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The How and Why of Water

Caring

Mar 012009

By Ron McHatton
AOS Director of Education January 2009
Copyright 2008 American Orchid Society

More or chids are killed by incorrect watering than by any other reason. There are two separate components to proper watering; when and how. The vast majority of orchids grown by hobby growers are epiphytes, growing on trees above the ground where the light is more plentiful. These plants are adapted to having their roots exposed to light and air so in addition to water, orchid roots need air. The central core of an epiphytic orchid root is covered with a spongy material called velamen designed to store water. When this spongy material remains wet too long, the central core suffocates and begins to rot. Once the roots begin to rot, the plant can no longer take up water properly and a whole host of problems begin. At worst, root rot will spread upward into the rhizome and cause the death of the plant. In other cases, the loss of roots prevents the plant from absorbing sufficient water to maintain the plant in good condition and the leaves will take on a wrinkled appearance. Unfortunately, the symptoms of over-watering and under-watering are superficially similar and the tendency is to increase watering rather than inspect the roots. Overwatered roots will be brown and mushy while those on under-watered plants will be white or gray and obviously dry. Let’s look first at when to water.

When do I water?
Orchids should be watered just as they dry out. This rule applies to all orchids with slight variations depending on whether your plant has pseudobulbs (thickened stems that are designed to store water) or not. Orchids such as cattleyas and oncidiums should be allowed to just dry completely between waterings while orchids such as phalaenopsis and vandas that have no water storage organs should be watered just before dryness occurs. For vandas, this may mean daily watering during the warm summer months. Vandas and ascocendas that are properly
watered will have actively growing root tips at all times. If the root tips on your plants dry up and seal over, you are not watering often enough. There’s unfortunately no magic formula; i.e., water a plant in a 6” pot every 7 days and you’ll be trouble free. This is because your growing area is different from anyone else’s. Humidity, air movement, potting medium (type and age) and light levels all play a role. There are several ways to determine when a potted orchid is almost dry: 1) the surface of the potting mix will appear dry; 2) dry pots will feel lighter when lifted; 3) clay pots feel dry; 4) a wooden stake or skewer inserted into the potting mix will come out almost dry. If in doubt, a finger inserted into the potting mix is perhaps the best tool to determine the moisture content of the potting mix. It will cause no harm to the plant. And remember, fresh potting mix will always dry out faster than the old medium.

How do I water?
How to water is just as important to proper culture as when to water. When orchids are watered, they should be watered copiously. Water should be provided until it runs freely from the drainage holes. This serves several functions. First, thorough, copious watering is necessary to soak the potting medium. In addition, thorough watering helps to flush away the salts that naturally accumulate in the potting medium from the dissolved salts in our water supplies and the fertilizers applied for good growth. Also, this is your opportunity to examine how the potting mix behaves. If you cannot pour water rapidly through the pot, the potting mix is too dense and you run the risk of starving the roots for air. If you see finely divided material that looks like coffee grounds in the water coming from the drainage holes, your potting mix is breaking down and it’s time to repot into fresh medium. At a minimum, try to thoroughly water your plants at least once a month. Finally a couple of notes about mounted plants and those like vandas that are grown in baskets without additional potting medium. First, avoid dunking these plants in buckets of water. This practice very easily spreads diseases. If one plant has a disease, all those dunked in the same bucket of water will have been exposed as well. Also, two short waterings a few minutes apart are much more effective than one long watering. Once water runs off the plant, the roots will have absorbed essentially all they can at that time and excess water simply runs off to the ground. The proper technique is to water your plants and then a few minutes later water them again, always beginning with the first plant you watered. This allows time for the roots of the last plant watered to finish absorbing water before you wet them again. Roots that are completely saturated will be a solid color while those that are not will appear mottled.

Make Your Blooms Last

Caring

Feb 012009

The blooms of your orchids will stay fresh longer if you follow these simple steps…..

Do not let water stagnate in between their leaves as it promotes bacterial rot that may kill plants (Phalaenopsis). Do not let plants sit in water as their roots will rot and the plats will die.

Do not water them too often. Most orchid plants need watering on a regular basis, depending upon the climate. When placed in decorative containers such as baskets and china, they take longer to dry out so stretch your watering intervals by a few days. Water your plants properly.

Do not expose them to drafts, however faint, or forced air heat, or air conditioners. Such drafts will dry buds and flowers in no time.

Do not place them next to or on top of heat sources (radiators, refrigerators, etc.) at these heat sources continuously dry the air around them and this will desiccate your plants.

Do not expose them to direct sun in the middle of the day. Leaves will burn and flowers will wilt. Maintain reasonable temperatures: daytime temperatures from 65 degrees to 85 degrees at nighttime temperatures from 50 degrees to 65 degrees. If your air is dry, mist leaves and buds once or twice a day.

Native Orchid Conservation

Conservation

Feb 012009

by Susan Taylor
Originally published in BellaOnline

Native orchids around the world are in trouble as a result of collection from the wild, habitat destruction, and increasingly climate change. Orchid societies and conservation groups are working to slow this by reintroducing seedling orchids back into the wild where they previously grew. This work has been aided due to the fact that it is now possible to germinate seeds in flasks. It is illegal to take any orchid seed without permissions since most of them are considered endangered, but with proper paperwork and help from local governmental conservation agencies some good work is being done.

Growing orchid seed in flasks has allowed conservationists to start returning wild orchids to areas where they used to grow, but have virtually disappeared. In the wild perhaps one of every 100,000 orchid seeds will germinate, grow and live long enough to produce seed. The seeds are like dust and can be carried by the wind great distances. But, since they are so small they do not contain food to sustain the growth of the nucleus and require specific fungi to sustain them in a delicate balance between the two. If the fungi grow too fast they kill the seed and eat it; if the seed grows too fast and there are not enough fungi
to sustain it, the seed dies. It is an amazing natural process!

When grown in a flask in the proper medium, up to 90% germination can be achieved. The plants are then treated like any other orchid and grown to planting size in flasks and then transplanted into community pots and then individual pots. There are a number of organizations such as the Native Orchid Conference which promote orchid conservation and provide a forum for those interested in the subject to gather.

Orchid societies around the world are using their expertise to help re-introduce native orchids by growing seedlings and then placing them back into areas where they once grew. Since these efforts are still new, the results have been mixed. But with more and more people trying different ways to do it we are hopeful that trial and error will produce some success stories that others can emulate.

There are some really interesting stories, both on conservation and habitat destruction – which is one of the main causes of the loss of native orchids around the world – at the Orchid Conservation Coalition website.

Why Won’t It Bloom?

Caring

Dec 012008

The usual reason is lack of light. Many new growers take the term ‘houseplant’ a bit too literally and presume that the phal will need about the same light that a foliage houseplant needs…and then despair at the lack of flowers. Fact is, if the phal is given too little light, it will vegetate very nicely and produce pretty, dark-green leaves…and nothing else.

Asking the new grower to guess at what 10% of full sunlight looks like is a bit much, but a reasonably close estimate can save you a whole growing season that may be needed to show that a given spot has not enough light for the plant to flower. One thing I really fret about is that some new growers will give up during that first season and try something else.

So, the guess at what is enough light to make a phal flower is an important guess. If you have to guess on the wrong side of 10% of full sunlight — which is what the phals need to bloom — guess on the high side.

Let me qualify that comment: ‘A little on the high side’.

A little high gets you –
yellow-green leaves and small flowers

A lot high get you –
a sunburned or even a dead plant

A little on the low side gets you –
sparse, but large flowers

A lot on the low side gets you –
no flowers, but a pretty, green plant

The phals will tolerate considerable overdosage of light before getting into any trouble. I’d rather see new growers overdose them a little than underdose them, because at least they see the flowers.

I have never known a new grower to overdose a phal on light except by leaving them in direct sunlight and heat in a parked car with the windows rolled up. When that happens, ZAP! The plant is dead.

There are a few other reasons why a phalaenopsis orchid will not bloom given the other recommended cultural conditions, but they are infrequent. Flower spikes may sometime fold and collapse when splashed with cold water in winter. Immaturity or poor health of the plant, of course, will usually deter flowering. Sometimes a plant will flower while it is in bad health as an act of desperation…to keep the species alive. It’s a pathetic sight; the poor thing trying to carry on by flowering even when the flowering may rob it is strength it needs to stay alive. I’ts a jungle out there.

Don’t let it happen to your plants. If a sick plant throws a flower spike, cut it off at the base and nurse the plant back to health before allowing it to flower again.

Orchid Growing Tips #24

Caring

Dec 012008

by Susan Taylor
Originally published in BellaOnline

Change your watering and fertilizing schedule
Fall and winter is a time to watch your watering schedule as your plants will be using less water and growing more slowly with reduced temperatures. In conjunction with this slowing down, you will want to reduce your fertilizing. Instead of a twice a week watering schedule, you may need to water only every 10 days. One of the moisture meters available can be very helpful in determining whether you need to water, or use the “pick up the pot” method to see if the plants are dry. Continue with a every-other-watering fertilizing.

Consider additional lighting
Windowsill growers in the northern latitudes should monitor how many hours of light your orchids are getting and if it is under about 10 hours, consider adding lighting fixtures to extend the hours to encourage flowering.

Watch out for insect infestations
As the weather turns cooler, insects will find your orchid plants and take up residency. When you bring in plants that have lived outdoors, be sure to dunk them in a solution of 1 tablespoon of liquid dish soap or insecticidal soap in a gallon of water. It’s best of you can dunk them entirely to catch any bugs on the plant itself. Allow to drain thoroughly.

Try to give your orchids a cooler night
Many orchids need a 10 degree, or 21 degree Fahrenheit, drop in termperature at night in order to grow properly. For windowsill growers this is a real challenge, but in the fall when it is extremely important, Mother Nature provides a hand. If possible allow the cooler night time temperatures from outside cool your growing area. Be sure that freezing temperatures do not get to your plants or that your plant leaves are not touching cold glass.

Use bubble wrap on your glass
In order to keep your plants from getting frozen leaves, be sure to keep them from touching cold window panes during winter weather. One idea I have recently seen recommends using commercial bubble wrap to cover your windows as extra insulation as well as providing protection for leaves close to glass. Many growers in very cold climates even use this idea in their greenhouses to add insulation and save on heating costs.

Tester pots
If you have trouble determining when to water, put a “tester pot” with your orchids and use it to determine when the media in your pots is dry. A tester pot is a pot without any plant in it filled with the same media that you use with your plants. Water the pot at the same time you do your other plants. When you want to see if the plants need water simply dump out the tester pot and feel the media in the middle of the pot to see if it is still damp. When it’s dry, then you know to water.

Setting Up A Terrarium

Terrariums

Nov 032008

by Susan Taylor
Originally published in BellaOnline

Many orchid growers graduate from the windowsill to a terrarium in order to better control environmental conditions, especially humidity, for their plants. An old aquarium can be used for this purpose fairly easily. If it was a fresh water tank, all it needs is a good cleaning with soap and water and an overnight soak in a bleach solution to kill any algae left in crevices. If it was a salt water tank, you will need to fill the tank with water and let it soak for several days, rinse and soak again, in order to make sure that all salt residues have been removed.

Although it is not very natural looking, most experts recommend using egg shell crate (material used for fluorescent light covering available at most hardware stores). This material is approximately ½ inch or 2 centimeters high with openings in squares of approximately ¼ inch or 1 centimeter. The effect when this is used as the substrate is then to keep all materials from the bottom of the terrarium while holding water and allowing it to evaporate up through the spaces.

You will want to choose props much like those used in a fish tank in order to make the whole thing look natural. Drift wood, rocks, cork are all good choices. Be sure that you clean and sterilize anything that you bring in from the wild. Materials purchased from pet stores are probably already sterile and will not need to be treated. Place your props, the largest in the background and smallest in the front before you put in your plants.

Plants should be chosen carefully for size and the larger plants can be placed in the back or growing up cork. Small plants such as Masdevallia, Pleurothallis and the smaller Paph species are good choices. Jewel orchids should always be considered since their foliage is always interesting when nothing else is blooming. Choose contrasting leaf colors for the best effect. Ferns make very good companion plants and will add a pleasing texture change to the scene.

Place your plants still in their pots and then add sphagnum moss around the plants and cover the egg crate so that it no longer shows. When assembled like this repotting is very simple – just take out the plant and pot, put in new media and then replace. Some orchids will tend to grow into their environment and should not need repotting if they have acclimated such as growing on a cork backdrop.

Maintaining An Orchid Terrarium

Terrariums

Nov 022008

by Susan Taylor
Originally published in BellaOnline

Once you have your terrarium set up for your orchids maintaining happy and healthy plants is easy if you give them all the elements of their environment they need.

Depending upon the type of plants you have chosen for your terrarium, you will need to provide adequate light. It is important when you set it up to choose plants which require like temperatures and light for best growth. In addition, it is good to try to group your plants by their light requirements throughout the year. Many epiphytes come from equatorial areas which receive equal amounts of light year round with little change from summer to winter. Your lighting requirements are fairly straightforward in this case: 11 to 12 hours of light. If, however, you have plants such as Cattleyas or other light sensitive plants, you will have to follow a spring, summer, fall and winter schedule. In general, spring and fall should require approximately 12-13 hours of light; summer approximately 15-16 hours and winter approximately 10-11 hours.

Air circulation is a critical factor in maintaining a terrarium. If you do not keep the air moving, you run the risk of encouraging pathogens such as molds which will quickly kill your plants. If you have set up your own aquarium, small computer fans will provide enough circulation to keep your plants happy. If you’re lucky enough to have invested in a professional Wardian case or terrarium, then the fans should already be included. You should also have a vent of some sort to allow warmer air to be moved out of the environment and fresh air in.

Temperature is another area which requires control in a terrarium. Artificial lighting causes heat which can quickly rise in the enclosed environment. A minimum/maximum thermometer which also records humidity is an ideal instrument. You will want to keep the temperature in the 75 degree Fahrenheit, or 24 Centigrade, range for cool growers and 85 degrees Fahrenheit, or 30 Centigrade, for intermediate growers. One great challenge for you will be to lower temperatures enough at night to get the diurnal drop that many orchids need at night. Turning off the lights will provide a relief from the heat they produce, but venting out that heat is the only way to really make a difference. Ideally, you will want a 10 degree Fahrenheit, or 5 Centigrade, drop at night. In reality, this is very difficult to achieve. I’ve even heard of people who put ice cubes in their terrariums at night in order to force this to happen, with mixed results from their efforts.

Growing Orchids In A Terrarium

Terrariums

Nov 012008

by Susan Taylor
Originally published in BellaOnline

A decorative idea for growing orchids in the home is the use of a terrarium, conservatory or Wardian Case. The concept behind the use of these items is that you create a mini-greenhouse inside to grow plants. They come in all sizes, colors and shapes to suit almost any décor. It is important to understand what will and will not work for orchids in this type of environment. The major thing to remember is that we are trying to replicate the growing conditions for the orchids we are putting in the chamber. Thus, high humidity, good air circulation and adequate lighting are required.

Terrariums by definition are self-contained ecosystems designed to live without disturbance for a year or more. The water in the container is constantly re-circulated by evaporating and dripping back into the soil or growing medium. Most orchids will not survive well in this kind of an environment because they need more air circulation or they will rot.

A Conservatory or Wardian Case is actually a mini-greenhouse with air vents, perhaps fans, lights, everything necessary to grow indoors. There are any number of combinations that can be used, depending upon your needs. The Orchidarium site has the most complete information I’ve seen, including what accessories are available. If you are considering building your own there are several really good articles available. The Do It Yourself Wardian Case article by Prem Subrahmanyam published in the Tallahassee Orchid Society Newsletter is extremely helpful and detailed.

In corresponding with several people who have successfully grown orchids in enclosed gardens, the primary comments were that it is necessary to have fans going 24/7, keep an opening to allow in fresh air, and to choose orchids which prefer high humidity, have lower light requirements and like the warmer end of the growing spectrum. It is extremely difficult to provide cool temperatures in enclosed spaces while using artificial lighting. One lady even mentioned trying to reduce evening temperatures by putting ice in the bottom of the enclosure, but found that that didn’t work adequately. And, most importantly do not have pots or plants sitting in water!

It is important to have automated controls on a Wardian Case because it doesn’t take much to cause conditions that will kill your plants. In order to keep the humidity up while the lights are on, misters are recommended. It is recommended that lights be used for 12-14 per day. Recommended orchids mentioned were Pleurothallids although Masdevallias don’t seem to like it as much as the Restrepias and mini-Dendrobiums.

One thing that I didn’t hear much about, but I would recommend is that you try mounted plants in a Wardian Case, especially if you are looking for a decorative display. Mounted plants need higher humidity to allow their roots to gather water than those in pots.

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