Rubber plant help :)

Discussion in 'Indoor and Greenhouse Plants' started by brownthumbs, Oct 2, 2007.

  1. brownthumbs

    brownthumbs Member

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    Hi Everyone
    I have a rubber plant (I believe) that isn't doing very well.
    Just after I purchased it the leaves started curling in on themselves, turning brown and falling off. I also noticed when I watered it that the water just ran right through the pot and poured out of the bottom. I realized from reading various posts here that it was probably root bound and replanted it in a larger pot. After repotting it, the leaves reopened and new ones opened and it seemed to be doing great for about 6 mths. Now again the leaves are beginning to slowly curl up and when I water it the water seems to run right through. But the pot seems to be big enough for the plant size. I'm wondering if I need to somehow "trim" the roots so that it's not such a big root system for the size of plant that it is. Or should I repot it in yet a bigger pot?
    Any help would be greatly appreciated! This is the first dying plant I've ever owned that I was able to save and I would like to do it again!
     
  2. photopro

    photopro Well-Known Member

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    You didn't say how you are growing this specimen, and that is important.

    The water running through is fine. These plants don't like wet roots. They do enjoy fast draining soil so you should water often enough to keep it damp. But I've got a suspicion as to why it is not doing well.

    If you were to visit any South Florida nursery that grows Ficus sp. (rubber trees are ficus) you'd see they are all growing in direct sunlight. These trees are not grown in shade and can grow to well over 15 meters in height. But then they are shipped off to nurseries as "house plants". As soon as the plant is shocked by the withdrawal from the sun it will begin to drop the leaves. Nurseries will rarely tell you why.

    Grower after countless grower has lost this specimen by trying to force it to grow in dim light. The only way you might have success is put it in the brightest place possible. I'm going to give you a set of simple tests to try to find out if you have enough light:

    If you have access to an older camera, here is a simple method of determining if the tree is receiving adequate light.

    First, a short photography lesson. Light is measured by a professional photographer in f/stops. The higher the number, the brighter the light. So you are looking for a high number, not a low one. The meters in cameras are known as reflectance meters. They are designed to measure the amount of light reflected from a subject. As a result, you must use a card that is a medium gray color to gather a correct f/stop number. Very bright colors and/or very dark colors will give a false number.

    You'll need a camera that has a built in light meter. Some digital cameras can be used for this test, but you'll need to check your instruction book. Set the camera to ASA 100 (that is important so you may need to find the camera book to learn how to do that). It is also sometimes called ISO.

    Second, set the shutter speed of the camera to 1/60th of a second. Again, this is important so find that book.

    Third, get a piece of cardboard that is gray in color. The cardboard that comes from the laundry in a shirt is perfect.

    Have a friend hold the card directly adjacent to the tree. If it is near a window, don't cheat. Put the card on the room side of the tree. Then aim your camera (set as instructed) at that cardboard. Get as close as you can. If it is out of focus, do not worry. You are only measuring the light, not taking a photo. Just don't create a shadow on the card.

    Once you've done all of this note the f/stop indicated by the camera. If you are outside it will read f/32 or f/22 in direct sunlight. Most ficus will love that. Indoors it will likely be a much lower number. If the number is not at least f/11 the ficus is not likely to receive enough light to survive well. Anything lower than f/8 and the ficus is almost certainly destined to die. At f/11 you can still see shadows on the ground. With f/8, there will be only a vague shadow.

    This is not terribly important if you aren't learning to take photos, but just as a reference, the sequence of full f/stops is f/32, f/22/ f/16/, f/11, f/8, f/5.6 and lower. An f/32 is very bright light but an f/22 is exactly 1/2 that amount of light. And each lower number is again a halving of the intensity of the light. So an f/8 is only 1/5th the amount of light as f/32.

    Its a simple test, easily done, and will quickly prove if you do or do not have adequate light to keep the tree healthy. But this will help keep your rubber alive and healthy.

    If you are growing in very bright light then we need to look at other causes.
     
  3. joclyn

    joclyn Rising Contributor

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    thanks, steve!! that's some very valuable info!!
     
  4. photopro

    photopro Well-Known Member

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    Since you've read some of my website you know I hate to see specimens die! I just try to find out the best ways to keep them healthy. In the case of ficus, I personally knew a grower north of Homestead who produced thousands of them each year for the trade. Every single one was grown in a field with direct sunlight. But every weekend I'd see his plants in a local garden store under a canopy.
     
  5. brownthumbs

    brownthumbs Member

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    Wow- thanks Steve. That is a whole lot of info! I'll get my cameras out and see if any of them measure light. Unfortunately it's in the brightest spot in the house pretty much so there's probably not much I can do if the light isn't high enough. It gets direct later afternoon light (say from about 2:00pm on...)
    I'll check it out though and let you know if it works!
     
  6. photopro

    photopro Well-Known Member

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    Hope this one works out for you. I've got two of them in my atrium and both barely hang on. One is very tall and scraggly (over 4 meters) but just barely makes it. The other will hardly grow. I knew when I planted them they would have a tough time but both were gifts from people who know I love tropical plants and I don't like to just kill any plant. But my atrium is designed for plants that prefer diffused light.

    Hope the plant survives for you. They do feed fairly heavily so I'd consider giving it a descent fertilizer, just don't offer more than the manufacturer recommends. And do keep the soil damp, just not soggy wet.
     

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