Stone
Well-Known Member
It's difficult to flush out solid (and even those in solution) salts in a very open medium because the water does not stay in place long enough to dissolve them. Remember that in the wild they are subject to mild to intense rainfall for days at a time. That's why the best way to water is with a sprinkler system that runs at least a couple of hours every now and then. That seems to give the best growth response. Of course most of us can't do that so the next best thing is to flush with plain water with 2 or more times the volume of the pot at least 3 times with perhaps 15 minutes between each go. This is to bring accumulated salts back down to a benign concentration. I do this maybe once/month but in between that I feed at every second watering with about 1/4 to 1/2 strength (0.25 to 0.5 grams/litre) and and also use a small amount of IBDU - which is a slow release urea - for a constant background of N.
I don't think we can get the same results as the growth of wild plants by using the concentrations of NPK measured in those natural systems for some reason. Also important to keep in mind that anions are the first to be removed from the pot by water (usually along with Ca.)
They are mainly - sulphate, phosphate, nitrate and molybdate, (and boron too) so they must be continuously replaced somehow. S is very easily flushed. I use 1- 3mm gypsum, which lasts for months for that and with the added benefit of extra Ca.
I don't think we can get the same results as the growth of wild plants by using the concentrations of NPK measured in those natural systems for some reason. Also important to keep in mind that anions are the first to be removed from the pot by water (usually along with Ca.)
They are mainly - sulphate, phosphate, nitrate and molybdate, (and boron too) so they must be continuously replaced somehow. S is very easily flushed. I use 1- 3mm gypsum, which lasts for months for that and with the added benefit of extra Ca.