Kratky method?

[noochka1]

Good morning,

I'm curious if anyone is using this method to grow Paphs. I have quite a few seedling plants so the concept is very attractive from a time-management perspective. I am thinking that placing leca-filled (possibly rock wool, too?) baskets in a tray with 1/8-1/4" of nutrient solution should be sufficient for wicking, but it's just theory. Can anyone offer any practical real-life experience? Pros? Cons? Stupid idea? Have I missed an existing thread?

Thanks,
Scott

 

[noochka1]

No one? Maybe a bad idea...?

 

[Ray]

I grow the majority of my slippers in semi-hydroponics, which differs from the Kratky method (and was originated decades before it) by having an internal, rather than external reservoir.

 

[noochka1]

Thanks for the response, Ray. Does the location of the reservoir location make any difference? In my head it accomplishes the same thing regardless of its location. But maybe I'm wrong.
I converted most of my plants to this method a few days ago and I'm noticing already that the plants that I put in baskets appear to be wicking more efficiently than those in air cone pots, even though I have them in leca only (no rock wool). I had assumed that the internal cone would accomplish the same thing as external holes or slats, but that doesn't appear to be the case. That's frustrating.

 

[Ray]

As far as I'm concerned, internal versus external reservoir is irrelevant.

I am somewhat stumped by the "baskets wicking better than a plastic pot" thing, though. Assuming the environment and the LECA used in both are the same, there are two, competing factors that control the apparent rate of wicking - height of the LECA column and evaporation.

• The shorter the LECA column, i.e., the less distance from reservoir to the top, the faster it will all be wetted.
• The slower the evaporation rate, the faster all the LECA will be wetted.

In a plastic pot with no perforations (other than the drainage holes that set the depth of the reservoir) there is a moisture gradient, from saturated at the bottom, getting less so towards the top, thanks to evaporation. In a very humid environment, where evaporation is slow, that gradient is very slight, with the top of the medium being quite moist. In an environment favoring faster evaporation, there comes a point in the column that the evaporation has outstripped the wicking ability of the LECA, so the top of the medium is dry.

I would think that a basket, having 100% of its surface above the reservoir available for evaporative water loss, the longer the time period necessary for the LECA to be fully wetted than would a plastic pot, even one with slots and an air-cone center.

 

[noochka1]

I think it's strange as well, but that's what I'm observing. Perhaps it's humidity? My grow space is now normally >75%, and sometimes much higher when my humidifier goes berzerk (96% yesterday until I caught it...). Windows are nearly always open, but I live in S. Florida...so there's that.... I am observing a bit less moisture on the surface of my larger (4") pots. It might just be that I'm working with very small plants for the most part and have them in 2-3" baskets, so wicking is very efficient. I dunno.... I'm trying not to have more than 1/4" of nutrient solution in the tray. I'm gonna try not to over-think it unless I start to see root problems in 30 days or so. I'm brand new to this method, so yikes.

 

[Ray]

@noochka1 If you just moved them into a new culture method, you may see a bit of a stall in growth, possibly accompanied by some root loss, but hang in there (and keep applying the Kelpak)!

As roots grow, they "tailor" themselves on a cellular level to function optimally in that environment, and once they have grown, they cannot change. Move them into a different environment, and they are now suboptimal for the new conditions, and may start to fail. How rapidly that happens depends upon how great the "before" and "after" conditions differ.

That's one reason it's always best to repot just as new roots are emerging from the base of the plant.

 

[noochka1]

Yikes. I have a few that are hanging on by 1 or 2 really lousy roots (they came that way). In the event of total root loss, is it time to ditch the plant or are there ways to coax the plant to grow some new ones? Maybe a layer of rock wool on the surface to keep the base of the plant moist? I heard somewhere recently that Paphs grow new roots better in dry conditions??? I'd never heard that before, but maybe it's true. Dunno.

I am using Kelpak, K-lite, and both of the beneficial bacterial supplements you recommend. Can I put Kelpak and the 2 bacterial supplements in the reservoir or is that overkill? Right now I'm just doing K-lite @ 25 PPM. When I need to flush that? No idea. It's only been a couple of days.

 

[Ray]

I don’t buy the business about paphs growing new roots better if grown dry. If you intend to keep them wetter going forward, that’s the conditions they should be in when they grow.

Add the Kelpak to your irrigation water for the next 2 or 3 times you water them, as that ought to get them going.

If you are flooding the containers at every watering, the 25 ppm N fertilizer solution will be fine without added flushing.

 

[noochka1]

Thanks, Ray. I'll give that a shot and report back.

 

[noochka1]

Hi all;

Here are some pics of the new mini setups. I'm keeping about 1/4" of nutrient solution in the bottom of the trays (and Kelpmax, per instructions). Most of the pots/baskets are filled with 100% leca, but there are a couple larger ones with rock wool as well. They all seem to be wicking perfectly now but now I'm concerned that they may be staying too wet! I'm not just used to seeing this much moisture around the base of my paphs! The top layer of leca is damp to the touch, but not soaking - it does, however, get significantly wetter farther down in the pot/basket. And since most of these are very small, that's not very far and it's freaking me out a little bit!

Any suggestions / pointers / newb stuff I'm doing wrong?

 

[Ray]

1) Moisture is not an issue unless air is restricted.

2) Roots that grew in a dry medium, will be "unhappy" with a wet medium. However, roots that grow into a moist medium will be fine.

 

[noochka1]

OK, so I'll pray for some new roots