improvement, but since this is a volume measurement it really depends upon how much work you want to do and how deep you want to work it in. some will leach away through time into the surrounding area and also soak down further.

if you are going to amend an area like that adding some organic matter while you are at it is often useful too as that helps for nutrients and moisture.

once you get it amended scatter your clover seeds and water it well.

 

[mitch landen]

as you've found out, fine sand doesn't hold much in the way of nutrients and along with that it usually also tends to not hold water either. in such a situation i always suggest addeing some clay to the soil to help with holding both nutrients and moisture.

as for the clover, the adding of some lime only goes so far, to make a longer term change to the area you'd have to put down some grit too in addition to the finer powder that is often used. again added clay will also help hold the pH amendments too.

you should not need a huge amount of added clay to make a noticeable improvement, but since this is a volume measurement it really depends upon how much work you want to do and how deep you want to work it in. some will leach away through time into the surrounding area and also soak down further.

if you are going to amend an area like that adding some organic matter while you are at it is often useful too as that helps for nutrients and moisture.

once you get it amended scatter your clover seeds and water it well.

Hi, bug -- your input makes total sense to me. Living in an area where clay is hard and omnipresent, well, I'd've never considered it desirable anywhere, anyhow. Then again, the idea of excavating the hard clay from around here and lugging it to a place to be distributed, might not be in the cards. I may just go the adding organic route -- old leaves, pine straw, whatever I can easily scrape together. The plot itself hasn't had much of anything added to it in generations, so .... maybe something would be better'n nothing. Much obliged ....

 

[Dirtmechanic]

Sounds like lack of water may be a consideration just based on the plants you say do ok. Thats a tough one. Charcoal could help, or vermiculite, It wicks so it would need to be at least deep enough to avoid wind and weather.

 

[mitch landen]

Thx a heap -- yet another good idea. I can see I'll have to make a production out of it if there's to be any real improvement made -- mixing in the good stuff is gonna take some effort. Well, we do what we must do ....

 

[seedcorn]

Clover, alfalfa all want a pH around 7.0. Less than that, may not even come up-germ and die. Great news is that alfalfa is a good product for sand as tap root will go deep to find water and collect it’s own nitrogen. There are recorded cases of alfalfa in AZ sand (think dry and hot) that live for decades. In Midwest clay lucky to get 5-7 years out of a stand. The last great news for you, 1 ton of lime will raise pH on sand a full point. So IF your pH is 5.0, 2 tons will be more than enough. (I’d have to go back to my notes as it might be 1/2 per acre to raise pH 1 point). Your soil test results should tell you how much lime they call for. After 2 ton/acre, extra lime that year is a detriment. That is why a pH on heavier soils May take 2-3 years to bring pH back.

Quick tid bit. 1 acre of soil 6” deep weighs 2M pounds. Do the math as to how many tons of amendments you would have to add to meaningful change the soil profile.

 

[Ridgerunner]

Some of us tend to think small. How big is that cemetery plot? If one oak tree could shade it the size might be manageable. In an old family cemetery you may be limited in using heavy machinery. Just trying to think how much work might be involved in prepping it and maintaining it.

Sand is made up of bits of certain rock crystals. Compared to other soil particles hey are pretty big, big enough that water can run through it. Sands do not hold water. An important property is that they are inert, no electrical charge. The particles being inert and the great drainage means that most nutrients leech out of the soil.

Clay is made from a different type of rock. Those particles are tiny compared to sand so the pure clay won't drain very well. But they are electrically charged. They hold most nutrients so most don't leech out. This electrical charge is a huge difference between sand and clay.

What we call compost is rotted organic matter, plant or animal. This is the miracle addition to a garden soil. Compost provides nutrition, though it can leech out. You always need to add more. A huge benefit is tilth, the workability of the soil. It helps sand hold moisture, it helps clays drain better. The best growing soil is loam, which is a mixture of sand, clay and organic material.

There are other particles, loess, silt, and such. And different sands and clays have different properties. You are not looking for a rich garden soil, you just want something that will support a ground cover, maybe clover. You don't need to hit perfection, just get close enough.

Now an anecdote. When I moved down here to suburbia I put in raised beds to garden. They were filled with what they call garden soil, what a horrible name. It was 60% sand and 40% compost, but a lot of that "compost" was shredded bark that had not broken down yet. No clay at all. You are supposed to mix it with your topsoil to get a mix that will grow things. I did not do that.

I had a huge nutsedge problem, really thick on the ground. I'd dealt with nutsedge before and did not want to again, so I dug out the top 6" or so of the soil to get rid of most of the nutsedge and get it down to a manageable level. So that garden soil mix was what I had to grow in. I had it tested and the nutrient level was horrible, lik yours. The pH was very high too, the opposite of yours. So I mixed in sulfur and eventually got the pH below 6.5. Took a couple of years. I also got some pure clay from a place that sells pottery clay and dug that in. Volume wise or weight wise compared to the sand-compost mix it wasn't a lot but it brought the nutrient content way up, most of them to really high levels. Nitrogen still leeches out, I have to add that but it made a world of difference. And I still add a lot of compost to it every year. Keeping stuff from drying out is still a big challenge, it is still mostly sand.

Clover will fix nitrogen into the soil but only if a certain bacteria is present. That bacteria forms nodes on the roots. You can tell that the specific bacteria is there if you pull up a clover plant and it has knots on the roots. If those nodes are not there you might want to get a specific inoculant, one labeled for clover, and introduce it. I grow a lot of beans and got the special inoculant for beans. It seems to come back every year, at least so far.

Plants need a lot more nutrients than just nitrogen. I think you might benefit a lot by adding about an inch of clay or less to that area and tilling it in. I don't think it would take much. But that would not be my first step.

I'd call your county extension agent after that soils analysis comes back and talk to them about how to get what you want. I don't know how North Carolina works. In Arkansas and Louisiana I generally got routed to an expert, whether on gardens or chickens. Some are better than others but they are generally knowledgeable and should know your local conditions. They may suggest something other than clover. I think what you want is a low maintenance ground cover, clover may not be the best choice.

I appreciate the challenge of maintenance. Practically all my immediate family has moved away from where we were raised though I'm related to most of the people that live in that area. These are not family cemeteries but country cemeteries, but most of my family from the past several generations are buried in two country cemeteries. My wife told she will bury me in one of those, hopefully not real soon. My uncle used to maintain both of those but he's now buried in one of them. Every year my brother and I send a check to the guy that is now maintaining them, mainly mowing. That is a lot of work, you need something low maintenance.

Good luck.

 

[Dirtmechanic]

Thx a heap -- yet another good idea. I can see I'll have to make a production out of it if there's to be any real improvement made -- mixing in the good stuff is gonna take some effort. Well, we do what we must do ....

If you just layer it with hardwood chip mulch and walk away, next year will find it improved. Feed it a little sugar water like a molasses and the life will emerge (faster) as the bacteria start the food chain. Fungi in 3 to 6 months fungi will be rooty enough to start drawing water up from the deep. I get bagged hardwood chips at lowes for about a buck and a half per cubic foot. Cheap dollars a cubic yard relative to growing mediums. 2 cubic foot bags for about 3 dollars and some change basically. It acts like a windbreaker, slows moisture loss, saves the back from digging. The insects will dig in the compost for you if you can keep it moist enough for them, which really shows up in the thickness. It is recreating the forest floor basically. Once its going you can grass seed with a compost over the top or do whatever. Above ground. Never tell anybody you are digging in a graveyard. It sounds funny!

 

[heirloomgal]

@Ridgerunner
That is one of the best soil info pieces I've read in awhile. It explains some of the experiences I've had with my, originally, heavy clay soils. I've done a lot to add to it over the years, and I'm happy with the improved texture and results I've gotten with it for vegetables. Some areas of garden though, where I had lots of 'garden mix' soil brought in, will crack & harden in hot dry weather. I've always wondered what soil component causes that, the clay? Most of my garden doesn't have this, but that one truckload we brought in and spread about ten years ago still does that, though the texture is wonderful when moist.

 

[Ridgerunner]

Some areas of garden though, where I had lots of 'garden mix' soil brought in, will crack & harden in hot dry weather. I've always wondered what soil component causes that, the clay?

Yes, it could be clay. Clay absorbs water and swells up. Then when it dries it shrinks. That causes it to crack. Sand does not absorb water so it doesn't swell or shrink.

One of my good friends is a potter. She occasionally sells some at a farmer's market with a friend that makes her living selling pottery, but my fiend just does it mostly for fun. Anyway I've chatted with her some in this. Pottery is not sun-dried brick making but she understands the principles. She's the one that gave me the idea to buy clay at a clay pottery shop.

When they make pottery they mix a specific clay and a specific sand in very specific amounts. The color of the pottery comes from the specific minerals in the clay. I got a white clay which contains a lot of calcium. It came from a specific quarry in Alabama. When they make pottery (and kiln-dried bricks) the clay adds certain properties and the sand keeps it from cracking and shrinking as it is cooked and dried out. What makes pottery and kiln-dried brick so hard is that they melt the minerals in the clay and sand to essentially make glass. How hot the kiln needs to be depends on what minerals they want to melt. That's a simplified version of course, details of anything are more complicated.

Sundried brick is different and is closer to what happens in the garden. They still mix specific clays and specific sands in specific ratios but they don't cook it hot enough to melt minerals. The sand is in there to keep the shape when the clay dries and shrinks, What makes sundried brick so hard is the electrical charges on the clay particles. When you get the clay wet and mix it up those electrical connections get loosened. When they dry those set back up and the clay gets hard as a brick. That's why it's not a good idea to work in a clay garden when it is wet.

You may have heard of adding fiber when you are making brick, maybe straw or horsehair. That's only for sundried brick, if you get a kiln hot enough to melt minerals straw and horsehair doesn't stand a chance. Those sundried brick are great in compression but not very good in tension. They are kind of easy to break if you bend them. Having fiber in there to help with that tension makes them easier to work with.

Before I retired I was a structural engineer and had to know something about foundations. I had a few courses on the mechanical properties of soils. That's given me a different perspective than some people have.

I've seen different things crack. If compost gets wet and then dries out it can crack. I'm not sure what the swamp muck we have down here consists of, silt for sure but a lot of organic material. It cracks a lot when dried and can stink from the organic material when wet, especially when disturbed.

What causes the cracks is the material swells when it gets wet and shrinks when it dries whether that is clay or something else.