Watering Brassia Roquebrune "spider"

[Piao Liang]

I need help to take care of my Brassia. This is the first time I own one. I bought it at a specialized store (Orchidees Vacherot). I would like to know how to water it. I read that you have to water it more often than Phals. It is in bark medium. At the moment I am watering my Phals once a week, so my question is, how often should I water this Brassia? I have heard conflicting reports about the amount of light it needs to flower. Some say a lot, Cattleya kind of light and some say Phal kind of light. Many thanks for your help!

[estación seca]

You want the bark to be completely wet when you water, and then you want to let it dry until the water is almost gone. You must water when the plant needs it, and not by the calendar. If you go by the calendar, you may water too much when it is cooler and not enough when it is warmer.

One way to check medium moisture is to use a small, thin piece of wood inserted into the medium. Look at this thread:

Using skewers to determine when to water

Another way is to water the plant, then hold it and see how heavy it is. Each day pick it up and notice the change in weight. When the plant is almost dry, water again.

Europe is much farther north than the US, so people growing in natural light in Europe usually put their plants closer to windows than people in the US. Bright shade where I live is brighter than full sun in some parts of Europe. Maybe some people from Europe will answer you about light requirements for this orchid. Most orchids can tolerate plenty of light, but not so much that the leaves start turning yellow or burning. I would give this plant more light than a Phalaenopsis. I would keep moving it into more light until the leaves became very light green, almost yellow. I don't think it needs as much as Cattleyas, though.

It is also important to be sure the bark is not too old. If it is very dark and crumbles into small pieces, it will stay too wet and the roots might rot. Many people repot all new plants immediately so they can be sure the medium is good. Your plant has grown to the edge of the pot, so it needs to be repotted. I would wait until it finishes blooming and then move to a larger container when it starts growing again. It will grow a new shoot from the base of the largest pseudobulb. This may happen this summer or it may not happen until next spring.

You can read about repotting here:
http://www.orchidboard.com/community...and-repotting/

How I would do it: Select a container 3-5cm larger in diameter than this one. Bark breaks down over 2-3 years and must be replaced, and the plant will grow to the other side of a somewhat larger container in this time.

If you grow in bark, look for large chunks, like what is in the container now. Soak the new bark overnight in water mixed with a kelp extract to promote rooting.

Remove all the old bark from the plant. Place the smaller pseudobulbs against one edge of the container, with the newer growth pointing towards the center of the new container. Set bark around the root system. You might need to put a stake in the pot to hold the plant upright until it is firmly rooted. I would water this plant right away when repotted.

You will also need to fertilize the plant, because there are almost no nutrients in bark. There is a lot of information about fertilizing throughout this site, but many people do well with a general orchid fertilizer at low concentrations throughout the growing season, or a standard house plant fertilizer at 1/4 the concentration recommended for house plants.

[MrHappyRotter]

estación seca has it covered, but I'll throw in my two cents.

The watering question is always a little tricky, because there are a lot of variables you have to account for. You may very well have to water your Brassia more often than your Phals. In proper light and air movement, and in a loose airy mix or mounted, your Brassia is going to dry out quickly after watering. When they're happy and growing, they need lots of water and will handle being constantly moist. But I'd cut back on watering a bit in the winter, especially if the plants are getting less light.

Light is an easier issue. I've not yet encountered a Brassia that will bloom when grown in low light (i.e. Phal light), though I confess, it's not like I've grown that many species Brassia and I haven't exactly tried growing them long term in low light. Many Brassias do have an upper limit on how much light they can handle. I find that the smaller species sometimes produce stunted growths, and it seems to correlate with receiving too much light. Grown in slightly shadier conditions, subsequent growths will be fine. So, I aim to give Brassias bright shade / semi-shade. This is the same amount of light I provide many of my Phragmipediums, as well as my Miltonias, and for instance, my Dend Phal NOID.

[Piao Liang]

Thank you very much for your answers! The water is always tricky as I cannot judge by the roots as I can with Phals. Why are Oncidiums, Brassias etc always in a dark pot? I will do the skewer method. Thanks again!!