S/H Watering/Fertilizing

[marcmaubert]

Originally Posted by Ray

An orchid in nature gets fed every time it rains, and analyses of that has shown it to be typically under 10-15 ppm (rarely up to 25) Total Dissolved Solids, not just nitrogen. Fresh, flowing (aerating) water is far more important.

For a plant to add about 500 grams of mass - maybe a month for corn, a couple of years for a cattleya, or a lifetime for a little pleurothallis - it must absorb and process about 100 liters of water, but only about 5 grams of fertilizer nutrients.

You should flood the pot (which I define as "fill the rapidly pot to the top, and let it drain") at every watering, and never just "top up" the reservoir. As the LECA dries, the minerals precipitate in the pores, and don't quickly redissolve when rewetted. Repeated soaking/drying cycles concentrates the mineral residues, and if you have only topped-up the reservoir, rather than flushing the medium, it accelerates the process.

I did water some plants daily for six months as an experiment, but usually only get them 2-3 times a week. I just let the water drain.

The name of the technique implies a lot of water; if water usage is a concern that takes a higher priority than the care of your orchids, you might want to consider a different technique.

Ok, I'll try to flood twice a week during the growing season instead of just once. I'm thinking on reusing all of the excess water on a small container garden I want to start on my roof, so it doesn't all go to waste.