slipperorchidblog.com

What do you do when your orchid leaves are flaccid, limp, and just not performing?  How do you get those erect, stiff leaves full of turgor and vigor?

On many occasions I’ve acquired plants or somehow ended up with plants that have a central leaf that just won’t stand at full attention.  I had one particularly large P. rothschildianum ‘Green Valley’ x ‘Fly Eagle’ with lovely thick, wide leaves.  The plant grew well, but at one point the big central leaf just flopped over.  Watering more frequently just didn’t seem to help, despite a pot full of healthy roots (1).

Having grown under lights like the pot growers, I had already experimented with every possible humidifying system you might come across:

Ultrasonic humidifiers:  These are usually cheaply built, with an ultrasonic element that breaks quickly.

Ultrasonic misters:  These are the ultrasonic piezos from the above humidifiers, and they have identical shortcomings.  You can get them in arrays or six elements that can pump put a copious amount of fine fog, but they require a lot of power, and the power supplies are very low quality.  One of them almost started an electrical fire in my home as I was testing it.

Warm steam humidifier:  these have the advantage of warming your plant area, but by the same token, they have the problem of warming your plants when you want it to be cool.  Good for use in the winter if you want to keep plants warm and provide humidity.

Gravel trays:  Heh…  I’m somewhat unconvinced that these work.  Here’s why: When molecules of water evaporate from the surface area of the gravel, they will disperse into the overwhelmingly greater volume of air that is not already humidified.  Hence, the amount of actual humidified air around your plants is quite low especially if your room is large compared to the size of your gravel tray.  How much actually reaches your plants and has an effect is questionable.  If your plants are sitting in water in a gravel tray and thriving, I wouldn’t exactly assign the success of said growth to the gravel trays, but to semihydroponic growth (and a plant that has adjusted well to it).  Nevertheless, if gravel trays work for you, keep it up.

Cooling misters:  These are the plastic tubes with fine nozzles that you get at Home Depot and hook up to a garden hose spigot.  They claim to produce a mist that can reduce the ambient temp by something like twenty degrees (which only works if you’re in the hot desert and dropping 20 degrees gets you down to a balmy 90 deg F).  The problem is that the mist produced is not as fine as you might think, and actually ends up splattering droplets all over your leaves coalesce into big drops that then run into the crown of your plants, forming a lovely cesspool for erwinia and other pathogens to grow and infect your plant.

So, what is going to get those limp leaves up?

I use, and love, The Hydrofogger (2).  This thing pumps out a super fine, atomized mist like nothing I have ever seen.  It works on a different principle than any of the above.  A centrifugal mechanism inside throws water out onto some other thingamajig that results in the finest, loveliest, most ethereal angel mist you can imagine.

If you can use one of these babies in an enclosed space like a small 15′ x 15′ greenhouse and jack it up to full capacity, you will have an area completely packed with fog.  I’ve gotten the fog so thick that I literally could not see more than a few inches in front of my face.

So how did my limp roth do?  Well, I subjected it to a few days of 90%+ relative humidity, and that limp leaf just rose and became erect as if I had fed the plant a bottle of Viagra (not that I have any personal experience or need of such pharmaceuticals).

Other plants that didn’t have limp leaf problems also seemed much happier, too.

Please keep in mind that the other part of this equation is having an enclosed space that can hold the humidity at the required level.  (So if you’re growing on a patio, you may want to try hang some plastic sheeting around your plants to keep the humidity high)  Venting the humidity from time to time, and keeping strong air movement flowing over your plants will help to prevent other opportunistic pathogens from getting a foothold.

=============

(1) So why doesn’t simply watering the plant more work better?  There is probably a limit to the amount of water that can be pumped through a plant’s vasculature system from the roots.  Increasing the availability of water in the air allows the molecules of water to be absorbed through the leaves and possibly reach areas not reached as efficiently by the plant’s vasculature.

(2) Call the Hydrofogger phone number at 1-866-77-HUMID, and ask to speak with Mr. Thomas.  He will take good care of you.  Full Disclosure: I was so pleased with the results, I told Mr. Thomas I’d mention Hydrofogger on this blog, and he kindly agreed to give me a commission on any sales originating from my referral.  I’d like to pass on the generosity — if you get a Hydrofogger, you can receive $25 off of your next order with us at Paphiness Orchids.

• Comments Off

One of the most enjoyable things about growing orchids is the learning process.  It’s also one of the most frustrating things as well.  The pressure is even greater because we’re dealing with beautiful, treasured, (and oftentimes expensive) things that might live — or die — because of our choices.

I guess that’s why growing orchids is so addictive: it’s like gambling.

And in gambling, many “systems” abound.  It’s the same with orchids.

So how do you figure out what works for you and what doesn’t?  Answer: experiment.

While most of us know what an experiment is, not all of us know how to do a proper one that enables you to draw a strong conclusion.

Many well-meaning growers will rave about how switching to a new media/fertilizer/light source/etc  revived a long-dormant plant, resulting in a blooming that caused AOS judges to swoon and give the plant an FCC.  We’ve all heard (or told) stories just like this.

But the question is: how do you know this didn’t just happen by chance?  The world is a very complicated thing, especially when it comes to biology.  Weird, unexpected stuff happens all the time in experiments.  And experiments performed on one single plant can always be attacked on the grounds that the observed result was due to chance, or some other unexplained phenomenon.  The revival of the long-dormant plant could absolutely have been due to whatever change you subjected the plant to, but how do you prove causality?

That’s when you need a well-designed experiment.  A well-designed experiment helps you to conclude that the results obtained were not due to chance.

Here are key steps to doing a solid experiment.

0) You need a control group and an experimental group.  The control group is the one that is treated normally.  No new media or fertilizer or anything.  The experimental group is the one that gets the change in conditions that you’re trying to assess.

1) You need a “useful” number of plants to compare.  A result from testing one plant is not enough from which to draw a strong conclusion.  Ideally, you’d want something like 15 - 30 plants in each group (which is what professional plant researchers try to do).  Of course, we don’t all have the space or resources to do an experiment on that many plants.  For the typical grower, I suggest around six plants in each group.  That means six plants in your control, and six plants in your experimetal group. (I know, I know…this requirement is NOT easy for most home growers.)

2) The plants should be preferably from the same cross.  For example, if you’re testing a new media for growing rothschildianums, ideally you should use siblings from just one cross, such as ‘Rex’ x ‘Mont Millais’.  But if you don’t have six from one cross, at least try to get six similarly-sized roths.

3) Focus on only one variable at a time.  This is a hard one, and requires some self-discipline!  If you’re testing a new fertilizer, don’t change the media as well.  Vary only one variable in the experiment.  Otherwise, your results will always be haunted by the specter of uncertainty of whether that one variable really caused, by itself, the result you observed.

4) Measure, measure, measure (and compare your control group to your experimental group).  How many new root tips?  How many new leaves grew?  How much did leaves elongate?  How much did the plants weigh?  Measuring is objective, and banishes, or at least pushes back, subjectivity from the analysis.  Yes, I know this is a pain, but the more of this stuff you do, the stronger and less assailable your conclusions.

Anyone who has read about orchids on the internet knows that advice and opinions abound.  Doing proper, well-controlled experiments lets you cut through the crap and determine for you and your growing conditions what is likely to work best.

• Read comments... (1)

What do boxing, figure skating, gymnastics, and orchids all have in common?

(Hint: It’s not athleticism.)

Answer: In competition, they’re all judged by people. Sometimes people with divided loyalties.

A friend of mine brought a P. spicerianum in for judging, a truly beautiful specimen.

The judges looked at it. They squinted at it. They snorted and harrumphed. Then they declared it a hybrid, not a species, and would not judge it for an award.

They gave the following reasons:

1) The width of the leaves. They’re too narrow.

I’d suggest that these judges take a refresher course in genetics. Variation happens in all natural things. Leaf width will necessarily vary as a result of genetics. Some people have long earlobes, and some short. Some have long pinkies, and some don’t. If you look at enough of anything biological, you will find outliers. The variation in biology is built-in.

Variation can also result from environment. I have had plants that I acquired with leaves that were quite wide and round, and on subsequent growths, the leaves narrowed. No change in genetics, simply a change in the type of light.

2) The way the dorsal looks. It’s the wrong shape.

3) It has green spots on the staminode, a certain sign of its contaminated hybrid lineage.

Hmm… I would’ve thought they’d give a plant the benefit of the doubt, and judge it as if it were a species plant since it’s plain that not all judges are professional taxonomists (nor does anyone expect them to be). The award could stay provisional until submission of taxonomic verification.

Or do you need to bring verification from a taxonomist prior to the judging? Seems that with some judges, that might annoy them even more.

Well, I looked into the staminodal question. And here’s proof that P. spicerianum species plants — identified and confirmed by a professional taxonomist (it’s in his book!)– can and do have green spots on their staminodal sheilds:

From Braem & Chiron, Paphiopedilum (2003), p. 169.

• (0)

You hear about nitrogen in fertilizer a lot.  While everyone knows that plants (and pretty much all living things) need nitrogen, most people don’t really know what plants do with it.

Nitrogen is an element.  An element is a chemical substance that cannot be broken down any further without losing its essential nature.  You can break up a nitrogen atom into electrons, protons, and neutrons, but then it is no longer nitrogen.

Each element can be likened to a unique Lego piece.  Just as Legos can be joined in infinite combinations of shapes and colors, elements can be joined in an infinite number of chemical compounds.

In living things, nitrogen is one of the most common elements.  It is found in DNA, RNA, and amino acids, all of which are needed for life.  So when your plant is growing, it must mean your plant’s cells are dividing.  If your plant’s cells are dividing, then that means:

1) they’re making proteins which means they were making amino acids for the proteins

2) they were making RNA in order to make the proteins, AND…

3) cells are making more DNA to run the show

Some plants (but not orchids) have the ability to “fix” nitrogen from air (FYI: air is 78% nitrogen).  “Fix” is just a fancy term for putting nitrogen atoms into compounds that are readily usable by living things.  Plants can take nitrogen in the form of nitrate (NO3-), as well as ammonium (NH4+).

So if your orchids can’t get enough nitrogen, then they won’t be able to make amino acids for proteins, nor RNA, nor DNA.  And they’ll stop growing.  Nitrogen, like the better-known element carbon, is an essential building block of life.  Make sure your plants get it!

• Read comments... (2)

In this heretofore long-winded explanation of what happens when a plant “rests” for a season, we’ve reviewed some basic molecular biology.  Hopefully concepts like cells, molecules, DNA, and enzymes are more clear now.  If not, here’s a one sentence refresher:

Cells are biological units containing many kinds of molecules, DNA being a specific kind that tells the cell how to make enzymes, the molecules that do the work of a cell.

One thing that cells (and hence the organism they are a part of) do is adjust to changing conditions.  And in nature, nothing is more constant than the changing of seasons.   When winter approaches, certain enzymes of the cell monitor the shortening of days and the drop in temperature marking the approach of cooler weather.

Your typical enzyme molecule works with others of its same kind in a sort of gang on an assembly line, getting handed some tweaked molecule from the enzyme upstream,  which they then tweak themselves, and then passing it to the next guy down the line.  Sometimes, believe it or not, the enzymes tweak themselves and pass themselves down the assembly line!

Here’s a classic clip from I Love Lucy that I hope will illustrate the assembly line-like nature of biological processes:

Of course, if you’ve read my previous post, you’ll know that the assembly line analogy falls apart at some point, too, since what you really have are swarms/clouds of a specific enzyme type overlapping in 3-dimensional space other clouds of enzymes or reactants, all carrying on their highly specific work by randomly bumping into each other.  Yes, biology is very, very complex.  (And that’s why there’s still no cure for cancer despite the billions and billions of dollars spent on research.)

Anyways, back to the weather: how do enzymes “know” that seasons are changing?  After all, they don’t actually think, do they?  No, enzymes don’t think.  But they do react — and by react, I mean they are involved in chemical reactions.  And when, say, the temperature-monitoring enzymes experience a change in temperature, they fail to react in the way they usually do.  This makes all the difference in the world.

You can think of the cell as a vast array of different assembly lines/swarms manufacturing and reacting and moving all manner of molecules.  The temperature induced change in reaction rate gets transmitted down the line in what is like a giant Rube Goldberg contraption of mind-boggling complexity, until it reaches some central switch enzyme that controls the change-of-seasons genetic program.  In other words, the information about changing seasons is conveyed to this central switch enzyme, which then turns on all the enzymes that are needed for colder (or warmer) weather or when it’s time to put up a flower.  Just as a football team changes from offense to defense to special teams, so a plant has enzymes for spring, and enzymes for winter (or their relative equivalents in tropical slipper orchid country).

So back to the original question: what happens when you let your plants rest?

My answer is that the plant changes a genetic program.  It’s not because you might otherwise grow them to death.  Plants are designed to grow: that’s what they do.  But part of their growth cycle requires a switch to a different seasonal genetic program, which entails production of a bunch of different enzymes.  And the plant likely needs those enzymes to get made and do their thing for long-term health.

It’s kind of like those claims that your plants (or you) need trace elements such as selenium or molybdenum for health.  Some species of orchids need the change in seasons to cause the change in genetic program to cause the production of certain enzymes to do specific things so they’ll grow well and put up a flower for you.

• (0)

Most people have a good idea of what a cell is.  If you need more background, you can look here.

Here’s my working definition: A cell is a self-contained unit filled with everything it needs to make a copy of itself and do a specific job (assuming it’s part of another organism).  Inside the cell are armies of what I’ll call “molecular machines” that perform various chemical reactions.

Biology is a bit like quantum mechanics, in a way.  In quantum mechanics, if you keep peering deep enough, you’ll find that your “real world” intuition falls apart.  Stuff gets weird and counter-intuitive, and all kinds of oddly named particles get involved.

In biology, an analogous strange situation holds.  A useful word to keep in mind here is “swarm”.  Each bee in a swarm chasing you is the same as every other bee and they have one unifying goal — driving their stingers into your flesh.  A cell is full of multitudes of different swarms, each composed of identical molecules(*).  Every molecule in a collective swarm seeks to do its specific job (usually some specific chemical reaction).  The way things get done in this dance of swarms is by, believe it or not, bumper car-like collision.  Yep, what we observe as the exquisite and astonishing organization of living things derives from intersecting swarms of molecules colliding and reacting with other swarms(**) of molecules.  Absolutely amazing.

So what is an enzyme?  I’ll probably cover this in more detail on some other slow news day, but for now, suffice to say that enzymes are biological molecules — molecular machines –  designed to do a specific job.  Slap a methyl group on here, chop a hydroxy group off there, string some nucleotides, shred RNA, make ATP; all of these and myriad others performed by specific enzymes at specific times and places.

Enzymes pretty much do the work of the cell.  They are the worker bees, the factory workers on the floor, the office drones in the giant bureaucracy.  And the work of the cell is chemistry: chemical bonds synthesized and broken, on and on, propelled forward by the light of the sun.

So how does the cell “know” how to make enzymes?  Ahh, that’s the secret.  Well, it’s no secret, really, just that most folks get confused and intimidated by all the scientific terminology.  Here it is:

The DNA is the blueprint/the software/the plans for making enzymes.

That’s pretty much DNA’s main job, acting as the cell’s how-to manual for making the molecular workers that do the jobs inside a cell.  In orchids (and all plants), there are enzymes that make pigments, enzymes that fix DNA, enzymes that make cellulose, enzymes that destroy other enzymes, and enzymes that monitor the passing of the seasons.

And that brings us back to my original subject: what happens when you let a plant “rest”.  That’s the subject for my next post…

(*) OK, so what’s a molecule?  I think of a molecule as a grouping of atoms that has unique characteristics.

(**) The swarm analogy breaks down when you notice that enzyme molecules, unlike bees, don’t have brains.  They simply collide with other molecules.

• (0)

If you’ve been growing orchids for awhile, you’ve probably heard that some plants need to rest from growing during the winter (or other season).

I’ve always found this to be puzzling advice. Plants, like all biological life(*), are made up of cells. Think of a cell as an autonomous factory capable of taking care of nearly all of its own needs. As long as the raw materials are present, and it is not irreparably damaged, and it is getting the green light from whatever other cell might be bossing it around(**), it can continue to grow, repair itself, and pretty much do whatever it was designed to do.

One thing that most cells like to do is replicate themselves. You’ve probably heard of cell division (a.k.a. mitosis). Cell division is how living things grow. You start with one cell, which divides into two, then into four, and so on, and so on, and so on. Of course, at some point, some cells stop dividing according to the organism’s genetic program.

But why should a plant need a seasonal “rest”? What is it resting from?

Take us humans, on the one hand… We get up, eat, drink, sleep, reproduce (or try to). Our cells churn away making energy for all of those important activities we engage in day to day. They also divide so that we grow and repair ourselves. But our bodies do wear out, and in our cells, after each cell replication, a small chunk of DNA gets lopped off the end; past a certain point, the cell just dies. It’s the cell’s way of marking time. Hopefully we get to reproduce before that genetic clock shuts us down.

On the other hand, an orchid plant’s job is pretty much to grow, and look attractive (whether to bug pollinators or society judges, both justifiably regarded as pests in certain circles). If the plant has light, water, carbon, nutrients, etc., it ought to be able to simply keep growing, pretty much forever.

So why do orchid plants need a rest? Why is it that many growers claim that you need to keep your plants from growing themselves to death?

Well, this post looks like it’s going to be much longer than I thought, since we’ll need to talk about cells and enzymes first…  And that will be the subject of my next post.

(*) I’m not entering the debate on whether viruses, either biological or digital, are “alive”. That idea has been argued to death elsewhere (no pun intended).

(**) Yes, even cells have bosses ordering them around. Sometimes many different bosses.

• (0)

It’s quite easy to pollinate a slipper orchid. Obtain pollen from the pollinating plant on the flat end of a toothpick, and then spread on the pollinating surface behind the staminode.

Wait 6 - 12+ months until you obtain seed, and then plant the seeds in an appropriate place. If you’re in the jungle, probably just letting the wind blow the seed away will work well enough, since that’s exactly what happens in nature. One seed pod can produce many thousands of seeds on a good cross — the vast majority never make it, but enough do that the species can continue.

Before the development around 1920 of chemically defined, sterile laboratory based media (looks like white or black Jello) for orchid seed germination, orchid cultivators would sprinkle paph seeds onto the media surface around the base of the parent plant. A few seeds would germinate, and result in plants that would put out leaves, grow roots, and follow the natural cycle of plant development. I haven’t tried this myself yet, but it’s definitely on my list of experiments.

Seeds of other plants ranging from trees to carrots to beans all carry their own energy storage in the form of starch. Orchid seeds, on the other hand, do not carry their own energy storage resulting in extremely fine, dust-like seeds easily carried by the wind. While the orchid plant is still just a seed without leaves to photosynthesize for energy, the seed gets its energy from fungi called mycorrhizae. While mycorrhizae is not a household term, these microbes are probably one of the most important fungi on the planet (more on these in a future post) since they are intimately involved in plant growth just about everywhere.

Mycorrhizae provide the initial sugar the orchid seeds need to germinate. The fungi enters into a symbiotic relationship with the orchid seed, producing sugar for the orchid seed to grow leaves and roots. In exchange, the developing orchid plant produces substances which the mycorrhizae uses for its own growth. Once the plant puts out leaves, it can begin photosynthesis and produce its own energy although the mycorrhizae continue to play an important role. And that’s something we’ll look at in a future post.

• (0)

I hold that the original Star Trek series was still the best of all the Star Trek shows. In one very memorable episode, “Let That Be Your Last Battlefield,” the Enterprise encounters the last two individuals from the planet Arianis. These two men are of different races: one is solid black on his left side and white on his right, while the other is the opposite. They are sworn enemies, and one has been chasing the other for 50,000 years. (!)

Here is one of the gentleman from planet Arianis:

And here is a Paph that must have come from the same planet (scroll down!):

S

C

R

O

L

L

_

D

O

W

N

Notice the near perfect split down the middle of the flower, the stem, even the ovary (i.e., the seedpod thing)!

What genetic accident happened to produce this freak of nature? What can we learn? Can your plants avoid this awful fate?

That’s for another posting…

• Read comments... (1)

(If you missed the first post about ploidy, click here.)

Does increasing ploidy actually work? Like many things in biology, the answer is yes and no.

Increasing ploidy is a kind of blunt-instrument way of jacking up the number of genes that do something desirable. For example, a normal diploid plant has two copies of, say, the gene that produces red flower pigmentation. By doubling ploidy (e.g., increasing the number of chromosomes from 2n to 4n), you’ll have double your original number of red pigmentation gene copies: you started with two, but now you have four.

The idea, then, is that you’ll get more red pigment produced.

Here’s a way of looking at it:

Imagine you are looking for a new flat screen TV at Best Buy or someplace like that. Imagine also that on one wall there are 50 TVs, each one set to a different channel, and to a different volume. Let’s say The Simpsons is playing on one of the TVs.

Let’s increase the “ploidy” of the TV showroom by DUPLICATING the wall of TVs, all with the same shows and same respective volumes. Now, there are 100 TVs, and 50 shows playing.

What you have now is a double dose of each show on each TV. You’ve got twice as much Simpsons blaring out at you as you had previously.

A similar thing happens when you increase ploidy — you increase the number of genes and what the genes make (called the “gene product” which is usually a protein).

So if you increased the number of genes involved in making red pigment by increasing the number of chromosomes, you are that much more likely to have redder flowers.

But, at the same time, you’re increasing the number of copies of all the other genes that do stuff in the plant, too. This may have a positive effect, a negative effect, or zero effect. Like so many things in biology, it all depends…

• (0)