Rhododendrons: Slow growth, patience, three years in the making

Discussion in 'Ericaceae (rhododendrons, arbutus, etc.)' started by joZ, May 26, 2008.

  1. joZ

    joZ Active Member

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    The picture shows an apparently rare type of rhododendron given to us from a family member on Vancouver Island. After three years, this is as big as it has grown. Last year we recently transplanted it from pot to the ground, and then transplanted it again to a sunnier location... where it sits now. It has only just started to grow. We thought it was dying after it's leaves turned rusty red and fell off. But, to our surprise, it is doing more now than it ever has !! Can someone comment on the growing stages of this rhody? Where it is now and what I can expect ,or not? It is so slow, I am thinking of moving it into a pot again... as it is taking up valuable soil in a small garden. I am trying to be patient... but as a newby gardener, I am biting my lip with this one.
     

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  2. Ron B

    Ron B Paragon of Plants 10 Years

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    You are not seeing much from it because it is stuggling. Looks like you have it planted too deeply in unsuitably heavy mineral soil, in a location where hot sun beats on the foliage and roots. The discoloring and premature dropping of the leaves is a malfunction, probably indicating something like an unsuitably alkaline potting soil or fertilizer, or use of fertilizer that is too strong. Too much hot sun may also destroy the foliage of kinds of rhododendrons (and other shrubs) that require pretty much full shade to do well. Although not always the case there is a tendency for the leaf size to indicate sun tolerance, the requirement for shade increasing with the size of the leaf.

    In general rhododendrons require a cool well-aerated acidic soil with ample moisture during the growing season. Although it varies somewhat as there are many species spread over a large area the common natural situation for wild species is a sandy, peaty or otherwise well-aerated or non-compacted soil in a cloudy and rainy climate and comparatively low in nutrients. Often in the wettest areas many will find their niches primarily in moss-covered organic detritus accumulated on the branches of larger trees, rock slides and cliff faces.

    In cultivation poor growth and even decline is often due to water molds attacking their fine delicate roots (and even their stems, above the ground) when the plants are planted in hot and damp soil or pots are splashed, watered with or left sitting in infested water. Honey fungus (Armillaria) also seems to be common on them in this region, many apparently tough old specimens of garden hybrid rhododendrons found to have the telltale rhizomorphs clinging to the bases of their trunks.
     
  3. joZ

    joZ Active Member

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    Many thanks for the detailed reply. Ok... then... I should then replant in an area where it is less compacted soil, and more moist. I have a more bright, fuller shade location... but when it was in that kind of location before, it didn't grow at all. So, that is why I am a bit confused. I guess the only thing I can do it continue to try different, better locations and see what happens. Should I wait until after it goes through this "growth spurt"? Or should I pull it up right away and give it the happy soil that it would prefer?
     
  4. joclyn

    joclyn Rising Contributor

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    it will do best if it's in a spot where it is shaded in the heat of the afternoon sun...morning sun for an hour or so is okay.

    they do best in soil that has a high acidity.

    if it's in a spot where it's getting too much sun, then you will need to move it again.

    moving it repeatedly is part of the problem. any plant will go through a bit of an adjustment period after it's transplanted...sometimes it takes 2 and even 3 seasons before the plant is really back on it's feet.

    to assist with getting it established, water at the roots every day or two for the first couple of weeks. ALSO water a couple of inches outward - you want the roots to reach out to the moisture. after the first couple of weeks, only water in a ring a few inches outward from the plant...water the roots directly once a week. you really want those roots to spread out, so, putting the water 'just' within reach is the way to accomplish that.

    move it now, so it has plenty of time over the season to get those roots going. then, next spring, feed it with a product specifically for rhododendron/azalea. feeding it now will only stress it more.
     
  5. joZ

    joZ Active Member

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    Great advice. Ok then...
    To Pot or not to Pot... that is the final question... At this stage, when one doesn't even know if the poor thing is gonna make it... and the other spots in my garden are either full shade but relatively bright (I have an purple azalea, a 15 foot camelia, and a 12 foot aucuba that love it there) or full sun (which it won't like) then is a pot the next best thing?
     
  6. Ron B

    Ron B Paragon of Plants 10 Years

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    Azaleas are also rhododendrons and have the same soil requirements, although some will grow in hotter climates (and soils) than any other rhododendrons you are not located where such would be the case - the one spot suiting the azalea indicates your rhododendron is likely to like it there also - assuming it isn't infested with water molds or have another lingering severe complaint perhaps likely to prevent it from bouncing back even when moved to a better spot.
     

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