so, here is something I spent most of the day doing...
I'll tell you what, simply, and why. then give details, so, if you aren't interested, or it would never apply to you, you won't waste much time reading it.
Why?
I have one SSH(see photo #1) that is either getting over watered or is getting nute burn. I'm not giving it more or less than the others, and no others look like it does.
I believe the cause is inadequate drainage. I 'engineered' my soil, using larger diameter stuff at the bottom, several handfuls of small gravel, then mixed two types soil for the upper layer. those types are; a compact, sandy, gritty one, and a loose, tiny gravel, 'dirt', with some type of seed hulls in it. it's really a nice mixture. it's 'firm', but still, kinda, 'loose', lol. it holds some moisture, but also, drains well.
however, I ran out of the looser type and some plants got a lot more of the heavier, denser, soil. those are retaining a lot more water, and not draining well; therefore, looking 'over watered' or 'nute burned'.
What did you do??
here's what I did...
first, I scooped all the driest soil from the surface into a cup. then, carefully excavated a 'well' all the way to the bottom of the pot, near the edge. it was about an inch/3-4cm in diameter. then, I cut a drinking straw, for a smaller pot, in half(for larger, deeper pots, I used a full sized drinking straw). (see photo #2) next, I made little cuts in the sides of the straw, but not all the way through, and inserted that into the well, the hole. then, I filled the hole with small pebbles, stones, and soil (non-moisture retaining type), to the top of the hole, but not covering the opening of the straw. Also, small stones were placed around the top of the straw, after filling the hole, to keep the straw vertical, prevent it from 'migrating' from watering or soil settling, and insure no debris will fall into it, clogging it up(see photo #3 & 4). the straw should remain clear all the way to the bottom, for as long as possible. eventually, it will fill with silt or whatever particles in the soil. it was rather tedious to do this to all the pots with that type of soil. I didn't do that to ones with great drainage/low moisture retention.
IT MUST BE DONE CAREFULLY, AWAY FROM WHERE ANY ROOTS ARE EXPECTED TO BE FOUND! (some roots may be hit anyway, don't worry, the benefits should outweigh any damage done. however, if you're hitting a lot of roots, a different location should be located. use a 'probe' before digging)
Why did you do that??
I used to do soil drilling, many years ago, lol, for several years. it was my job. understanding how the structure of soil works and, of course, how to 'drill' into it was necessary. I'm only going to explain how this thing I did works, not explain all about soil...so, don't worry! lol
we did this(placing a 'tube' down into soil, below the surface), on a much larger scale, to see how much water would/could, run off a slope or how much collected, say, in a ravine. by drilling a hole and inserting a long(30-50m+, PVC tube, which had lots of slots cut into the sides w/a hacksaw. then filling the remaining diameter of the hole with sand; course grain, or gravel, so no soil would clog the slots, and fill the tube. water passed through the 'filter' and filled the tube with water. we could then, at a later date, use an electric water sensor to measure how much water had drained to that spot, over a certain amount of time.
of course, in nature, there are few natural 'drains' and most water only seeps down to the water table, or to bedrock.
and, I'm not interested in measuring or collecting the water.
I'm only interested in 'draining' it, and potted plants usyally have that advantage, but some of mine don't.
What is the goal of doing that?
if incorrect or imperfect soil has been used, like in some of my pots. this technique should solve the problem without having to transplant using different, proper, soil, because water will naturally pursue the the course of least resistance. that course should be my 'well'. water will pass through the slots cut in the straw and drain out of the pot. some water will remain in the soil, of course, because its the 'wrong type', moisture retaining. because the 'well', and straw, go all the way to the bottom of the pot the 'over watering' problem and consequent nute burn should go away and not return!
also, because the 'well' is now full of warmer air, not cool, wet soil...it will dry the surrounding soil much faster, thereby drying the whole pot faster...and, oxygen, from the air, is provided, in much greater quantities, to the roots/soil around the well.
I'm hoping this solution will clear up accidental over watering/nute burn, caused by improper drainage and even, from just over loving them with too much water/nutes.
this technique should be good for any pot of soil, even properly potted ones, and I plan to do it to every pot, in all future grows, even though it takes a lot of time to do.
because of the excellent drainage properties and the extra oxygen supplied to the root system, this problem should not reoccur, unless the 'well' gets clogged, which is easy to remedy. just pull the straw up a little and poke a wire, or something thin, down there to clear it out.