When to repot with S/H

[Ranchnanny]

As some of you know I have quite a few of my orchids in S/H and most are doing well. My question is how long should the orchid be in the S/H before it is repotted? Now that the orchids are in the GH the clear pots are getting scummy with algae. I have had to repot a few as they were not growing and going downhill.

Thanks in advance for your comments...

Sheridan

[Zoi2]

I don't mind a bit of algae, but when the pot looks green--I clean the pot, leca, and trim roots. The plants seem to put out new growth after they're cleaned up.
Joann

[Ray]

If algae growth is affecting your plants, you probably need to do some preventive work, like a periodic drench with Physan or chlorine bleach.

For the most part, however, it's just an aesthetic issue.

My rule of thumb on repotting is "when the plant is outgrowing (a.k.a. "breaking") its pot", and then I just move it up with no additional action, filling in the void space with fresh medium. Exceptions are if the plant is not doing well, then I unpot completely - including medium - and inspect. More often than not, I find that the problem is caused by the fact that I didn't clean out the organic matter well enough before moving it in, or the death of old, non-s/h roots, and I haven't flushed sufficiently.

As with any type of orchid culture, there is a lot more than just pot and medium that affects your success. As odd as it may sound, do not underestimate the benefit of more frequent watering of established s/h plants.

[Ranchnanny]

Thanks JoAnn and Ray I think that will be on my to do list today checking all my s/h orchids.

Sheridan

[Pilot]

Originally Posted by Ray

If algae growth is affecting your plants, you probably need to do some preventive work, like a periodic drench with Physan or chlorine bleach.

For the most part, however, it's just an aesthetic issue.

My rule of thumb on repotting is "when the plant is outgrowing (a.k.a. "breaking") its pot", and then I just move it up with no additional action, filling in the void space with fresh medium. Exceptions are if the plant is not doing well, then I unpot completely - including medium - and inspect. More often than not, I find that the problem is caused by the fact that I didn't clean out the organic matter well enough before moving it in, or the death of old, non-s/h roots, and I haven't flushed sufficiently.

As with any type of orchid culture, there is a lot more than just pot and medium that affects your success. As odd as it may sound, do not underestimate the benefit of more frequent watering of established s/h plants.

Ray what strength of bleach would you use to flush out the algae?

[Ranchnanny]

Ray should I remove the orchid before drenching with bleach? I can't imagine leaving the chid in the pot....how much bleach should I use?

Sheridan

[Ray]

I used to use one ounce of bleach per gallon of water, and never saw any damage, but have heard folks recommend a thorough drench, then water with normal fertilizer solution about an hour layer.

I now use Physan (1 teaspoon/gal) mostly because it smells better, but it is a better overall disinfectant too.

[Ray]

Back to repotting for a moment - ALL brands of LECA, like other media components, will build up minerals with time, so that may affect your thinking about timing.

How rapidly they do so will be affected by the porosity of the pellet - both size and distribution within the particle - how thoroughly you flush the pots with each watering, and your growing conditions.

As there is nothing you can do about the medium once you've purchased it, it's the other two you can control.

If you flush heavily, you obviously do a better job of "cleaning" the medium than if you minimally water, but maintaining high humidity is not only good for your plants, it helps redeuce buildup as well.

Just like the wicking from pellet to pellet, the absorption and release of nutrient solution takes time. In a humid environment, the absorbed material remains a liquid throughout the pellet, so as it leaves, the concentration of minerals stays relatively uniform throughout, including as it is taken up by the plant,

In a dry environment however, the solution at the surface might evaporate at a faster rate than the solution can move from the interior of the pellet. As that happens, the solution at the surface gets more concentrated, which forces the interior concentration to increase, and with more and more evaporation, the solids drop out of solution and can clog the pores altogether.

[Ranchnanny]

Thanks Ray

Sheridan