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Rhododendron help needed, please

earthlydelights
17 years ago

Hi, while out doing some clean-up, I noticed that two of my plants have absolutely no buds on them while others are just covered in them. Do the non-budding ones mean there will be no flowers this year? What would cause this to happen?

Thanks

Maryanne

Comment (1)

  • rhodyman
    17 years ago

    Failure to set flower buds may be a sign of too much health and vigor in a plant. One solution my be to prune the roots by cutting around the plant with a spade or moving the plant. This will check foliage growth and encourage production of flower buds. Application of nitrogen rich fertilizers are the main cause of vigor which suppresses flower bud production. Deadheading flowers as soon as they wilt can promote flower bud production. Too much shade, a cool wet summer, or inadequate phosphorus or potassium in the soil may also suppress flower bud production. There are a number of other reasons for a lack of flowers. The effect of each variable depends upon the variety of the plant. The effects include:

    * Pruning. The buds are formed in late summer and early fall so pruning then or later is not advisable since it will remove flower buds. New leaf buds will form in the spring, but new flower buds won't form until the next year.

    * Variety. Some plants will never bloom. Some rhododendrons that come from the seed of a hybrid plant will look good but will never produce flowers or will produce very poor flowers. To come true to the parent plant, a hybrid may be propagated by cuttings or tissue culture but not from seed. A good hybrid seedling only comes about once in a while. For that reason it is important to know that you are getting a good named variety or a good species.

    * Fertilizing. Nitrogen promotes leaf and branch growth and discourages flower bud production. It can also force late season growth that gets killed or stunted by frost damage. Phosphorus promotes flower bud production and hardiness. Potassium is necessary for well being.

    * Weather. Cold weather can kill flower buds. Usually you see the brown buds in the spring. Cold spells in the fall or spring can damage buds that are not hardened off. Bud blast (blooming in fall or winter) uses up good buds which are then not available at the normal blooming time.

    * Age. Most rhododendrons take 2 to 3 years to bloom from a rooted cutting unless forced. Some take longer and some bloom sooner. From seeds the plant may take 1 or 2 additional years.

    * Sun & Shade. Some rhododendrons need full sun to bloom and others can take fairly dense shade. In general, the more sun the more flower buds but also the greater exposure to damage from desiccation in summer or winter. More shade produces tall spindly foliage and less flowers.

    * Inspection. You can usually tell if the plant has ever bloomed. A rhododendron that has bloomed will have the seed pods on it unless it has been dead-headed. If dead-headed too late after blooming, new flower buds can be damaged.

    There are many other cultural variables that influence the plant's health and hence, its ability to produce flowers.

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