Cattleya Culture notes

[fred]

Cattleyas are some of the most commonly grown orchid plants, and their culture is often used as the basis for comparison with other types of orchids. The flowers in cattleyas and their related hybrids come in most all colors of the spectrum. Culture varies only slightly among most of these groups; this cultural information is a general guide to "standard" Cattleya culture. Like most other cultivated orchids, cattleyas are epiphytic, or air plants. Because they are epiphytic, they have developed water-storage organs, called pseudobulbs, and have large, fleshy roots covered with a spongy, water-retentive velamen. They are accustomed to being dry at the roots between waterings, and therefore should be potted in very porous, free-draining media.

Light: is one of the most important factors in growing and blooming cattleyas, whether in a greenhouse setting or in the home. Bright light to some sun must be given to the plants, but no direct sun in the middle of the day. This means an east, shaded-south (as with a sheer curtain), or west window in the home, and 30% to 50% of full sun in a greenhouse (3000 to 5000 foot-candles). Leaves should be a medium green color.

Temperatures: Recommended temperatures are 55°-60°F at night and 70°-85°F during the day. Seedlings should have night temperatures 5° to 10° higher. A 10-20 degree differential between day and night is recom- mended, especially for mature plants. Higher day temperatures can be tolerated (up to 95°), if humidity, air circulation, and shading are increased.

Water: should be provided in two ways: in the pot by watering and in the air as humidity. Watering in the pot is dictated by many criteria--size and type of pot, temperature, light, etc. Mature cattleyas need to dry out thoroughly before being watered again. Seedlings need slightly more constant moisture. Compare the weight of a dry pot of the same size and type of medium; it can indicate if a plant needs water. A freshly sharpened pencil inserted in the potting medium can be an indicator of moisture. If in doubt, it's best to wait a day or two until watering. Plants in active growth need more water than plants that are resting. Water below 50° may injure plants, as will softened water.
Cynthia,s Skewer method is a better way of testing than useing a pencil
http://www.orchidgeeks.com/forum/orc...f-orchids.html

Humidity: Cattleyas need 50 % to 80 % relative humidity. This can be provided in the home by placing the plants on trays of gravel, partially filled with water so that the plants stand above the water. Misting the plants in the morning only is helpful in dry climates. Air should always be moving around the plants to prevent fungal or bacterial diseases, especially if high humidity and/or cool temperatures exist. In the greenhouse the humidity can be increased by wetting the floor. Evaporative cooling increases humidity while cooling the air.

Fertilizer: must be given to cattleyas on a regular schedule. In fir bark, a high-nitrogen (30-10-10) formula- tion, or a similar proportion, is used. High-phosphorus or bloom-booster (10-30-20) formulation may be used occasionally (every 4 to 6 applications) to make sturdy growths and promote healthy blooming. When in active growth, plants need fertilizer every two weeks, and when not growing, once a month. Fertilizer can also be applied with every watering at 1/4 recommended dilution. Thorough flushing with clear water every month is recommended to prevent buildup of fertilizer salts.

Potting: Potting is necessary when 1) the rhizome of the plants protrudes over the edge of the pot, or 2) the potting medium starts to break down and drain poorly (usually after 2 to 3 years). It is best to repot 1) just before new roots sprout from the rhizome, 2) after flowering, or 3) in the springtime.
Cattleyas are usually potted in medium-grade potting material, with seedlings in fine-grade. Until a plant has six mature pseudobulbs, it generally should be put into a larger pot and not divided. If dividing a plant 3 to 5 bulbs per division are required. Select a pot that will allow for 2 to 3 years of growth before crowding the pot. Place a small cone of potting material in the bottom of the pot, cut off any rotten roots, and spread the firm, live roots over the cone. Fill the pot with medium, working it in the roots. Pack firmly; stake if necessary. Keep the plant humid, shaded, and dry at the roots for a while to promote new root growth. A vitamin B-l solution may help re-establish plants quickly.

[newbie]

Hi,
I have a cattleya and a paph that aren't doing well. I read your care of cattleyas. How do I ID the dead roots needing trimming? are they the brown ones, and/or the brown ones that have shed part of the outer skin to show a wire like root?

thanks

[fred]

the dead roots will feel very light also brown in color and very soft and dry.
I would trim the roots with parts of the outer ( skin ) off.
When you see your plant root system just feel the roots so you will get to know the good ones as they will be firm to touch.

[butt0n]

So do cattleyas need to have the lower temperature change to encourage flowering like phals? If not, how does one initiate flower spikes on these?

[Cynthia, Prescott, AZ]

Button, some species are triggered by temperature, some to high temps, some to low, and some to day length. Hybrids can be any thing. Generally just don't worry about it, as almost all Catts bloom without any help.

For the culture notes, I know that some people recommend it, but I would definitely not repot by season, as Catts span the seasons for growth and rooting. The critical thing is to either not disturb the roots in repotting, such as repotting when all the mix just falls away when the rootball is being inspected, or always repot when the new growth is just starting its flush of new roots. This is different for each orchid. Some start rooting when the new growth is only a few inches long, and some start rooting when the new growth is fully mature and the plant has finished a resting period. In such a plant, new rooting occurs just about the time the new mature growth (which is just starting to root) starts its own new growth. Therefore, it is possible that two different species that produce a new growth at the same time, might have rooting take place 8 or 9 months apart, and it is the rooting that is the important factor in when to repot. Of course hybrids can have this same variation, but in an unpredictable pattern depending on which of the species are dominant.

On the subject of testing the moisture in a pot, I would highly recommend not using the freshly sharpend pencil, as sharpening is not really a method of sterilization. Anytime an object is poked into a pot with the attendent possibility of stabing roots, it should be sterile. So a new unhandled barbeque skewer is a better choice. There is a spectrum of things one can do to avoid the transfer of virus, and we each have to decide how far out on the gausian curve of effectiveness vs. effort we want to go and how important it is to us that any one plant be protected from acquiring virus. In my case, I could do better than I do, but I try to at least get the high probablility causes of virus in check with the obvious things.

[Aleksa]

Do Cattleyas require dormancy period during winter months?

[kmarch]

Cattleyas come from Central and suth America where they don't experience much of a winter. I grow mine in the same conditions year-round.

[Charles]

I have also been told to let Cats rest like Den. Little water in Oct-Mar. Any truth to this?

[kmarch]

I've never given a Cattleya a dry rest. I've always watered consistently year round.

[Cynthia, Prescott, AZ]

I also don't give a rest to my average Catt. One exception to this is my amethystoglossa, which is particularly sensitive to what goes on at the roots. So I make sure it is very dry before watering, and will probably be even more particular about this when it is not growing, like right now. I have heard they are high light plants, but when I took the shade cloth off the GH a couple of weeks or more ago, the several layers of plastic sheeting giving some reduction, I got a lot of red spotting on a leaf, more than I am happy with, and have move the plant from the west side of the GH to the east side. Hmm, I think I am getting off the subject. Well, maybe not. I have heard that the bifoliates like to dry quickly, and I would think that they would be particularly picky about this when not growing. I have been shifting all my bifoliates and my rupicolious Laelias to clay pots to speed drying, and boy does clay speed drying. I have to water them 2 to 3 times as often.

[missmegan]

My catt. is growing in a wooden basket and the roots are growing/attaching to the basket. How would I repot?

[Orchidflowerchild]

Megan: the point of a basket it sortof to eliminate the needt o disturb the plants through repotting. If the media starts to go to pot, you can just tease it out with your fingers or a waterhose, or something.

As for drier rests, some of the species do need a bit of a dry off. C. walkeriana, nobilior and a handfull of the other Brazillian bifoliates come from central parts of brazil, where the rains slack off for the winter months, but humidity is still high. The plants get moisture from mists and dews and the occasional rain, but in essence, they go dormant and take a rest.

Some of the upland labiate species, especially C. aurea, dowiana, rex and warsewiczii have a similarly drier winter, which also includes a concurrent increase in light, as they live among tropical hardwoods which lose some or all of their leaves in the drier season.

For both of these groups, the drying off is nowhere near as severe as, say, a Nobile Dendrobium, which are subject to very clear-cut wet/dry cycles due to monsoons and their mountainous habitats. I just make sure that those plants are completely and thoroughly dry, between waterings, and I don't water as heavily as I would during the growing season. Hybrids, especially complex ones that involve species that have no drier winter should be treated pretty much the same, all year. In short, Cattleya-alliance plants do not need a dry rest, per se, but there are a few plants that will benefit from being kept drier when not blooming or in active growth. Many people find C. dowiana very challenging and suceptible to rot, until they learn to respect the dormancy and allow the roots to completely dry off, in winter. After all, if a plant is not actively growing, it is going to need significantly less water than when it is. all that fast growth and plumping up and such is driven by water filling vacuoles of the cells and stretching them to their ultimate size. The fact that the plants retain their leaves, though, does say something about their "dormancy." Leaves do transpire and pull water up from the roots, so the plant needs enough to maintain those leaves and not get too wrinkly looking in the pseudobulbs.

Again, though, this is very specific advice for a few species that do experience a noteable seasonal shift. This information does not extrapolate to all Cattleya-type hybrids, or even all Cattleya species.

-Cj

[missmegan]

Thank orchidflowerchild

[kevycatt]

Originally Posted by butt0n

So do cattleyas need to have the lower temperature change to encourage flowering like phals? If not, how does one initiate flower spikes on these?

Dont believe all you read, phals do not need lower temp to initiate flower spikes. In fact my experiments have demonstrated that light intensity change initiates spiking in phals.
Species cats are generally seasonal flowerers and obviously spring flowerers wouldnt be initiated by a drop in temp, probably daylight length in this case. With hybrids the genes have been mixed so we now have cats that grow and flower with no regard to the season. So it really depends on the parents.

[fred]

hi kevycatt
please feel free to go to our Introduction Section and introduce yourself to all of our orchidgeeks

[JLu]

Fred started this thread with a pretty good general Cattleya culture recommendation. Unfortunately it's very hard to be brief and cover the cultural requirements of a genus that ranges from Brazilian Atlantic coastal regions from slightly south of the equator to the Tropic of Capricorn, from inland Brazilian regions that undergo extremely dry seasons, the area of Manaus 1000 miles up the Amazon essentially on the equator, and the mountainous regions of Venezuela and Columbia and central America. These roughly 46 species of unifoliate and bifoliate Catts come from a diverse set of environments. Cynthia pointed out very well that Catts must be repotted when they start to root and that covers the whole year. Some root before bloom and some root after. Orchid Flowerchild (who flat knows her Catts) pointed out how differently some of the species must be viewed in terms of watering. The only generalization that works is that they should drain very well and dry between waterings. Unfortunately one must be more specific. As OFC said..dowiana and dowiana aurea will croak under watering conditions that are alright for most of the others. Walkeriana and nobilior are variable in their blooming patterns and in the site of bloom stalk initiation (sometimes from the bottom of the PB and sometimes from the top). These plants must be managed individually and closely.

Hybrids that have been selected in cultivation will usually be more tolerate to every condition than species. If you want to grow species Catts, you need to read some good Catt literature and not depend on the unreliable and diverse answers you will encounter on an internet board. I can suggest the following:

Orchid Digest Vol 68(4) Oct, Nov, Dec 2004 (available from Orchid Digest) A very detailed cultural article from William Rogerson.

American Cattleyas by Courtney T. Hackney (currently in print)

The Cattleyas and Their Relatives Vol I by Carl Withner (out of print but occasionally available used. I bought it last year for $75 but recently $150 is the going price.

The Brazilian Bifoliate Cattleyas and Their Color Varieties by J.A. Fowlie,MD. If you are really a Catt nut this is a must. It is out of print and seldom available. I got a copy for $175 last winter but you must be persistent to find one.

One other point...Someone said that Phals can be grown the same all year long and Kevycatt said quite emphatically that Phals do not need a day/night temperature differential for bloom set. At best these are controversial. First the Phals in subgenera Aphyllae and Parishianae are considerably cooler growing than other Phals since they occur in the Himalayas. Aphyllae are deciduous and obviously can't be cultured that same all year. Eric Christenson in Phalaenopsis A Monograph (generally considered a manual for species Phals) says on page 263, "The other temperature consideration is the need for a sharp difference (a swing of 10 to 15 degrees Fahrenheit) in day versus night temperatures............allows the initiation of inflorescences."

Again...when growing hybrids that were selected in cultivation, plants may be more tolerate than species to all cultivation conditions, it's highly risky to make generalizations about the culture of plants in a brief internet summary. The plants just do not cooperate with simple growth requirements. The species are isolated to certain geographical environments because they grow under different conditions than other species of the same genus.

[Aleksa]

I love catts and they are very easy to care but after I got one plant yesterday I have some questions...

I had one telephone call yesterday. One man called me to say that one Cattleya is waiting for me in another town. I went there immediately and returned with one large Catt in bag. When I got It out of the bag I saw that the plant had two old growths out of the pot wit the mass of roots outside. And on the other side of the pot there was another old growth outside of the edge. The plant was very neglected. The potting material was totally decomposed and the plant had around 11 old, mature pseudobulbs and no new growths. I know that Catts should be repoted when the new growth starts but I couldn't wait for that to occur for the mix was decayed and there was great danger of root rot.

So I decided to transplant the whole thing. When I got it out from the pot there was large mass of roots inside. Some were rotten but major part was ok. I saw mushroom (yes, mushroom) growing from the potting mix. I had to damage some live roots in order to remove every piece of old bark. I saw that rhizome was dried in the middle (where the smallest and oldest pseudobulbs were) and the plant cracked in two pieces. I got two divisons, one with 4 old pbulbs and other with 7 of them... I had big problems when putting them in new pots. Distance between growths is big and the rhizome is too long. So when I found the pot which had enough space for 2-3 new growths to grow I realised that it was too deep and too large. The plant would be overpotted in that pot. So i found some shallow and wide container, and I was nervous so I just placed the plant inside and pressed tightly the root ball, I felt the roots cracking... I added bark and pressed firmly. Grr, they are so hard to repot. And even now, there is space for only one new growth... Roots are cracked, plant has no new growts, everything sounds wrong... I think that that will set the plant back but I hope that 7 old pbulbs will do their job with storing nutritiens and water. Will this aggressive intervention set the plant back or it will encourage new growth?

How do you resolve that potting problem? I thought about putting some piece of plastic or wood on the edge of the pot so that new growth can't go outside? This sounds stupid but I'm just trying to find the way to keep the plant inside the pot... I can't find the pot that is wide enough and not too deep.

Excuse me for so long post and bad English...

[kmarch]

Originally Posted by Aleksa

I know that Catts should be repoted when the new growth starts but I couldn't wait for that to occur for the mix was decayed and there was great danger of root rot.

Many people on this forum say the best time to repot a cattleya is when the new growth starts. I politely disagree with them. I believe the best time to repot is after flowering when many catts have a short period of inactivity before new roots and growths start growing. The reasion I prefer repotting at this time is to avoid damage to new shoots and roots while repotting. Some people are careful enough and don't have any problems, but I'm not one of them. It is always wise for me to avoid handling new shoots and roots, so believe it is best to repot during a time when little if any damage can be done.

Originally Posted by Aleksa