Need advice on how to improve very sandy soil.

Mushroom compost, leaf matter that breaks down.....and what others suggested.

So it's looking a bit worse than I thought it would, the crap top sandy layer is actually the good layer there aren't even any roots further down than this layer and it only goes down about 50cm till you hit the next layer, we used to have a rather large bush here before and the roots just stop as the soil turns into golden sand, looks like just pure sand with no organic material in. I'll do a ph test on it as I'm sure there must be way off with it due to the absence of any roots.


Just reread 40s post and I really appreciate the help man. I think setting down a plastic layer is going to be a must here, need to start getting a move on as we have bad weather for the next two weeks and I don't want all of that to flow back into the hole....

Just add something with super-high CEC like bentonite (they sell it cheap by the huge sack), and grow lots of stuff on it with tons of roots to add stable organic matter over time. Soil is something you build, not something that comes in an instant recipe.

That is some challenging soil R O. I’ve seen a few recommendations for soil depth and I concur with 40’s. Two feet should be adequate. This year I dug about 3 foot holes to the tune of about 50-60 gallons. Added about 20% compost, 10% EWC and 10% peat and 5% manure. Also granulated organic pellets when mixing in and as a top dress periodically. This was all in decomposed granite. A better starting soil than yours due to it being a long standing citrus fruit and avocado grove. In hindsight, I would have dug about 12 inches deep and to a diameter of 6 feet. Then 24 inch rebar mesh or chicken coop wire to lay that 6 foot diameter frame one half into the amended soil you dug out. Top fill with a nice organic super soil mix. So the frame is half above surrounding soil and the mix is over 50% new organic additional and rest mixed in native soil. This will give you around 300 gallons equivalent of soil which will grow 12-15 foot plants producing many lbs. Along with others suggestions like top dressing and things like nitrogen fixing Cover crops in off season, ACT’s, etc. you can get the soil really rocking in a few years.

Mine only partially amended seems just fine this year.

Start out with a soil test from your county extension office for ~$10. Sandy soil can work quite well with the right nutrients added. The highest terps I've ever gotten were from sandy soil mixed with perlite.

The soil test was very helpful as it showed which nutrients were deficient. When I saw it was Mg deficient I realized why landscape plants and tomatoes outside had such a tough time growing no matter how much NPK I added.

Make a shitload of your own homemade biochar. Don't believe all the hype. Any charcoal from wood works just fine. Grind it up into all different sizes from dust to quarter size nuggets. Cheapest way to inoculate it is with your own urine.
That and lots of compost, like equal amount compost to sand and 20 to 30 percent biochar.
You will end up with a high quality soil they will love.

Couldn't you use it the way people use clay pebbles, and just run a constant dripper line over it? Then all you need is a reservoir, bottle nutes and a hose with holes?

Great outdoors said:

Make a shitload of your own homemade biochar. Don't believe all the hype. Any charcoal from wood works just fine. Grind it up into all different sizes from dust to quarter size nuggets. Cheapest way to inoculate it is with your own urine.
That and lots of compost, like equal amount compost to sand and 20 to 30 percent biochar.
You will end up with a high quality soil they will love.

Click to expand...

I make my own biochar and mix it with horse manure and add worms, works great. Biochar holds lots of nutrients and saves you money especially outdoors. No need to even feed the plants the last 3-4 weeks.

Red October said:

Hi everyone, I live in an area where our soil quality is very poor, basically just a few steps up from beach sand quality. I'm not sure how to go about this best as a large part of my personal grow will be outdoors this coming season and it's basically my first time trying to do it properly outdoors.

The area I have available is about 6x16 feet that I need to recondition and I'm going to dig it out next Monday, I was thinking 3 feet deep. I've already started in one section and the soil is the same quality the whole way through, very little organic matter and very hydroscopic when dry. The section that I started in I just added in a whole bunch of potting soil about 50/50 ratio but I noticed that when it mixed with the sand it became alot more water retaining and almost clay like. The small plants I managed to get going at the end of the season where starting to get PM even though I wasn't watering them much and this is something I want to avoid going forward.

I don't need it to be a super soil but I need something I can use without causing me more problems in the long run and it's something I can keep working on to improve over time but the growing season is any a few months away and I know I should get started earlier than later on this.

Many thanks for any help, it's much appreciated.

Click to expand...

When sandy soil is properly fed it's some of the best to use. I'd follow mother nature's lead and plant N fixers and or companion plants .....I've the seasons it'll get better and better w macronutes slowly breaking down ...doing a bed is perfect!

Add compost. There is a lot of good information here. Compost the part called % organic matter on a soil test is what you want to raise. The specifics of what you are seeking to address may differ for sand compared to clay but advice is the same. You may find that buying amendments doesn't go very far compared to sourcing compost materials. I would not worry about home made compost. Stuff meaning everything or just about turns into compost by itself with or without watering and mixing. There isn't any homemade (quality) compost for sale likely because people making it use it in their gardens. Since the sand is lacking organic matter, add organic matter. One year I piled lawn clippings in a row and tilled the cut grass and weeds into the clay soil. For that season it turned the rock hard clay into rich friable soil. I recall someone saying they continually add compost to sandy soil. If the compost is gold relatively speaking and not an inexpensive or mined bulk material then you may practically try to use as much as you can. Leaf mold or straw and hay will make a different compost than earthworms in a pile of food scraps for example. One may be more of a fertilizer while the other is for tilth moisture drainage and nutrition etc. Another way to approach improving land for cultivation is by growing organic matter on it. Cover crops are nitrogen fixing plants that make excellent compost. Over time growing organic matter (this can mean simply letting the grass go to seed instead of having bare soil) and adding rock dust mineral powder or Sea-90 may be about the same as adding compost and kelp. Have a look at dank.frank's grow thread, lots of detailed soil recipe info there. With some exceptions I would try to stay away from buying dirt or dirt additives if that makes any sense. Some places have free compost, from for example yard waste bins that people set out each week. Depending on how you feel about manure it is a source of organic matter and nutrients, the only thing is one person may use organic hay for bedding and another feeds oats and glyphosate treated plants or uses wood shavings for bedding. With your own collected leaves or veggie compost you know there are no horse deworming medicines pesticides or herbicides. Bagged grow media is full of cannabis specific pathogens.

Dig and replace! I have this 2 part thread bookmarked, for when I get serious about soil. Cations and PH are a problem I am wrestling with on a few acres.

https://www.icmag.com/ic/showthread.php?t=241964

Apologies for not maintaining the thread properly, I should actually subscribe to my own threads so I can see when there has been a response.

Just want to say thank you to everyone, I landed up digging out almost 2 feet of soil and replaced it with potting mixture basically with some extra clay and added in alot of extra amendments, a bit worried it is going to be too hot but nothing I can do now. Put down a plastic liner on the edges to stop the roots and moles from getting into the grow area but left the bottom open as I still want it to drain naturally.

The wind can get really bad so I built it with a shade cloth over that I can remove so that I have easy access to the plants in front in pots and I can also pull it back on good days when the wind isn't bad. Anything above 25km/h and the plants start getting leaf whip.

Just mix in the Precursors for Silt.

AKA dead leaves, etc.

6 inches of leaves, topped with an inch of dirt.

As many layers as you have the energy to make.

Gravity & Mother nature will do the mixing.

My soil is like a desert. I've had to beef up the soil around 30 fruit trees & am starting on another 20. As much to feed the deer, turkeys, and birds as to make people food.

Red October said:

So it's looking a bit worse than I thought it would, the crap top sandy layer is actually the good layer there aren't even any roots further down than this layer and it only goes down about 50cm till you hit the next layer, we used to have a rather large bush here before and the roots just stop as the soil turns into golden sand, looks like just pure sand with no organic material in. I'll do a ph test on it as I'm sure there must be way off with it due to the absence of any roots.


Just reread 40s post and I really appreciate the help man. I think setting down a plastic layer is going to be a must here, need to start getting a move on as we have bad weather for the next two weeks and I don't want all of that to flow back into the hole....

Click to expand...

Holy Moses that is shitty soil you are dealing with there!!

But is it a problem that can't be fixed?.... nope on the contrary.

Anybody who previously mentioned organic matter, compost, aged wood chips etc. Is on the money. Compost compost compost then some more compost.

If you have access to water and organic matter you are going to be fine. Are there any forests in your area, oak trees, pine trees?

moses wellfleet said:

Holy Moses that is shitty soil you are dealing with there!!

But is it a problem that can't be fixed?.... nope on the contrary.

Anybody who previously mentioned organic matter, compost, aged wood chips etc. Is on the money. Compost compost compost then some more compost.

If you have access to water and organic matter you are going to be fine. Are there any forests in your area, oak trees, pine trees?

Click to expand...

I landed up getting 4 cubic meters of earth brought over, had to wheel barrow it in from the driveway, was not fun but the only way to get a large amount of soil in there quickly.

Red October said:

I landed up getting 4 cubic meters of earth brought over, had to wheel barrow it in from the driveway, was not fun but the only way to get a large amount of soil in there quickly.

Click to expand...

Okay a thick mulch layer is going to be your friend, introduce red wrigglers and night crawlers and you will be laughing mate. The mulching material need not cost you anything only time and effort!

You can do an internet search for ' permaculture building native soils'.

moses wellfleet said:

Okay a thick mulch layer is going to be your friend, introduce red wrigglers and night crawlers and you will be laughing mate. The mulching material need not cost you anything only time and effort!

You can do an internet search for ' permaculture building native soils'.

Click to expand...

man I really like that idea, I'm really impressed with the quality of the soil, had to dig up most of it again today because I'd been trampling on it while work on the structure and the soil even far down was nice and warm so I'm thinking it's got a good amount of activity going on and the worms would just make it better. I need to figure out what companion plants I need to get as they will go into the ground just underneath the ledge.

You need to treat the soil and make sure it's nutrient-rich. Try a zeolite soil amendment we use this one all the time.

The zeolite captures nutrients and prevents leaching through. It's amazing for repairing and keeping soil great.

Used as an amendment or in a mix.

Lots of studies coming out recommend adding crushed biochar to sandy soil for a long term fix.

I'm planning on adding more of those types of ammendments next, took too long to get everything together and ordered soil, seems to be good though.