Chronic bud blast on cattleya?

[flowerpower]

I have a few large bifoliate cattleyas. I'm fairly inexperienced with cattleyas but I have a few large ones I have had for some time. I have grown them to a good size with 15 pseudobulbs or so and large root systems. They are in LECA and seramis (not semi-hydro). They are healthy but I do let them dry out between waterings to avoid root rot. They are the type of cattleya that blooms directly from the top of the pseudobulb with no sheath.

The issue I have is the pseudobulb matures and the buds appear. They grow a bit bigger and then turn black and dry up. This is constantly happening and if I could get it to stop my cattleyas would be blooming constantly because they're pretty big.

They get good light and regular fertiliser. Decent humidity. Could I be keeping them too dry while in bud? Too warm? I'm not sure what I'm doing wrong but the blast has happened around 10 times now. They have successfully bloomed but it is the exception to get the buds to survive. They grow inside my home.

[Roberta]

In summer, when temperatures are warmer and growth is rapid, it is possible that they aren't getting enough water. You should be watering based on the rate at which they dry out, not a fixed number of days between waterings. I'm watering my Catts in general about every other day, but they're mostly outside, with lots of breeze and more and more in baskets with large bark. They pretty much dry out within a few hours. So your conditions may be very different. Is it possible for you to grow them outside during the spring and summer? If you have the space, they'll love you for it.

[flowerpower]

I'm planning to purchase more cattleyas as despite this issue I very much like them. I plan to try some new ones in semi hydro as I've had success with smaller divisions. Its sibling is in bark and the most troublesome one is in LECA. When I bought them I was experimenting on seeing which one would do better - bark VS LECA. I prefer the LECA medium because it means the plant is not disturbed with the repotting process which I find can mess cattleyas up if attempted too often. If I think about it the LECA one does blast its buds more than the Orchiata bark one. I will try more water.

[Orchid Whisperer]

I grow mostly Catts. When I have had bud blast, it is often when a plant that seems otherwise big enough is not getting quite enough light. I saw that you said your plants get good light, but I am not sure what yours are getting.

Is it possible to increase your light a little more?

[flowerpower]

They get direct southern light, slightly south east but mostly southern. The general growth of the orchid is quite good. The light is enough to spike my vandas that hang in the window. But come to think of it when my vandas spiked they also bud blasted! One opened its blooms but they were "crispy" and short-lived, and the other vanda spike turned black and dessicated before it even grew.

Could I be roasting them too much? I didn't think of that because the oncidiums did not mind the conditions but I keep them very well watered.

[Orchid Whisperer]

My Cattleyas tolerate light, short of burning, in northeast Georgia, USA. Our summer high temperatures are routinely 90 F (32 C), rarely up to 108 F (42 C). Cattleyas outdoors in all of that.

They get some light filtration, not really through shade cloth, just some window screen.

What does leaf color look like? If it is routinely near chartreuse, the light level should be OK. Emerald to pine green, they may not be getting enough light.

[Merita]

I have cattleyas in baskets of coconut fibers, hanging from the trees, with a substrate of rock lava and bark and you have to be watering them a lot in the summer. Now they are going to bloom 4 of them for the first time I will cross my fingers because I have bifoliada too.

[estación seca]

I suspect your problem is not enough water. They need a lot of water when in bud. I try not to let Cattleyas in bud ever dry completely. In LECA you could probably water a lot more than you are without causing root rot. There is a lot of air inside the container. Vandas in bud also need very large amounts of water, even more than usual.

Another thought - a small pest called thrips (singular and plural) loves to eat buds. They are famous for destroying Vanda buds. Consider using a spray insecticide in an aerosol can only on the developing flower stalks.