Catasetum Watering Consensus
 

First post, long time reader... Was looking for a while for some information on the topic of "how much water" and how frequently to water - and I found a lot of info... I even asked Fred Clarke and got his advice, but I think - as with everyone - my growing conditions are different, and I'm just not feeling like what I'm hearing seems to line up with what the plants are telling me.

Most questions revolve around when to water, when to fertilize and when to stop either of those things (or if you should ever completely stop). My question is how much should I be watering at this point. My plants are growing well (two Fdk. After Dark 'SVO Black Pearl', one Cycnodes Wine Delight, one Clowesia Jumbo Grace 'Alba'), but I feel like I should be fertilizing them more / watering them more based on what I read.

My growing conditions are that I grow completely indoors in a fairly large wardian case I built to control all aspects of their growing (temperature, light, air circulation, and humidity). I can set daytime temperature to whatever I want, nighttime drops to the high 60s (it's in my basement), there are good strong led grow lights that I can dim, as needed, and the humidity control is simply a matter of venting the enclosure with fans. My conditions are exactly this (right now): 86 day / 68 night, humidity a fairly constant 75%, and the light each plant gets varies by how close it is to the lights (which I have pretty much dialed in at this point).

Ok, now that all the background out of the way, so the question is this:
I've read some water / fertilize multiple times a week, I've seen some guidance where the plants should dry out slightly between watering (heard this from Fred Clarke too), but at the rate my plants are "drying out", I'd only water once a week tops. How often should I really be watering?

I'm betting if the plants were outdoors they'd dry a lot faster, but I'm not setup for growing outside (no trees / no shade / high winds most days which would toss plants around). When I held off watering till they dried on the top slightly, they did ok, but they seemed to be growing faster when I just watered every three days instead of waiting 5 or more to get them to dry a bit more.

On a related note, my Cloweisa is growing, but still seems to barely be drinking -do they start off or move slower? To be fair I just started watering it and it's not as far along as the Fdks or the Cycnodes.

First, welcome to active participation!
It is worth taking a look at the objective that you're seeking, and then work backwards to the "how to achieve". Most orchids grow really slowly, so don't need much fertilizer - they're not making much new tissue. Catasetinae in their rapid growth phase (like now) are bulking up with lots of new tissue - leaves, new pseudobulbs, roots - extremely rapidly. So they need much more of everything - water, minerals, light. I use some time-release fertilizer to supplement what I give in liquid form, but that's because I don't fertilizer my collection all that often. In the late summer, when they have pretty much reached full size, fertilizer can be cut back a bit. Once leaves start to yellow in the fall indicating the approach of dormancy, fertilizer is reduced some more and eventually stopped. Water is reduced. When they drop leaves, stop. If they don't go dormant by late December or so, stop watering anyway to force the issue. Now, the exact timing will vary based on genus, and for hybrids based on the makup. Some are just now getting to the growth time - and may be late to go dormant as well. For me, Clowesias tend to get into gear first, then Catasetums, then Cycnoches, then Mormodes. (combinations fall somewhere in between... I just watch them and respond to what they seem to want) But that depends on the specific plant, too... just observe and respond as seems reasonable.

Great, thanks for the reply. I like to think I'm managing pretty well so far with them. I got the rules down, or at least I have them in mind. With your watering, in early summer, do you let them dry out at all? Or just keep then evenly moist and then soak them every few days?

I can experiment, but in my (limited and first season) experience with these guys, the "dryest" I let them get while in active growth is where the top feels just barely moist... For reference, my 'SVO Black Pearl' is just about 24" tall from the bottom of the pot to tallest leaf right now in a 3" pot. For reference, I've attached a photo from almost two weeks ago at this point and I only started watering this plant (slowly at first) sometime early / mid may, when it reached about 8-10" in height.

You can even sit them in a shallow pan with water. When they're in rapid growth, Fred Clarke says "Water like monsoon" since that is what they get in nature at the "growing" time of year. So it's pretty hard to overwater them when they're growing so fast. They should never dry out. (They come from an extremely seasonal climate - very heavy rain in spring and summer, none at all in winter) In fact, it's amazing to me that the pseudobulbs typcally don't shrivel, or at least not much, being without water for several months. But since they have no leaves at that point, there is little surface to transpire water. They're superbly adapted to their environmental extremes.

Mine don't dry out from the time they get watered for the first time after dormancy ends until around November when they start dropping leaves.

I grow them a little differently but according to the general rules….

Mine are outside and they get wet if it rains. Any time of year. They are covered but only by an eave and they still get wet. I don’t have real dormancy for a lot of these. I had several start this year’s growth with last years still having leaves.

I keep all of mine in trays that hold water and use mostly inorganic media so there is always water available

I have 15-20 of these and I am NO expert but they are a LOT of fun. The conventional wisdom is correct but they can behave a little differently in a humid and wet environment

Yep, the hard dormancy treatment isn't as critical (or even needed a lot of the time) for tropical areas. Makes me miss Hawaii! lol

Hey, thanks for all the replies. It's been about a week and I've rapidly increased watering from every 3-4 days to heavy watering every two days - the time it currently takes to see no water (drops / drips) sitting in the bottom of the pot - since I have them in clear pots, I can check that. In the short time since I've been doing that, I'm seeing the p-bulbs fatten up significantly and ironically, instead of the roots "slowing down" and not growing, I see the plants pushing root tips what seems to be even faster. The largest plant is still pushing new leaves and is already a full 24" from base of the pot to the top of the plant, I'd expect this guy to top out at something close to 26" at least at this rate before the leaves are done growing - I had no idea this variety got that big.

My only hope is that I wasn't short changing the plants development potential by keeping watering to every 3-4 days - I think I may have been, but I'm hopeful they'll catch up. They never dried out so there's that, but they sure seem to have bulked up fast in the past two weeks. Can't wait to see these things bloom, hoping for two spikes on the biggest one, but may be a bit two early for that kind of display with a plant of only 4 bulbs total (2 of them new growths, one of them a bit on the smaller side).

Glad it's working - when in active growth, this group of orchids is hungry and thirsty - and growing so fast that you can almost watch them get bigger.

In the tropics here ----- my currently flowering Fdk plant is grown in 100% scoria (10 to 15 mm average diameter)- grown in full (can get quite intense) sun, and it just gets weak fertiliser at the beginning of each month, and some weak mag-cal at the middle of each month.

And I just use a water hose ------ and dump the water into the scoria every morning.

The pot sits on a drainage grate --- just in case ----- just so that the pot never sits in water. I just use a drainage grate.

It can get quite windy sometimes ---- the big scoria pot it's in is heavy and relatively wide, and fairly low centre of gravity ------ pretty much no chance of it toppling over ----- unless there was a big cyclone or tornado heheh.

To really lift those chances for flower spike production ------ give the Fdk type plants as much sun as possible.

As for fertiliser ------ it is probably true that there the more fertiliser (up to a point that is) and more water can result in 'monster' size bulbs for some mature plants. Although - a plant doesn't need to be monster size in order to get nice flowers. They can be small to medium size, and yet very healthy, and will produce flowers.