Thursday, February 14, 2019

My Year of Orchids: More experimenting with fertilizer

I broke down today and bought some epsom salt (magnesium sulfate). “Why?” You might ask. I’ve been reading a bit on this substance which has, it seems, no substantive orchid research behind it! Kind of interesting.

But as a botanist I know that magnesium is the central ion of every chlorophyll molecule. It is primally, absolutely essential to photosynthesis. And many of my orchids have been yellowing, meaning they are doing less photosynthesis than perhaps they should. A signal perhaps that they are lacking chlorophyll or not synthesizing chlorophyll as they must, possibly because of a lack of magnesium with which to build the chlorophyll. Incidentally. And I hope you are interested in this as much as me. Or at least a little bit:

The biosynthetic pathways of hemoglobin and chlorophyll are identical, identical! for the first twenty or so steps. Later iron is substituted in hemoglobin for the magnesium in chlorophyll. These essential molecules, hemoglobin (in us) and chlorophyll (in plants) are not-distant cousins.

Anyway. I’ve noticed those orchids going yellow. First was Miltonia spectabilis, which is supposed to yellow when happy (spoiler alert some of her yellow buds turned purple today. I think I may be a papa soon! Flowers??) but others went yellow too. My browning Broughtonia looked great, then asked me not to water her, and yesterday, scandalously, dropped a leaf. I was I admit in bit of a panic.

So now with warmer days coming on I figured even the shyest of orchids must be getting ready to live their best life. Why not help them accomplish it with magnesium, that all important building block of chlorophyll and, incidentally, coenzyme to so many metabolic pathways in the plant cell. Let’s see where they go with it.

Wednesday, February 13, 2019

My Year of Orchids: Growing every which way

I don’t know how to say it any other way. The orchid roots have gone wild. Cattleya labiata is a good example. She has sent roots pretty much radially across her tree branch. I think if you accounted for the topography up there you could map her root growth pretty much like the outward aiming spokes of a wheel. Great way for her to explore, build territorial rights, and find sources of nutrition, light and water.

Pretty much the same time I noticed this crazy root behavior I observed several other things about labiata. She is glued solid into her tree. Rain and wind pose no challenge. It’s really like she’s “one” with the tree. She has successfully built a crypt of roots beneath her to store moisture and nutrients, and to invite geckos, ants, other insects, and countless microbes in that cool protected space. Cattleya labiata has also grown perceptibly. Her leaves have gotten wider, harder, and much longer. And she’s kind of hanging out of her perch. In search of more light? A random leaning? Time will tell.

Cattleya labiata is not the only one I noticed today. It seems that winter is past and we are experiencing mild days and moist, sometimes densely foggy mornings. If you were an epiphyte I don’t think you could ask for anything nicer. And so my orchids, bromeliads, tillandsias and epiphytic cacti have responded beautifully. Even noticed today an air plant whose leaf tips are becoming just the slight blush of purplish. Subtle yet eye popping!

When we lived in Cambridge Massachusetts I doted over my tiny garden. Just ten feet wide and barely thirty feet long. In winter it was bleak, empty above except for branches and stray leaves of the season before. A few bulbs would start in the spring, following the example of the early blooming witch hazel and my lusty trusty hellebores. By late June it was a solid green, eight or ten feet tall.

I used to ponder. That mass of green, those cubic yards of green developing over four months or so represented not only plant growth. It signified an explosion of bacteria that live in the plants, specifically mitochondria and photosynthetic chloroplasts. All of this had to be choreographed, regulated, and controlled in the plant body at the cellular level, and also in the collective plant community.

Here in St. Petersburg Florida in early February the dead of winter has passed. I noticed a lull in the plants. Two, actually. The fall into hibernation was slow and bumpy. I struggled for weeks figuring out when to water orchids that “should” have been sleeping. Now with the week or two of winter over, there were a couple of days of lag before the orchids woke up. Now I think they are fully present, recharged and ready to take off. They all seem to be growing every which way. 

Tuesday, February 12, 2019

My Year of Orchids: Mycorrhizae-the plant fungus symbiosis in orchids

I knew from what I’ve read that fungi played a role in orchid germination. In that situation the orchid seeds, which lack nutrients of their own, depend on the fungus to supply them with what they need to germinate. I didn’t know that adult orchids also partner with fungi. And I’ve never had the opportunity to observe this in nature. Until today.

My friend Calvin gave me a big mount of Encyclia tampensis. The orchid had been growing on a dead oak branch, which now might be why it started to fail. Oak is good. But the orchids want live wood. The reasons are not clear to me, nor can I imagine how the orchid “knows” it’s on something dead. But nothing these creatures do comes as a surprise.

OK. Lunch at Calvin’s. Big bag with big bunch of orchids and dead wood. Next morning I went to work. The orchid hadn’t been thriving, at least recently, but it occupied a large area of the wood. Enough I’d say for several jumbo handfuls, if you could measure orchids that way. Because it was a big colony I decided to separate it however it would come apart and do a little experiment to see how the different clumps would grow in different parts of the garden. By the way Calvin came over about a week later and did a quick inspection. I think he was satisfied.

The clumps didn’t look too healthy but they weren’t dead. Some good pseudobulbs and stiff leaves and a lot of roots. They went up into the trees on a cold damp week and even as it has warmed up the mornings are foggy and dew is everywhere. So my daily misting is more a “want” than a “need” for the new orchids.

Today I went up close and saw roots on one clump that looked like typical mycorrhizal roots in terrestrial plants. The root tips were blunt, the roots themselves stubby and thicker than neighboring roots. Some were blackish, some whitish, but notably, none of them had the green scum you usually see on older roots.

If these we’re mycorrhizae it’s possible that the fungus was fending off or even digesting whatever green stuff (algae or photosynthetic bacteria) might have landed on the root. And perhaps transferred some of those nutrients to the plant.

Mycorrhizal fungi provide extra nutrients for their plant hosts. Usually the nutrients are transferred from the soil to the plant via the fungus. But what about in a situation where the plant roots are not in the soil, like orchids? The fungus must be making micronutrients available to the orchid in exchange for carbohydrates the orchid produces during photosynthesis. It makes sense that both organisms benefit from this partnership.

Mycorrhizal fungi in the soil go a step further and improve the delivery of water to their hosts’ roots. Partly this is strictly mechanical. The fungal cells (hyphae) are thinner and have more surface area than the plant roots. This way they can penetrate the soil more effectively than the plants or simply penetrate tinier spaces where water molecules are hiding.

What about in epiphytes? The crowning observation I made, the thing that got me really excited, was that fungal-covered roots retained water for longer. A lasting drop of water developed at the tip of every root infected with fungi. It stuck around longer than the water on uninfected root tips. Again, possibly a mechanical explanation. More (fungal) surface area, more water adhesion and cohesion at work.

Another thought. We know that fungal species have lots of different lifestyles, parasitic, saprobic, mycorrhizal, and lots and lots of in between. We know as well that fungi growing on wood have different molecular microhabitats. One wood rotter goes after nitrogen, another digests cellulose, and so on. Mycorrhizal fungi are some of the same wood inhabiting species. What if Calvin’s oak mount was just too old, too depleted to support a healthy fungal community. As the fungal ecosystem degraded and possibly simplified (less species on the log because of less nutrition) the orchid also started losing ground. We’ll have to keep a close eye on these babies and see how they develop over the months now that they’re not on their log. Sorry for the dad humor but LOTS of food for thought here.

Wonderful to observe these details that are actually vital to orchid growth in the wild. What an exciting day.

My Year of Orchids: Tiny orchids

Yesterday’s mail brought an order of about twenty orchids. I knew they were in two inch pots but boy were they tiny! Tiny orchids are a beautiful thing. We saw some a couple of months ago at an amazing exhibit at Selby Botanical Garden. They were part of a large glassed in terrarium and the landscape they inhabited was absolutely magical. But I’m not trying to build a terrarium. I’m planting all my orchids outside. These tiny babies were sure to get lost.

I had to come up with a strategy for placement and retrieval that would kind of help me remember where everybody was. And when I say tiny I mean it. Like smaller than a quarter and nowhere near as shiny. So for my three new jewel orchids, some of the smallest of all, I planted one in a pot, one I planted on the shady side of a large rock in my shade garden, and one I put near the base of a tree with the tag showing prominently. Fingers crossed for those beauties. Also by the way I wanted them in slightly different placements and habitats so maybe one would survive.

I had another terrestrial/litho that’s supposed to grow to a very large size, Vandopsis lissochiloides. It too was teeny so I arranged a big rock vertically and planted it at the base of the rock, so hopefully I’ll keep track of it and the rock won’t fall on it. 

Some of the new babies I put in slatted baskets with their cousins. They are just too small to plant on their own. The smallest, a tiny Bulbophyllum digoelense, I slid into the basket with my thriving Bulbophyllum fascinator. Maybe it will catch on and grow. At least I won’t lose it. A Dendrobium and a Phalaenopsis I put in baskets with very old cousins of theirs that I rescued. The oldies are blooming for the second time this year but they take up less than half the basket. Why not potentially extend the blooming season with these new babies. I’m not the kind of purest who grows specimens on their own for “show.” I’d rather fill up the space with lusciousness.

Speaking of which....most of the rest of my new orchids I stuck among bromeliads or air plants just so I’ll remember to mist them but also to give them a toe hold in their new world. I think they’ll look great as they complement each other and start to burgeon.

Well as always it’s fingers crossed when new plants hit the trees. I think they were in their box a little too long and just a little squished—my supplier sent me some free no-IDs so the space was really packed. But good news is everyone perked up beautifully an hour or two after they were unpacked and even better, it was a cloudy afternoon, a cool night, and a fog shrouded morning that greeted them in their new home.

Monday, February 11, 2019

My Year of Orchids: Companion plants

We love our lawns. So green and lush and uniform and open. So clean and pristine. But like the dozen or so spider egg sacs Janet found under our couch today, an explosion of hatching we didn’t really want to see, Mother Nature likes things a little more hidden, more complex, perhaps a bit darker. 

I ran across the term companion plants a couple of weeks ago. Yes, in the context of orchids. Strange I thought. Do they need a companion? But then I took a moment to think about the one or two orchids that I stuck in next to a bromeliad or an air plant. They certainly didn’t seem unhappy. I had conjectured in fact that they were somehow “encouraged” by the companion to grow. Hormones in the air? Some sort of secret chemical communication?

Lately I’ve been thinking and writing a lot about the orchid plant shape as a micro ecosystem, a place that encourages pockets of moisture, microorganisms, and nutrients that bolster the growth of the whole plant. It occurred to me that companion plants may offer very much the same thing. A companion plant increases the complexity of its immediate environment. Textures, tunnels, caves, notches, and striations that catch and retain resources. So it could be that companion plants can act as a sort of “nurse plant” that provides the orchid with more goodies. 

Then I thought some more about things I’ve observed, for example a large extended orchid root literally dipping into the body of another plant. I’ve seen this also with an orchid root invading someone else’s slatted basket. Orchids definitely like company.

If we imagine how orchids grow in nature it’s probably like other plants. Not alone as some gorgeous specimen but in a community surrounded by other plants. Not competing with them necessarily, because what we consider to be “competition” usually occurs among same-species individuals that require exactly the same resources. We know orchids grow in symbiosis with insects, fungi, and bacteria. What about on the macro scale with companion plants?

Saturday, February 9, 2019

My Year of Orchids: All systems go

It’s been a bit of a rocky road with my Sobralia, a terrestrial orchid that needs to be planted in soil. This particular one also needs kind of shady conditions according to the grower. It came to me in great shape. I especially loved the sort purple hairs at the base of the stem and along the leaves, which is reflected in its species name, “atropubescens.”

I put it lovingly in a slatted basket with mostly soil in a place among the sea grapes where a nice morning sun lit up the purple hairs and shone through the thin leaves. Maybe the slatted basket was a mistake and maybe I was wrong to mist the leaves, because they started to go brown at the edges and finally die. 

Sobralias are not supposed to be particularly fussy so I knew I must be doing something wrong. I gingerly took it out of the basket and planted in real soil in an urn where I could watch it carefully. I planted it with a nice trailing Pilea that made the whole setup look gracefully sculptural. Sometimes the plants know when you are prettying them up and they respond. That’s science. 

I had read that Sobralias like to drink and I figured with this kind of leaves it might like my home brewed fertilizer liquid. Smelly but gives nice results. When I transplanted I did notice that the roots looked happy so that was a good sign. I fed those roots (and not the leaves) every day with my concoction. After a few weeks a new stem popped up out of the soil. A good sign but I had the feeling we weren’t out of the water yet. 

Then today a sign from the garden goddess as I did my pre-watering rounds (it was a cool dewy morning so no rush to start misting). At the tips of Sobralia’s leaves I observed drops of water, the signal feature of guttation. Guttation in plants happens when the immediate atmosphere is humid. It’s the result of a healthy water column reaching from the roots through xylem cells of the stem and into the leaves. Reverse pressure upward from the roots forces the water out of pores on the leaf. When you see guttation you know you have a happy plant and a well-functioning vascular system. Sobraila is good in its new place, ready to thrive. Now it’s all systems go. 

My Year of Orchids: Promise of the epiphyte garden

I grew up in a home where design was a real topic. My parents, though relatively poor, had furniture from Herman Miller. We kids were taken in car rides to see the architectural work of Mies van der Rohe at the Illinois Institute of Technology and on Lake Shore Drive in Chicago. Less so the great parks of Chicago, Grant Park and Burnham Park, through which, twenty years later, I used to commute by bicycle from downtown to my apartment on Marine Drive.

Those bike rides were the beginning of my landscape awareness, the touch of landscape design as light as a cirrus cloud over Lake Michigan.

When I moved to Boston to work on my PhD at Harvard I visited the Arnold Arboretum several times for classes and later took students there, less for the landscape than for the living specimens. It did occur to me though, especially overlooking the rugged pinetum there, dark with evergreens against a dramatic cumulus sky, that thought had been put into the plantings. Not just what they’d show you about conifers, but how conifers appeared in a quasi-natural setting.

Later when I took students from the Boston Architectural College to Arboretum and to the Boston Fens, I came to realize that the genius of Frederick Law Olmsted, designer of these spaces, lay beyond taming the Muddy River and laying nice curved pathways. There was a vision there of how the plantings would look in ten, fifty, maybe one hundred years. This was fine urban garden design, coordinated to a level where the untrained eye could perceive beauty, grace, and form. Gardens got very interesting to me. For a while they were more interesting than the plants that grew in them.

The promise of the epiphyte garden hangs on these formative experiences. Placing my orchids, my bromeliads, my tillandsias and epiphytic cacti among the Native trees and shrubs I started a vision. Maybe in some years as they grow and extend their presence in the garden these plants will develop a sort of canopy in which a new, wild ecosystem will develop. Maybe as these plants grapple with the space in and above the trees they will introduce a new rhythm of community form, leaf placement, and movement in their woody hosts.

Friends ask if the orchids will weigh down the trees. Will they break off branches? It’s an experiment. We’ll see. But I think we’re safe for a few years. And don’t trees strengthen as their branches grow and bear more weight? Isn’t it possible that this whole endeavor will lead to changes perhaps unforeseen in the garden? As a living sculpture each plant contributes to the shape of the garden as it develops in and with its inhabitants. To me the promise of the epiphyte garden is the dynamic interplay of sun, water, nutrients, and the amazing plants I have the privilege to nurture.