Saturday, November 1, 2008

The root of the problem, ever green dendrobium hybrid roots

One of the problems that you find when you are helping new orchid growers deal with problems regarding their plants is that for some themes there is hardly any information or photos posted. You can find thousands of stunning flower photos but few showing how a healthy root system should look like. To ameliorate this problem I am posting some pictures of how a healthy root system of an evergreen dendrobium of the group of hybrids of sphatulata x phalaenanthe sections. Along with some tips on keeping the roots alive and growing.As you look at the photo please note the following details.

1. There is very little by the way of organic material, the plant is potted in marble chips and the mix is quite clean, no moss, sphagnum or other moisture retentive material.

2. The mix is dry but you see massive root growth.

3. The roots are white and the growing tips are green and all growing at the same time, this is a sign of uniform cultural practices. You see very few dead roots.

4. The mix is firmly but not heavily packed, it has lots of empty spaces but the plant doesn't wiggle in the pot.

5. The bulk of the root mass is attached to the pot not to the mix.The paramount need of these types of dendrobiums is that the roots have access to ventilation and that they experience a cycle of drying. Nothing kills this plants better than tyranny of the evenlymoistness. When watering these plants they need to be thoroughly soaked, drenched even, but then they have to be allowed to dry. Heavy packed mix+heavy watering hand=root death. They need fertilizer but in mild concentrations and frequent applications, root killing high fertilizer concentrations on irregular intervals are sure death.

I know most manuals offer general information on how to care for orchids that is generally good as a starting point but with some of these orchids it pays to look at the nitty-gritty of their cultural needs. As soon as this plant blooms I will post the photos.

Bulbophyllum biflorum flower and two flies fighting over it


These flies are usually quite wary as in the garden there are a plethora of predators that think of flies as convenience food. However it seems the smell of this Bulbophyllum biflorum had them entranced to such a degree that they would not move from the flower even when I approached very closely. When I shooed one away the other one would quickly jump on the flower. When both landed on the flower a scuffle ensued and one was thrown from the flower. I could not help but think of two gunslingers that were waiting to see who would make the first move. I have tried to detect a smell but it I can't smell anything. Perhaps other people who have this plant can describe the smell. I assume it is a fecal smell due to the type of fly that is attracted to the flower. Even though ordinarily I would shoo the flies away as to prevent them removing the pollen and causing premature folding of the flowers, in this case I am going to allow the poor blighters some leeway. The truth is that the life of these flies must be one big and smelly pile of s**t, so if they are trying to get their jollies in much pleasanter surroundings I will not be the one to deprive them of the opportunity.

Friday, October 31, 2008

Arachnis culture



Arachnis Maggie Oei 'Red Ribbon', a hybrid



Arachnis flos-aeris var. insignis, the storied "Black Orchid" is, in truth, deep red

Arachnis Maggie Oei 'Yellow Ribbon" An extremely hardy and common plant in PR



A Vandachnis Coronation is a hybrid of Vandopsis lissochiloides x Arachnis Maggie Oei. It is a slow growing, large sized plant that blooms once a week and produces long lasting leathery flowers that favor the Arachnis parent.

Because of their ecology Arachnis plants can be difficult to culture and bloom if certain things are not done.
1. An Arachnis plant needs a good root system to grow and bloom well and to survive the effects of full sunlight. A young plant with few roots that is grown exposed to full sunlight will grow very slowly and if it blooms it will bloom weakly. So you need to keep the base in the shade in a pot filled with bark and leafmold. A touch of cattle manure can do wonders.
2. You have to replicate the plant's journey to the canopy, this is done by tying the plant to a suitably sturdy post, this should be positioned so that the plant eventually reaches a spot where it is receiving full sun during most of the day.
3. When the plant has reached a height that has the tip of the stem receiving full sun and has started blooming, allow it to grow about two feet more and then bend (but not break) the stalk to the side. The bent stalk will mimic what happens to plants that protrude too much from the canopy. The bent tip will continue growing and blooming albeit not as vigorously as before. But after the tip of the stalk is bent you will notice a new stem growing just under the spot where you bent the stem. Continue bending down new stems and cutting the tips that are blooming too poorly. Plant them near the base of the first plant.
4. Continue planting stems and enjoying the results, give stem props to neighbors so that they can plant their own plants.
5. Enjoy the ever enlarging mass of Arachnis that is decorating your house and your neighbors house.
6. Start getting nervous and paranoid about the sheer mass of orchids that is now growing all around your county. You know they are talking about you.
7. Grab a machete and your loved ones and hack your way out to freedom away from the encroaching ever growing orchids.
8. Flee the country.
9. In your new residence buy an innocuous looking "fast growing"orchid.

Dendrobium anosmum var. huttoni culture




Late last year I was offered a large, two cane keiki, of Dendrobium anomum var. huttonii (it was a particularly fine example of this semi-alba type). It was an offer I could not refuse, as high quality plants of these type are seldom offered for sale. Unfortunately the keiki was attached to a cane of the mother plant that had been bent until it was attached to the mount of the mother plant. This was done to let the keiki attach itself to the fern pole where the mother plant was growing. This meant that removing the keiki would result in a loss of most of its roots. This would result in a severe setback for this young plant and could add years to the wait for flowers. Cutting a piece of the mount was out of question as this would damage the mother plant root ball.Several measures were taken to insure that the keiki would not be set back too severely. These are detailed in the following paragraphs so you can use them if there is the need.It is important to note that what I did can be generalized to other Dendrobiums relatively similar in growth to anosmum such as aphyllum, primulinum, lituiflorum and parishii. However this method might not be advisable with other dendrobium groups.The first thing done was to cut a generous portion of the cane that held the keiki to have as much reserve tissue for the keiki as possible, the keiki was not detached from the cane. Then the unattached roots were NOT PUT IN the potting mix. Roots that develop in the air fare very poorly when buried in the media.These dendrobiums need heavy fertilizing and watering when in full growth, the few measly roots this plant had would not suffice to sustain good growth if it didn't receive intensive care for the first few months. So a creative solution was need to insure the plant got enough humidity and fertilizer, in those critical first months.I made a wire basket with a hole in the bottom. The basket was filled with media that was composed of bark and horse manure. The media was carefully arranged inside the basket. In the center just over where the keiki the basket had (the keiki was very firmly attached so it would not wiggle and damage fragile new roots) a core of very hard, dry horse manure pieces. The horse manure core was put in so that water would drip over the base of the keiki every time the mix got wet. the horse manure core was surrounded by medium size bark so that the plant was provided with an open, oxygenated area where the roots could grow and attach. The bark also concealed the manure which could be an offensive sight for some.The keiki was attached to the bottom of the basket so that the plant would grow and hang like they do in nature. The first few weeks the plant produced a few roots that grew slowly, however as it developed a larger root mass, root production accelerated and it started embracing the media. As you can see in the photos the plant is producing many, many roots and they are rapidly infiltrating the media. The green root tips of the developing roots are quite long, an indication of vigorous root growth. Hopefully this plant will bloom next year. If you compare this potting strategy with a previous post by me on potting of dendrobiums of the spathulata/phalaenanthe group you will notice the strategies are radically different. This shows the need to do some experimenting when growing your own plants and the fact that there is no one size fits all way of growing these magnificent orchids.The brown roots hanging in the air are the original air roots that survived the removal of the keiki from the mount, every other root is new

Dendrobium hybrid culture



Dendrobium Thongchai Gold




Each year vast multitudes of these popular Dendrobium hybrids are sent to that great orchid terracota pot in the sky by well meaning growers. The problem that Dendrobium that are descended from crosses of the Sphatulata and the Phalaenopsis section of Dendrobium pose to the average grower is both perplexing and contradictory. On one hand they are heavy feeders that demand good watering and fertilizing when growing, on the other, overwatering and too much fertilizer are deadly to these orchids. As a result these plants are carefully cared by people who love them in ways that slowly but surely kill them. The first error is potting these plants in an overly large pot, this is a death sentence. These plants need good oxygenation of the roots, a mix that has poorly ventilated spots or even anoxic areas will kill the roots in no time. The best solution is to pot these plants in pots that allow for plenty of air flow. This last week end I was visiting relatives in a seaside area of the town of Rincon. People there cultivate these dendrobiums on palm trunks. Putting most orchids in a palm trunk that has the consistency of concrete, in full sun, in an area subject to strong winds and the occasional sea spray is almost a sure death sentence, these Dendrobium however survive and even thrive. Since a photo is worth a thousand words here are some photos so you can see for yourself how these plants do under conditions that most plants would find too severe to survive.

Bletia patula a pale color form



This flowers show a typical coloration,
they were growing a few feet from the pale colored flower.

A very pale flower of Bletia patula

Every so often I grab my backpack and hike into the island forests looking for orchids. I was lucky enough to secure the company of a friend who is just giving up smoking and was quite desperate for anything that would keep his mind off smoking and him away from other smokers. After a few hours of hiking we came upon a huge area where, for some reason, the all vegetation was killed some years ago by the government. Plants have been slow to colonize this patch but you could see here and there small Bletia patula plants growing inter sped with a host of pioneer plant species, mostly grasses. Unfortunately there was only a single B. patula plant in bloom that I could see in the whole area. When I was photographing the plant my friend calling at me from some distance away telling about a plant that might be an orchid. Looking at the plant from a distance I assumed that probably it was the white form of Spathoglottis plicata, which can be found by the thousands in some valleys in the central mountains. But I decided to take a look just in case. When I got near the plant i realized that it could be a Spathoglottis, it had the wrong shape and the inflorescence was too short. Initially I was quite excited at the prospect of having found an alba form of Bletia patula, however the buds were light pink even if the flower was almost white. I have seen groups many thousands of plants of B. patula in many places in the northwestern part of the island and I have never seen a white form. I might be wrong but as far as I know only one alba form of this species has ever been found. This plant is not an alba, but what it could be called, a near alba, semi alba? I am posting a photo here in the hope that someone who knows more about this species might offer some enlightening comment on this plant. By the way I didn't collect this plant, I can't say I wasn't mighty tempted but decided that it will remain in place until I can ascertain if the government plans to eradicate the plants in the area again. In case that the government has plans to keep killing the vegetation in this spot(I think it is done with herbicides) I will move the plant to a secure place inside a state forest where I can keep visiting it. It is possible that I would have missed this plant completely if my friend had not looked at it closely mainly because I would not have associated the light color flowers nodding in the distance with B. patula flowers.