Garden Built on Sand

[Oxx]

I knew that when my house was built the builder spread sand on top of the soil before turfing it over. What I hadn't realised until today was that the sand goes down over a foot (30 cm). I don't know much about gardening, but surely this can't be a good thing. Water won't be retained. There's no nutritional value in sand, and any chemical fertiliser I apply will just wash away. So, what can I do to fix it? Apply some sort of top dressing regularly? If so, what is suitable and readily available in Thailand? There don't appear to be any worms (no worm casts on the lawn). Is that going to be a problem?

Thanks.

[Crossy]

How is the lawn holding up in the dry weather?

If it's doing ok then change nothing, you certainly don't want to go digging everything up

How far below the surface does the growing medium extend before you get to the sand?

What sort of grass do you have, broad leafed Malay or the narrow leafed Japanese?

Some interesting stuff on top-dressing here http://www.lawn-care-academy.com/top-dressing-lawns.html compost or good topsoil (or a mixture) is the stuff to use.

[Oxx]

I did say " I don't know much about gardening"! Anyway, I'll do my best.

The lawn just doesn't hold up in dry weather. I have to water it every day for over an hour to keep it green. (It's roughly 200 sq. metres.)

There is no growing medium. The top foot (at least) of "soil" is plain sand. (I stopped digging down at this point.) The reason I discovered this is because I now want to add some plants. Digging the holes I just encountered sand, pure sand.

No idea what sort of grass I have. Actually, it's a mix of at least four or five types. One is broad leaves, growing flat in rosettes. (To be honest, I'm not even sure if it is a grass or not. Lawn weedkiller kills it off, but it grows back.) Others range from "normal" grass to rather coarse, fast growing stuff.

(I had read that if you mow the lawn regularly - and I mow once a week - the coarse grasses and weeds would die out. Not happening for me. Would prefer not to use weedkillers.)

Thanks for the link. I wonder whether the bags of "soil" they sell, which appear to be mostly vegetable matter scraped from some forest floor, would be OK. The particles aren't that fine, though.

[xen]

There are two ways you can solve your problem with the sand -

• Build up the composition of your sand with the addition of fine clay particles or by the addition of organic matter such as compost. Do not add this in layers but mix it in as well as possible.
• OR
• The other alternative is to use plant material that will grow in sand or well drained soils - have a look at coastal vegetation for ideas. There are palms and casurinas ,that will do okay. Malay Grass will handle low fertility sandy soils quite well for turf . There are succulents for colour and plants like lavender (think Mediterranean style) that will adapt. Numerous other plants that will survive in sandy soils if you do a bit of research.

[petermik]

While on this subject and not wishing to hijack it can anyone tell me please where I can purchase some lawn weedkiller/feed

[Oxx]

While on this subject and not wishing to hijack it can anyone tell me please where I can purchase some lawn weedkiller/feed

I don't think you can buy lawn weed killer in Thailand. I bring a couple of bottles of Weedol with me whenever I return back to the UK.

Thai Watsadu sells bags of 16:16:16 pelleted fertiliser which does the job. (Other places like Homepro, Boonthavorn don't seem to carry it.) I think the brand's called "Rabbit". 3 kg bags. There's at least one other mix, but my (limited) understanding is that 16:16:16 is OK for grass.

Incidentally, I strongly suspect that Weedol kills Malay grass. (I now think the broad leaved invasive weed in my "lawn" is Malay grass thanks to previous posters. It definitely dies off after I apply Weedol.)

[dick dasterdly]

There are two ways you can solve your problem with the sand -

• Build up the composition of your sand with the addition of fine clay particles or by the addition of organic matter such as compost. Do not add this in layers but mix it in as well as possible.
• OR
• The other alternative is to use plant material that will grow in sand or well drained soils - have a look at coastal vegetation for ideas. There are palms and casurinas ,that will do okay. Malay Grass will handle low fertility sandy soils quite well for turf . There are succulents for colour and plants like lavender (think Mediterranean style) that will adapt. Numerous other plants that will survive in sandy soils if you do a bit of research.

Sorry to go off topic, but how does one obtain organic matter?

I wouldn't dare have a compost heap here as it would be breeding heaven for snakes?

Relying on the 'right' plants is problematical - as it depends on sun/shade etc.

Additionally, how does one find fine clay particles? Another genuine question as I'd love to add some clay to the soil to retain water.

I bought a lavender plant once (only time I've seen it sold here) and it quickly died. Not sure whether it was not enough/too much water or too much sun.

The only shrubs that survive well in v dry soils are frangipani and bougainvillea in my experience.

[overherebc]

When you mow the lawn do you remove all the cuttings or leave them to 'mulch' back in ? Leave the cut grass to rot back in.

Every couple of weeks or so buy a few bags of soil from your local garden centre and start spreading it then water it in.

Won't be an over night fix but it will improve over time.

[xen]

There are two ways you can solve your problem with the sand -

• Build up the composition of your sand with the addition of fine clay particles or by the addition of organic matter such as compost. Do not add this in layers but mix it in as well as possible.
• OR
• The other alternative is to use plant material that will grow in sand or well drained soils - have a look at coastal vegetation for ideas. There are palms and casurinas ,that will do okay. Malay Grass will handle low fertility sandy soils quite well for turf . There are succulents for colour and plants like lavender (think Mediterranean style) that will adapt. Numerous other plants that will survive in sandy soils if you do a bit of research.

Sorry to go off topic, but how does one obtain organic matter?

I wouldn't dare have a compost heap here as it would be breeding heaven for snakes?

Relying on the 'right' plants is problematical - as it depends on sun/shade etc.

Additionally, how does one find fine clay particles? Another genuine question as I'd love to add some clay to the soil to retain water.

I bought a lavender plant once (only time I've seen it sold here) and it quickly died. Not sure whether it was not enough/too much water or too much sun.

The only shrubs that survive well in v dry soils are frangipani and bougainvillea in my experience.

Looking for clay particles - if not available at a nursery which i doubt then find some clay and dilute in water and then apply the water infused clay to the sand. There is also a clay available for use in sealing dams and ponds called Bentonite (sorry i don't know the Thai word for it) that if used sparing could be used as an absorbent. Also Vermiculite or Perlite commonly used in Hydroculture could be used instead of clay .

Organic matter can be added by not only compost but by tilling in coconut fibre, grass clippings as somebody else suggested, green manure crops may be worth a trial, or any other "organic material one finds in the garden. It will take time and some effort but it will work.

There are many different forms of composting - i doubt if all of them would attract snakes . A Barrel compost tumbler bin may be one solution.

" Relying on the 'right' plants is problematical - as it depends on sun/shade etc."

That is why i suggested looking at coastal sites and the vegetation it will support ,particularly if the base growing medium is sand. One always has to consider sun /shade and other factors when planting out a garden.

[petermik]

While on this subject and not wishing to hijack it can anyone tell me please where I can purchase some lawn weedkiller/feed

I don't think you can buy lawn weed killer in Thailand. I bring a couple of bottles of Weedol with me whenever I return back to the UK.

Thai Watsadu sells bags of 16:16:16 pelleted fertiliser which does the job. (Other places like Homepro, Boonthavorn don't seem to carry it.) I think the brand's called "Rabbit". 3 kg bags. There's at least one other mix, but my (limited) understanding is that 16:16:16 is OK for grass.

Incidentally, I strongly suspect that Weedol kills Malay grass. (I now think the broad leaved invasive weed in my "lawn" is Malay grass thanks to previous posters. It definitely dies off after I apply Weedol.)

Thank you

[samuijimmy]

Removed a duplicate post

[drtreelove]

Xen, Overherebc and others have some good suggestions for gradual soil improvement. But you have inherited an ongoing challenge with this situation and I would offer a more extreme option.

If landscape plantings without the very limiting restrictions on what will grow in sand are important to you, I would dig out and remove the sand and replace with a loamy topsoil in the planting areas, and incorporate organic matter at the time of soil replacement. (Loam is a more balanced amount of clay, silt and sand sized soil particles, as opposed to the dominant sand texture you have described.)

Yes it's a big project and could be expensive, but if you have the budget, contractor and soil resources to do it all at once, it will take away some of the pain of gradual soil improvements over several years that have been suggested.

It's a good lesson for those who are building, buying or renting property. If the landscaping is important to you, get involved in the site preparation early on. Assess the soil before you acquire the property, and insist on quality topsoil in the areas that you anticipate landscaping, before you find out the hard way like the Oxx.

Good soil is the key to plant health, nutrient availability, resistance to pest and disease factors, and water efficiency . With sand as soil you will be spending more time and money on watering and fertilizing and constantly trying to upgrade the quality with imported materials.

[drtreelove]

Attached some general information on soil:

All about soil.pdf

[willyumiii]

If you can aerate the sandy soil ( poke deep hole in it) and then topdress with organic matter, it will solve your problem.

To aerate, use a spading fork and male holes about every 8 inches over the entire area.

Then top dress with organic matter and water it in well.

The best organic matter I have found in Thailand is shredded coconut husks. I buy it in 4 cu ft bags for about 80 baht a bag.

The problem with sandy soil is that it does not retain any water or fertilizer, but it is great for root growth if you can keep it moist.

P.S. I was a horticulturist and landscaper in my previous life and I am confident that my advice is good!

This is the tool I am referring to and they are available in Thailand.

[dick dasterdly]

When you mow the lawn do you remove all the cuttings or leave them to 'mulch' back in ? Leave the cut grass to rot back in.

Every couple of weeks or so buy a few bags of soil from your local garden centre and start spreading it then water it in.

Won't be an over night fix but it will improve over time.

Back in the UK it seemed obvious to leave the grass mowings to mulch back into the lawn, as my interest was in the flower beds - so the lawn had to make do with nothing more than being mown and the dandelions/bindweed etc. being gradually dug out (a never ending job).

Living here, I employ gardeners to come in every couple of weeks to mow the grass/cut back bougainvillea and bamboo/remove all the fallen leaves. You make a v good point, that I need to tell the gardener to leave the grass cuttings rather than taking them away .

I'm honestly not exaggerating - I've put hundreds of bags of soil in the flower beds over several years, and you're right insofar as the soil is slightly better - but only slightly....

There must be a way to compost the multitude of tree leaves as I expect they'd break down v quickly in this heat? But as mentioned before, I daren't build a compost bin as the snakes would love it as a breeding ground.

[dick dasterdly]

There are two ways you can solve your problem with the sand -

• Build up the composition of your sand with the addition of fine clay particles or by the addition of organic matter such as compost. Do not add this in layers but mix it in as well as possible.
• OR
• The other alternative is to use plant material that will grow in sand or well drained soils - have a look at coastal vegetation for ideas. There are palms and casurinas ,that will do okay. Malay Grass will handle low fertility sandy soils quite well for turf . There are succulents for colour and plants like lavender (think Mediterranean style) that will adapt. Numerous other plants that will survive in sandy soils if you do a bit of research.

Sorry to go off topic, but how does one obtain organic matter?

I wouldn't dare have a compost heap here as it would be breeding heaven for snakes?

Relying on the 'right' plants is problematical - as it depends on sun/shade etc.

Additionally, how does one find fine clay particles? Another genuine question as I'd love to add some clay to the soil to retain water.

I bought a lavender plant once (only time I've seen it sold here) and it quickly died. Not sure whether it was not enough/too much water or too much sun.

The only shrubs that survive well in v dry soils are frangipani and bougainvillea in my experience.

Looking for clay particles - if not available at a nursery which i doubt then find some clay and dilute in water and then apply the water infused clay to the sand. There is also a clay available for use in sealing dams and ponds called Bentonite (sorry i don't know the Thai word for it) that if used sparing could be used as an absorbent. Also Vermiculite or Perlite commonly used in Hydroculture could be used instead of clay .

Organic matter can be added by not only compost but by tilling in coconut fibre, grass clippings as somebody else suggested, green manure crops may be worth a trial, or any other "organic material one finds in the garden. It will take time and some effort but it will work.

There are many different forms of composting - i doubt if all of them would attract snakes . A Barrel compost tumbler bin may be one solution.

" Relying on the 'right' plants is problematical - as it depends on sun/shade etc."

That is why i suggested looking at coastal sites and the vegetation it will support ,particularly if the base growing medium is sand. One always has to consider sun /shade and other factors when planting out a garden.

I've never seen clay particles, vermiculite or perlite in the garden centres I've visited, probably because they buy their plants rather than growing their own?

Similarly, I haven't seen a barrel compost tumbler bin here - but I could ask on the Phuket forum where the compost bin, clay particles etc. are are sold here. I had a tumbler compost bin in the UK and the 'compost' was always v liquidic, but that was a v different climate - and it didn't matter as it was still a great fertiliser and the tiger worms (?) bred like mad!

Off topic - which reminds me of a horror story . I moved a new, plastic compost bin into a spare, unheated bedroom one winter - thinking that it would be too cold for the supplied worms out in the garden. The spare bedroom was obviously too hot for them, as one morning I discovered hundreds of worms were climbing/had climbed out of the bin and were all over the floor!

Back on topic, I live v close to the coast and few plants or shrubs thrive because the soil is so dry - partly due to the soil and also because the trees suck out any moisture.

There's a shrub with large, yellow flowers (sorry, no idea of its name) that flowers well despite the dry soil - but it takes a while to get established and flower- if its left to its own devices (i.e. not watered).

[xen]

There are two ways you can solve your problem with the sand -

• Build up the composition of your sand with the addition of fine clay particles or by the addition of organic matter such as compost. Do not add this in layers but mix it in as well as possible.
• OR
• The other alternative is to use plant material that will grow in sand or well drained soils - have a look at coastal vegetation for ideas. There are palms and casurinas ,that will do okay. Malay Grass will handle low fertility sandy soils quite well for turf . There are succulents for colour and plants like lavender (think Mediterranean style) that will adapt. Numerous other plants that will survive in sandy soils if you do a bit of research.

Sorry to go off topic, but how does one obtain organic matter?

I wouldn't dare have a compost heap here as it would be breeding heaven for snakes?

Relying on the 'right' plants is problematical - as it depends on sun/shade etc.

Additionally, how does one find fine clay particles? Another genuine question as I'd love to add some clay to the soil to retain water.

I bought a lavender plant once (only time I've seen it sold here) and it quickly died. Not sure whether it was not enough/too much water or too much sun.

The only shrubs that survive well in v dry soils are frangipani and bougainvillea in my experience.

Looking for clay particles - if not available at a nursery which i doubt then find some clay and dilute in water and then apply the water infused clay to the sand. There is also a clay available for use in sealing dams and ponds called Bentonite (sorry i don't know the Thai word for it) that if used sparing could be used as an absorbent. Also Vermiculite or Perlite commonly used in Hydroculture could be used instead of clay .

Organic matter can be added by not only compost but by tilling in coconut fibre, grass clippings as somebody else suggested, green manure crops may be worth a trial, or any other "organic material one finds in the garden. It will take time and some effort but it will work.

There are many different forms of composting - i doubt if all of them would attract snakes . A Barrel compost tumbler bin may be one solution.

" Relying on the 'right' plants is problematical - as it depends on sun/shade etc."

That is why i suggested looking at coastal sites and the vegetation it will support ,particularly if the base growing medium is sand. One always has to consider sun /shade and other factors when planting out a garden.

I've never seen clay particles, vermiculite or perlite in the garden centres I've visited, probably because they buy their plants rather than growing their own?

Similarly, I haven't seen a barrel compost tumbler bin here - but I could ask on the Phuket forum where the compost bin, clay particles etc. are are sold here. I had a tumbler compost bin in the UK and the 'compost' was always v liquidic, but that was a v different climate - and it didn't matter as it was still a great fertiliser and the tiger worms (?) bred like mad!

Off topic - which reminds me of a horror story . I moved a new, plastic compost bin into a spare, unheated bedroom one winter - thinking that it would be too cold for the supplied worms out in the garden. The spare bedroom was obviously too hot for them, as one morning I discovered hundreds of worms were climbing/had climbed out of the bin and were all over the floor!

Back on topic, I live v close to the coast and few plants or shrubs thrive because the soil is so dry - partly due to the soil and also because the trees suck out any moisture.

There's a shrub with large, yellow flowers (sorry, no idea of its name) that flowers well despite the dry soil - but it takes a while to get established and flower- if its left to its own devices (i.e. not watered).

I am certain i have seen small bags of vermiculite or perlite in Big C or was it Tesco in the garden section but buying it in small bags is only suitable cost wise for pots or using for propagating . Maybe the hydroponic section/forum may be useful for larger quanities.

I must admit i had to laugh about all the worms evacuating the bin . What a mess finding them all.

Being a handyman i would have built a tumbler compost bin out of one of those blue drums with a bar through the centre. Mount it off the ground so you can turn it .You could be as fancy as you like or keep it basic . A hinge and catch on a simple door and you have a tumble compost bin.

With the leaves i would be just using them as mulch. They will slowly break down plus help in keeping some moisture in the soil - how much depends on the situation/location. You can run the lawn mower over a pile of leaves to make them smaller and easier to mulch. In such a climate as Thailand i could never work out why mulch is not used more - apart from it appearing to be untidy to some.

Hope that is some help.

[xen]

Xen, Overherebc and others have some good suggestions for gradual soil improvement. But you have inherited an ongoing challenge with this situation and I would offer a more extreme option.

If landscape plantings without the very limiting restrictions on what will grow in sand are important to you, I would dig out and remove the sand and replace with a loamy topsoil in the planting areas, and incorporate organic matter at the time of soil replacement. (Loam is a more balanced amount of clay, silt and sand sized soil particles, as opposed to the dominant sand texture you have described.)

Yes it's a big project and could be expensive, but if you have the budget, contractor and soil resources to do it all at once, it will take away some of the pain of gradual soil improvements over several years that have been suggested.

It's a good lesson for those who are building, buying or renting property. If the landscaping is important to you, get involved in the site preparation early on. Assess the soil before you acquire the property, and insist on quality topsoil in the areas that you anticipate landscaping, before you find out the hard way like the Oxx.

Good soil is the key to plant health, nutrient availability, resistance to pest and disease factors, and water efficiency . With sand as soil you will be spending more time and money on watering and fertilizing and constantly trying to upgrade the quality with imported materials.

I take your point about it about what i suggested being an ongoing challenge but with sand soils it always will be until the ratio between OM and sand begins to show result and the sand eventually becomes a sandy loam and the soil chemistry adapts. I have always believed that most soils with both time and effort can be improved at less cost than using imported soils , especially imported soils if they are of dubious quality. Excavating around foundations , unless done by hand ,even on to a depth of 30 cm can be a problem as well . It would be interesting to know what the parent soil is .

But without any knowledge of the site and the budget it is difficult to say what would be the best approach i think. I also agree entirely with your last paragraph.

Cheers

[dick dasterdly]

xen - Possessing zero handyman skills, making my own compost tumbler bin as a non-starter , but asking the gardener to mow the stacks of dead leaves (and then putting them on the flower beds) is a brilliant idea! He nearly always has to drive away to dispose of most of the leaves, before coming back to get the rest - so I'm sure he won't be too unhappy with this idea.

There are a LOT of leaves, and they would just fly away if put straight on the flower beds and the 'layer' would be v high - but if they are shredded, it should work.

[overherebc]

While on this subject and not wishing to hijack it can anyone tell me please where I can purchase some lawn weedkiller/feed

All in Thai so you might need a translator. Our gardener used this on the lawn to keep the good grass and kill of the crab grass etc.

[dick dasterdly]

Last weekend I bought 20 sacks of soil, a few plants and a kilo of fertiliser - all to be delivered.

The lady arrived at my house with the order and also brought some "natural fertiliser, better than the chemical stuff that destroys the soil" - or words to this effect. Her English isn't great and embarrassingly, my Thai is pretty much non-existent .

I was busy doing something else at the time, but whilst she was explaining I took a quick look at the sack of 'fertiliser' that had a short section in English - and it said "Bio-Organic mix" - which worked for me. The next day I read the English text properly - and it contained clay particles - something I would have barely noticed if it wasn't for this thread!

It turns out that its not fertiliser - its clay-based soil, which is far better than the 'normal' bags of soil that I've been using .

The front of the small 'sack' is all in Thai, but I gather its called Poi Sian from the English bit on the back.

[cooked]

I am coming to this thread a bit late.

First of all, many of us would be jealous of your sandy soil, but not for making a lawn!

Organic material / grass clippings : OK in theory but in thic climate AND in sandy soil, this will have a useful lifetime of a few months at most.

You seem to be on the right path in buying clay based soil, but in my opinion you need about 5cm worked into the soil, which for 200m2 comes to about 10m2!

I suppose you have thought about a sprinkler system? Or destroying your lawn by importing a truck load of 'normal' soil and ploughing it in?

Good luck anyway, personally I let the cows graze on our green bit.

[dick dasterdly]

I am coming to this thread a bit late.

First of all, many of us would be jealous of your sandy soil, but not for making a lawn!

Organic material / grass clippings : OK in theory but in thic climate AND in sandy soil, this will have a useful lifetime of a few months at most.

You seem to be on the right path in buying clay based soil, but in my opinion you need about 5cm worked into the soil, which for 200m2 comes to about 10m2!

I suppose you have thought about a sprinkler system? Or destroying your lawn by importing a truck load of 'normal' soil and ploughing it in?

Good luck anyway, personally I let the cows graze on our green bit.

I think you're responding to my post rather than the OP?

If so, I agree - its going to take one hell of a lot of clay-based soil as I've already gone through 15 'sacks' in the small, recently planted areas.... I'm hoping that my gardener will be able to find a source for far bigger sacks, but failing that, I'll use large quantities on new plants and only gradually add it to the rest of the flower beds.

Fortunately for me, I have no interest in the 'lawn' - which is only now finally showing a few signs of life after the recent rain. Its been non-existent for a few months...

I keep thinking about sprinkler systems (for the flower beds, not the lawn) - but it doesn't seem feasible unfortunately.

Can't begin to tell you how much I envy your cows, as there's something v lovable about them!

[petermik]

While on this subject and not wishing to hijack it can anyone tell me please where I can purchase some lawn weedkiller/feed

All in Thai so you might need a translator. Our gardener used this on the lawn to keep the good grass and kill of the crab grass etc.

Any idea where this can be bought?

[dick dasterdly]

xen - Possessing zero handyman skills, making my own compost tumbler bin as a non-starter , but asking the gardener to mow the stacks of dead leaves (and then putting them on the flower beds) is a brilliant idea! He nearly always has to drive away to dispose of most of the leaves, before coming back to get the rest - so I'm sure he won't be too unhappy with this idea.

There are a LOT of leaves, and they would just fly away if put straight on the flower beds and the 'layer' would be v high - but if they are shredded, it should work.

Gardener said that running his lawnmower over the piles of leaves, wouldn't work . Not sure whether this is because of the language barrier, or because he thought it would result in the swept up leaves being thrown all over the place again.

[xen]

xen - Possessing zero handyman skills, making my own compost tumbler bin as a non-starter , but asking the gardener to mow the stacks of dead leaves (and then putting them on the flower beds) is a brilliant idea! He nearly always has to drive away to dispose of most of the leaves, before coming back to get the rest - so I'm sure he won't be too unhappy with this idea.

There are a LOT of leaves, and they would just fly away if put straight on the flower beds and the 'layer' would be v high - but if they are shredded, it should work.

Gardener said that running his lawnmower over the piles of leaves, wouldn't work . Not sure whether this is because of the language barrier, or because he thought it would result in the swept up leaves being thrown all over the place again.

It will work , i have done it plenty of times but if he is not using a catcher then the leaves will spread and he may have to rake them up - extra work.