Water Culture


Water culture is something we've been experimenting with since Nov. '95.
The idea is simple. Culturing Orchids in no media except for water. The
water is present all the time. For those wanting to experiment with this
method of Orchid culture, we're presenting a few guidelines to help you.

Container

The container we prefer most is glass though we've even used rubbermaid containers with as good a success as with glass. The container needs to be deep enough to accomodate a large root system and the rim of the container should support the bottom leaves of the plant if possible. For pseudobulbous plants, a stake can be tied to the plant which will support it in the container.

Starting Out

Once you've selected which plants(s) you want to grow and the containers you want to grow them in, consider these basics: (1) Always use tepid water when initially filling or replacing the water in your containers. "Tepid" has no discernable temperature. It will feel neither warm nor cold. (2) Fertilizer strength and type should be the same as for potted plants. We keep fertilizer in the water at all times. (3) Water changes should be done weekly with daily additions if needed. Do not allow the water level to drop below the top of the roots for any length of time. So long as the water level is correct, there is virtually no risk of bacterial or fungal infections. Do not remove the algae growth from either the roots or the inside of the container. It's our feeling that it assists with gas exchange within what is basically a stagnant body of water. At the end of each week just dump the water and replace. (4) Temperature and light is exactly the same for water cultured plants as it would be if the plants were potted. In other words, follow the same cultural guidelines for the hybrid or species you're growing. Bear in mind that the water will quickly reach room temperature. A cold room will stunt the growth of the plant. A hot room will also stunt the growth of the plant. 65-85 degrees should be the outside ranges of the room with the max in the 80-85 degree range for intermediate growing Orchids. (5) "Repotting" is basically not needed until the root system has so overwhelmed the container that getting the plant out of the container would cause damage doing so. The roots in these containers will not rot and only rarely die so expect to see more roots than you're used to seeing. (6) Miscellaneous thoughts: We have yet to have a plant die in our own experiments. Some plants do seem easier than others though. Phrags especially seem fond of the method, while Phals, though growing nicely, seem somewhat slower than pot culture. Cattleyas, Catasetums, Dens, Mormodes, Oncidiums, Paphs, Zygos ALL do well. Bear in mind that plants just won't be suitable for this method if they need a rest period. Give it a try, have fun, and be sure and let us know how things work out! If you have any specific questions, feel free to email me. Below are comments by Robert Lin regarding the differences in water, aerial and media roots. Used with his permission. Date: Sat, 23 May 1998 19:53:27 -0400 From: Robert Lin To: venger@vengers.com Subject: Re: Roots! You have asked a very difficult question to answer without writing a small book. To give you a generic short answer for others to understand, I must first qualify my statement before I make it. All of my information is based on other people's publications. My answer is based on what I've read and the answer is not exclusively true for all orchids as some have very different root structures based on their unique development and adaptive needs. First, orchid roots function to uptake water and nutrients, preserve water loss during drought conditions, and also allows the exchange of gases to regulate life cycles. Root structures (i.e., cellular shapes, sizes, types, and the number of cells from the cortex to the velamen) will vary from species to species and maybe from plant to plant depending on what and where it is growing. For this and many other reasons, orchids (and other plants) are highly adaptive to changing/varying environments. Many people have reported that orchid roots develop differently depending on the surface it comes in contact with as it is growing. Roots can grow fully exposed dangling in the air, in contact partially on a surface (e.g., bark), and/or growing in a soil medium. When an aerial root touches a surface, the portion that comes in contact with the surface will adapt differently so that the cellular function is optimized for the plant survival. For example, the area that contacts a piece of bark will often develop roots hairs on the bottom side, together with smaller velamen cells and thin walled passage cells. This will help an orchid cling to the bark and allow better transfer of water and air on the bottom side as it grows attached. On the exposed side, passage cells become more lignified or suberized for protection and reduces water loss in the air. Roots growing in soil can develop a modified velamen layer but do not always do so like roots exposed to to the air. If roots grow into water, they will adapt to regulate water passage with specialized cell development for a water environment. Established aerial roots placed into water (as compared to new roots that grow in water) usually survive and can adapt because aerial roots have outer cells that are structured to not allow water freely into the plant (but can still regulate gas exchange). This allows time (maybe 3-6 months) for an orchid to readapt and grow water roots in the new water environment. Some aerial roots will rot soon after being placed into water but this can be attributed to physical damage that occurred before being placed in water. A crack along any part of the root will allow water (and therefore fungus/bacteria) into the unprotected center of the root and rot occurs. Some aerial roots just can not adapt to water conditions and die off, but hopefully new water roots have developed by that time. In general, water roots, aerial roots (attached and unattached), and soil roots are different because the roots have developed differently to optimize and regulate their growing condition. Orchid roots adapt by developing specialize cells based on the surface it touches, so each root can be structurally and functionally different from one another. An orchid will try to adapt physically, chemically, and biologically to an enviroment to ultimately produce offsprings.

See a photo of a water cultured Orchid



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Colorado Springs, CO 80906
Web http://www.vengers.com/
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