Self-watering pots with leca

[orchidphile]

Has anyone else been using self-watering pots with leca? About a year ago, I gradually started switching all my plants to this method, and I couldn't be happier.

I use DIY pots with a regular flowerpot inside that sits snugly inside a deeper ceramic pot. I crisscross two microfiber wicks, cut from a microfiber mop head, across the bottom of the pot. The microfiber is very wicking and keeps the bottom of the pot very moist. The leca does the rest.

To prevent the top layer of leca from desiccating surface roots, I use a top layer of gravel, which is non-wicking and also slows evaporation, stabilizes wobbly plants, and makes it easier to hold stakes in place. (Got this trick on Youtube, and it works great.)

Every time I water, I fill both pots with plain water and let it soak for 15 minutes to soak out organic matter and fertilizer salts. Then I dump this and refill the reservoir with fertilizer water. This is not much work, because I only have to water once every 3-4 weeks.

I've been doing this with phalaenopsis, cattleyas, oncidiums, dendrobiums, zygos, miltoniopsis, and even vandas, and I have yet to lose a plant. Problems have been minimal--some fungus acquired during our hot, humid summers, but that's about it. (This also works with gesneriads and other houseplants.)

Hope this inspires someone else to give it a try.

[Roberta]

A related trick that a friend of mine uses, especially when traveling... a wide shoelace with one end in a "reservoir" and the other end in the pot. Works with either bark or sphagnum. (probably would work with LECA too)

[Orchidking]

hey orchidphile,
I use this method on my dendrobiums. Like you say it works great. They grow so slow sometimes that it is good to just forget about them for weeks on end without watering.

My microfiber cloths have gotten mouldy but hasn't had any negative effects.

I like the stones idea. I use some pumice similar to seramis as a top layer on mine to keep the top a bit more humid.

[Ray]

Yes, they're fine, and obviously work for you, but be aware that your setup doesn't provide a lot of flushing, so mineral and waste buildup can be an issue.

Be sure to remove the inner pot with the plant and give it a very thorough flushing periodically.

[orchidphile]

Ray, Since I soak the entire pot in pure water every time I water, drain this, and then add new fertilizer solution, I can't imagine there would be much buildup. In any case, I've noticed very little efflorescence on my leca. (Since I have a double pot system, it's easy to soak the entire pot. With the single pot system of traditional semihydro, this can't be done, but flushing presumably serves the same purpose?)

---------- Post added at 07:07 PM ---------- Previous post was at 07:02 PM ----------

Originally Posted by Orchidking

hey orchidphile,
I use this method on my dendrobiums. Like you say it works great. They grow so slow sometimes that it is good to just forget about them for weeks on end without watering.

My microfiber cloths have gotten mouldy but hasn't had any negative effects.

I like the stones idea. I use some pumice similar to seramis as a top layer on mine to keep the top a bit more humid.

OrchidKing, Pumice is great in the media if you want more moisture, but I would worry about it as a top layer because it wicks--the same as leca, and when it's dry, I"m afraid it would pull moisture out of surface roots. That's why ordinary pea gravel or horticultural grit is so great as a top layer--it doesn't wick. It's really the wicking and not the dryness that damages surface roots, imo.

[SouthPark]

Originally Posted by orchidphile

It's really the wicking and not the dryness that damages surface roots, imo.

How about placing a layer of scoria of some recommended thickness on the top?

[Ray]

Originally Posted by orchidphile

Ray, Since I soak the entire pot in pure water every time I water, drain this, and then add new fertilizer solution, I can't imagine there would be much buildup. In any case, I've noticed very little efflorescence on my leca. (Since I have a double pot system, it's easy to soak the entire pot. With the single pot system of traditional semihydro, this can't be done, but flushing presumably serves the same purpose?)

Soaking certainly can be done, but my experience says that flooding the pot and letting it drain at every watering works fine. Assuming your plants are where the drainage is not an issue, it's much simpler than a soak. The only real negative with a pure water soak followed by a nutrient refill is that the nutrients will be delayed in their travel upwards through wicking.

OrchidKing, Pumice is great in the media if you want more moisture, but I would worry about it as a top layer because it wicks--the same as leca, and when it's dry, I"m afraid it would pull moisture out of surface roots. That's why ordinary pea gravel or horticultural grit is so great as a top layer--it doesn't wick. It's really the wicking and not the dryness that damages surface roots, imo.

I'll give that a "yes, but...". Dry LECA can damage new root tips, but if your top layer isn't moist, your conditions really ought to be more humid anyway.

I am battling that now, as I have my plants in from the humid outdoors for the winter, rather than having nice greenhouse conditions.

[SouthPark]

Originally Posted by orchidphile

I crisscross two microfiber wicks, cut from a microfiber mop head, across the bottom of the pot.

Does this mean that you use two strips of micro-fiber cloths, and you arrange these two strips in the form of an 'X' pattern arrangement ---- and these two strips lie flat along the bottom of the pot?

Maybe a photo would clarify things. A photo (picture/diagram) can be worth a thousand words.

[orchidphile]

Hi, Southpark. I've never posted pictures on here before, so I hope you can access these attachments. One picture shows the two-strand microfiber yarn as it comes from the mop head. (you can also use microfiber cloth, but it's a pain to cut in strips) In the other picture, the two strands of yarn have been unraveled and crisscrossed across the bottom of the pot. You can customize this any way you want. For very small pots you might use only one strand of yarn and three or more for very big pots. If you want to keep a pot very moist, you could run wicks all the way up the sides of the pot and even across the top of the leca.

[orchidphile]

Southpark, I've never worked with scoria, but I understand it's volcanic in origin. I would be afraid that it might wick moisture away from the roots the same way leca and pumice do. In any case, pea gravel is a great, if very dusty, solution. It's dirt cheap, it's available at any hardware store, it looks great, and it's weight and density are actually an advantage when used only as a top layer.

---------- Post added at 05:33 PM ---------- Previous post was at 05:27 PM ----------

Ray, I don't want to argue with you, because you're the expert, and it was your invention of the semi- hydroponic method that really got me serious about growing orchids.

But I can think of a good reason why you might be wrong about flushing vs. soaking. Salts deposit on the leca, and don't always come off easily. For those using tap water, the minerals in that are even worse. If you've ever tried to remove mineral deposits from a shower door just by wiping, you know it doesn't work very well. But if you put wet paper towels soaked in vinegar on the deposits and let them soak, they come off. By the same token, if you soak your leca in a mildly acidic solution of plain water, the deposits would have time to dissolve back into solution, or at least that's my hypothesis. I don't always acidify my soaking solution, but I probably should.