Keeping them wet, wet, wet!
 

One funnny note, I bought a couple of catasetinae this year, they were just a couple of really small backbulbs, cheeky sods, only just sprouted, for the money I expected something that would bloom this year.
Anyway, they just sat there in the bark they were sent in looking less happy as time passed, so in the end I snapped and put them in wet moss, and they perked up instantly.
So, I put all my back bulbs in wet moss, and they are all doing well. I am so lazy, when I watered them, I didn't empty the saucers under the pots and now the roots are growing into the water!

What's that they say about keeping them dry again?

Ah, the mythos of Catasetum. Yes, they do need a rest and must be kept quite dry, with Cycnoches and Mormodes needing bone dry with high humidity. However, when in growth they are close to impossible to overwater and require large amounts of nutrients. For this to work active roots are a must, otherwise you will get rot. Often new plants have no active roots and do best kept dryish until the roots develope. When you see new growth fotos with advice to let the roots get to 3"/8cm before watering, these plants are in high humidity and dessication is not an issue. On a windowsill this may not reflect the environment and the plants require regular misting to get them going. Also, temperature is critical to good root and bulb developement. Too cool and the roots will hardly develope. Most Americans overheat their homes, while most Europeans under heat them. This creates very different conditions. Patience is key, as watering too soon is an issue for many and, lets face it, most plant-lovers simply love watering their babies. Potting medium play a role, as well. In sphagnum you can water quite heavily, as it dry quickly pulling O2 into the root ball. With bark, watering to the point of soggy will O2 starve the roots, which is why coarse bark is recommended. Add to this that some Catasetum have almost no rest, while others spend 6 months in a dry oven in nature, there is a wide range of 'correct' conditions. Hybrids will be somewhere between. If you are stating I would recommend C. pileatum hybrids, such as Ctsm. Orchidglade.

In Spain you can grow them outside for 6 months. I do it, here, in Germany.

The interesting thing is, that with several new shoots, the roots developed to about 3/4 of an inch, and then stalled. I left them, and after a while I packed wet moss rround them and watered regularly so as to keep the moss wet, and they started to grow at once.

Outside? Bit difficult as the sun is very hot and they burn easily if the sunlight gets much over 50%

My plants are all outside and we've had over 2 weeks of 100+ degree days. Catasetinae LOVE the heat.

---------- Post added at 12:09 PM ---------- Previous post was at 12:07 PM ----------

You're most likely sacrificing this year's roots. Keep an eye on them as I bet they stop growing to the length they should reach.

Its highly likely you'll have good growth this year and then the plants won't do well next year.

Yeah, I know they love heat, but three of them got a touch of sunburn.

Can you expand your remarks please? Only they aren't all that clear to me.

I agree about keeping them wet. I keep mine in about 1 inch (2.5cm) of water all summer, I also start watering as soon as new growth occurs. This has been watered since April, I stopped watering in January.

This is a Cycnodes Taiwan Gold - the leaves are about 18 inches long and 3 inches wide, it gets the same treatment year on year and I have seen no degradation of the plant.

So, let me get this straight please. As soon as you see a bud, you start watering, and more than that you leave it stitting in water from that moment on?

I should be a big clearer. Yes, I water as soon as I see growth, although start off with a trickle, as the growth gets bigger I up the volume. Roots continue to grow- they don't stop. By the time summer comes - beginning of June they sit in an inch of water until sometime in September.

I must admit, somme of mine get to sit in water as soon as there is a bud. Before even.

Steve raises some interesting points, and I really hope he will contribute some more. There is such a divergence between what we are doing, and conventional wisdom, that I really hope to get as much info as possible on the subject.

Out of curiosity, I would love to see the new roots on this after the growing season is finished. Or if the plant is in a clear pot, can you post root pics?

---------- Post added at 09:18 PM ---------- Previous post was at 09:15 PM ----------

Bil sent me a PM to clarify and I sent him a response. However, I figure I should post my response here to contribute to the overall conversation:

Catasetum roots tend to stop growing when they encounter moisture. That's why you need them to be 4 inches (at minimum!) before you start watering. In nature they send the roots out before the rainy season and then spend their energy on growing leaves and bulbs.

If the new roots encounter moisture, they stop growing and try to put out new leaves and bulbs. Your plant might be able to send one year's growth with the energy stored in old bulbs plus the little bit of moisture that the new, stunted roots can provide. These plants will likely even bloom for you. However, such plants often won't survive the dormancy and will die the following year.

This is why the best growers wait as long as possible before watering. You want to get an giant root system to grow a giant plant, which will put out flowers and have a successful dormancy.

Plants that put out new roots that die are a bit of a mystery to me too. I've got plants that do that and they usually die. Its very frustrating. However, there are a few things you can do help the new, small growth. Stabilize the plant so it can't move in the pot, even with the strongest breeze. A plant that wiggles will bump the root tips on the media, causing them to abort. Picking the plant up or unpotting them to see the new roots will do the same thing. Keep your plant in the same spot if possible. If not possible, try to minimize the amount of movement until the growth is large enough to see well formed leaves. At this stage the new growth is unlikely to abort because of a new position relative to the light. Even then, move the plant as little as possible.

These guys love high temps, lots of water (when the roots are long enough) and high humidity. They don't need direct sun, but Spain is pretty far north so the sun should not be too strong. A 50% shade cloth would work or hanging the plant under an oak tree during midday would work too.