watering and fertilizing paphs - Orchid Board

Pokey49 · #1 02-20-2014, 09:15 PM

Figuring out the right amount of water and fertilizer for my paphs is a chin scratcher for me. I admit freely that I am new at this. I bought a paph back in December in bud and it has been open in bloom for a month now. I have been watering it once per week and feeding it with "orchid plus" ina 20-14-13 ratio. It has been doing fine, except now I see the two bottom leaves are turning limp and pale. Since I am new at this I have been checking the medium with a moisture meter until I get the hang of things and do not water unless it appears to need it.

What's going wrong? I don't want to keep repeating any mistake as I just got in 5 beautiful plants from Lehua Orchids in Hawaii. The medium in them is quite coarse and appears to dry quickly, have watered them twice now in a week. Would love to have some expert paph advice.

Thanks in advance

Paul

Rico13 · #2 02-20-2014, 09:43 PM

If the medium is too coarse, the plant(s) may be drying out too quickly. I have all my Paphs is a fine grade mix. You have to remember that these plants are mostly terrestrial, or growing on moss covered cliffs, in fine gravel or dirt. So they will need a finer mix to keep them moist.

Pokey49 · #3 02-20-2014, 10:34 PM

I dont think I want to be repotting them do I? They are all in bud and some about to bloom, the one paph I noted above is in full bloom. The mix they are in is what they came in from the nursery I got them from.

AvantGardner · #4 02-20-2014, 10:42 PM

Sometimes paphs "borrow" nutrients from lower leaves just before blooming. This is a natural process and I wouldn't worry too much about it, unless it starts to take entire unbloomed growths. What kind of temps and light are they getting? It is possible you are fertilizing too much and burning finicky roots. How often are you fertilizing and at what strength?

Pokey49 · #5 02-21-2014, 02:02 AM

My orchids are in our sun room. which offers plenty of light but not direct bright light this time of year as its on the north side of the house. The orchids sit along the north wall. I keep the sunroom between 60 degrees at night and 70 at day. I am fertilizing 1/2 strength with the ratio noted above 1x per week and flushing to get the salts out every 4th-5th week with plain water that is luke warm. My other orchids (Phals, cyms and epidendrum) look fine. Its this one paph that the lower leaves are looking poorly and I dont want to duplicate on the 5 new one sI have, whatever is going one

NYCorchidman · #6 02-21-2014, 11:18 PM

Are they in bark? Almost all of them do I think.
How big are your paphs? Single growth?

Let's say, they are single growth (or perhaps with one ore two small new fans attached to the main fan)plants potted in bark, which look a bit chunky.

Well, chances are that the top may appear dry but the inside the pot is still wet.

A good way to judge is to lift the pot and feel the weight right after watering. Then lift the pot and feel & compare the weight in about five days or so (unless you have really really dry indoor air). It should feel much lighter. You could probably wait a day or two more before watering again unless the plants are actively growing.

Another thing, this is general but I find to be quite common, a single growth paph (depending on the cross, so what did you get?) may not have too many roots and they are often found on the top quarter of the pot height.

I mist almost daily so the shallow roots will stay well watered without wetting the entire pot. Then I would water the entire pot maybe once every ten days or so.

Once flowers are all gone, I repot my paphs into clear plastic pots, so I can see and know the root activity and how moist the mix is.

---------- Post added at 10:18 PM ---------- Previous post was at 10:16 PM ----------

Quote:

Originally Posted by Pokey49

My orchids are in our sun room. which offers plenty of light but not direct bright light this time of year as its on the north side of the house. The orchids sit along the north wall. I keep the sunroom between 60 degrees at night and 70 at day. I am fertilizing 1/2 strength with the ratio noted above 1x per week and flushing to get the salts out every 4th-5th week with plain water that is luke warm. My other orchids (Phals, cyms and epidendrum) look fine. Its this one paph that the lower leaves are looking poorly and I dont want to duplicate on the 5 new one sI have, whatever is going one

Two leaves going yellow may indicate a problem.

Can you post some picture showing those leaves and perhaps the entire plant?

MrHappyRotter · #7 02-22-2014, 12:48 AM

It's hard to say, without having some first hand experience with your plants and your growing conditions. Here's my input though.

First, you should feed very, very lightly. Whatever fertilizer you're using, whatever feeding rate you're using, and whatever feeding frequency you at, you can almost certainly reduce it significantly. Orchids in general are very light feeders. This is particularly true for plants grown outside of greenhouse conditions.

Of course, I have questions. What kind of water are you using? If you're using rain or reverse osomosis water -- that's good. If you're using tap water, then you can and probably should cut back even further on fertilization.

It's hard to say for sure if your watering regimen is good, but in general, once per week may not be quite enough for most slippers. There are a lot factors that come into play with that, so it's really difficult to say for sure. Personally, I water twice a week, usually Wednesday and Saturday. But what works for my and my plants may not work for you. The factors to consider are the media you're growing in, the sizes of the pots and the sizes of your plants. I think twice a week is a good baseline, though.

This is totally random, and completely without supporting evidence, but my general advice is to water twice a week. If you have a TDS meter, keep the measurements below 100 ppm if possible. Tap water alone typically measures 100ppm or higher. If that's the case for you, then feed at very, very low rates. You might add 1/8 or less of fertilizer once a week.

Not to complicate matters, but ...

Plants that are adjusting to new conditions are prone to dropping leaves. If the plant is dropping lower leaves, that may not be anything to be concerned about, it's natural. As your paph grows, it's going to drop lower leaves. The frequency and severity are the real indicators of whether there's a problem (or not) and realistically, only experience will determine if your plant is doing okay or not.

Plants may also drop lower leaves when they're doing really well. As strange as that seems, new roots and new growths emerge at the base of the plant. As they emerge, they tend to dislodge lower leaves, so those lower leaves often turn yellow, then brown, dry up and eventually fall off the plant.

Sometimes when a plant is preaparing to bloom, it will allocate nutrients to the spike and use the older leaves as a repository of nutrition. So as the spike develops, older leaves are sapped of important foods, causing them to die off. It's a natural process, and noting to worry about.

On the flip side, if the plant is experiencing stress or a lack of certain nutrients (which is unlikely in your case), they will sometimes sacrifice older leaves. Even if you are feeding regularly, you have to keep in mind that some nutrients block a plant's ability to absorb other minerals and nutrients, so even if you're fertilizing the plant, it can still have deficiencies that would cause leaf drop. This indicates that you might be better off feeding less, believe it or not.

To summarize since I know this is a lot to absorb, some things I'd suggest are:

Feed less often at lower concentration.
Water twice a week.
Get a TDS meter, keep TDS at 100ppm or less if possible.
Make sure humidity is 50% - 70%.

Finally: Excuse all typos in this post. It's late and I'm tired, but I thought I might be able to help a fellow slipper enthusiast.

Pokey49 · #8 02-22-2014, 02:47 AM

I think I have attached two photos of the paph in question.

This paph has been in bloom about a month. It arrived at my house the coldest day of the year, it was 8 degrees, but was packed pretty well and appears to have survived, though it took a long time for the bud to develop and bloom finally. I was watering once a week and then started using a moisture meter which showed the bark in the middle of the 4 inch pot to be dry, thats when I went to watering 2x per week, but only fertilizing 1x per week at 1/2 the recommended concentration. Per you Mr.Happy Rotter I should perhaps cut it back to 1/4 concentration. The water I use is tap water that is from my well. Its not city water. The humidity runs 50-60+% its 59% at the moment. temp is kept at 60-70 and the sun room is heated/cooled with a mini-split ductless system that gently blows warm/cool air into the room, so there is good circulation.

MY best guess ot the problem is to much fertilizer. The 6 other paphs that arrived from Hawaii last week seem to dry out pretty quickly. They too are in coarse bark with perlite. I definitely notice the pots feeling light when they are dry, but I have not learned yet to put a lot of faith in that method yet, thus the moisture meter.

If the photo came through you will notice the bottom leaves being pretty pale. To my limited experience so far with orchids this is a water or fertilizer problem?? Curious which one you all think it is.

Being a newbie it seems to me this orchid growing is all about learning the basic requirements of water, temp, light, fertilizer, humidity, potting mix required for the genus of orchids that one likes and it then becomes a calculated effort, and some guesswork, of trial and error until you figure out what works and what doesn't. Losing a few seems to be a part of the learning process though I have not lost any orchids yet. Fingers crossed. I will back off on the fertilizer concentration and continue to water 1-2x per week based on my best assessment of the circumstances at hand

Pokey49 · #9 02-22-2014, 02:50 AM

Oh, one other question . Whether watering 1x or 2x per week how much water do you use? I douse the pot until the water is running out the bottom of the pot rather than just pouring a dab of water in the pot like my mom use to water her African violets. BAsed on what I have read, all the medium must get wet, not just the top inch or so.

MrHappyRotter · #10 02-22-2014, 03:15 AM

Pokey, in many regards, you are absolutely correct, and I'm impressed with your last comment.

Yes, you can expect to lose some of your orchids. It's a natural part of growing. There are too many factors to account for, from growing conditions to genetics, and it's inevitable that some plants will die.

Based on the photos, it does look like the plant in question may be in a potentially precarious situation, but not particluarly alarming (yet). For most healthy paphs, you can expect to have at least 4 healthy leaves, though 6 - 8 is more typical. Your plant looks like it may have 2 healthy mature leaves, 1 small immature leaf and an additional leaf that is in the process of dropping. It's not hopeless, and I wouldn't even call it alarming, but there is a chance that it won't survive considering it's blooming (which uses a lot of energy) and it only has a couple of really healthy leaves.

That being said, the type of paph you have is typically very vigorous so the odds are in your favor. I'd say, keep the temps in the 70F - 80F range, don't overdo the light levels, keep the humidity at 50% - 70% and water twice a week, and I bet your plant will be just fine. In regards to fertilizer, less is definitely more. Even at 1/4 strength, there's plenty of room to cut back. I prefer to feed weakly weekly, but in absence of a TDS meter, I'd recommend that you further reduce your feeding rate to 1/8 recommenend strength, once a month. I know that sounds like nothing and maybe even ridiculous, but orchids and particularly the slippers are very light feeders. I can't stress that enough, particularly if you're unclear on your water quality.

As far as watering, go all out. Drench the pot. Let plenty of water pour through. What I do is pour water through the pots, lots of it, then allow a bit to collect in the saucers. I let that sit and soak for an hour or more, and then I empty the pots. You want to thouroughly flush the pots to help leach out excess nutrients and to allow the potting mix to absorb all the moisture it can. Then you want to let the mix dry out to an evenly moist level as soon as possible, but never let things get dry between watering.