Watering fired clay?

subnet_rx

I have just potted some of my plants in fired clay (some 100%, some 50/50 with bark) as per a few articles I've read here and other places. It drains well, really well. The problem I'm really having with it as a beginner is how to tell when to water again. With soil, you can really feel the moistness or even wetness after watering, but with this stuff, it really seems to me to be the same 10 minutes after watering as it is 24 hours after watering. I can easily tell the completely dry particles by the color, but as to whether it is moist or wet, I'm really having trouble with that. Can I just assume that since I'm using this, I should have to water every day? Or should I wait for the top particles to dry out before watering again?

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waltr

Ah...the learning of when to water. An idea that I use are:
Push a bamboo skewer or chop stick into the soil, remove to check. I find that it is fairly easy to tell if the skewer is damp or dry.

subnet_rx

Thanks, I'm going to try that. The weird thing is, I have a moisture meter and it just won't register it. It works in my potting mix, cactus mix, and even orchid mix which contains huge particles.

MelloBonsai

Sometimes it needs a deeper pot to register. Chopstick method works good as the other poster suggested.

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bisjoe

A typical garden moisture meter has a metal tip seperated from the rest of the metal rod by plastic. The amount of electrical conduction between them is what measures the moisture. If there is no contact between them it will not register.

That means that potting soil, bad for bonsai, will give good acuurate readings since the particles are so small and close together. With a good gritty bonsai soil like calcined clay, there will be no such contact because the particles are
larger, far apart with gaps in between them.

For me a finger is the best judge of moisture, but with a really good, fast draining mix you can water daily to be safe and not have to worry about over watering.

nip

I have my trees in the same mixture. In training pots though, not shallow bonsai pots. My top inch or so dries out very fast while the remaining stays soaked for a much greater time period. Im going to try and put something on the surface to try and balance this out. I see some people watering everytime the surface gets dry, but my trees would stay soaked if I did this. The frustrating part is some folks water tons of trees like every other day, dry or not, and they grow great. While I take much care in watering exactly when each tree needs it, yet they still grow weak. Figure that one out.

bisjoe

There's something else going on. With a really well draining soil mix, like the calcined clay, you can water 2-3 times a day if you want and not have to worry about root rot, but it's a waste of time & water. Perhaps you could look at the lighting situation and your fertilizer program.

Joanie

The fired clays (Turface, etc) do dry on the surface very quickly, and can still be wet underneath. Two other methods of knowing when to water are:

1. Stick your finger into the soil up to the second knuckle, you can feel the moisture.

2. Feel the weight of the pot before and after watering. It's easy to tell whether it is wet or dry. But in this case, dry may be too dry.

At least you won't hurt them if you water them every day. The water drains extremely well in this sort of soil.

Your moisture meter is unable to measure the conductivity between the soil particles because it is too well draining. They don't work in this situation.

Joanie

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nip

Yea i think its something other then watering. Maybe fertilizer burn but I dont really know what that looks like. It was only my maples. Turned brown at the edges. Larger leaves would just stay half green/brown. small leaves would shrivel off completely. And it wasnt even full summer heat yet. I thought they were all dead, but they have all leafed out again this year after a LONG dormancy. I hope they slept well. All the leaves look fine as of now. But they all look fine this time last year. I guess my pine trees are ok. Cant really tell if they are live or dead! They havent sprouted, but they are still green. Oh and none of these had the roots touched or branches trimmed. They are left alone to grow.