Your "Peace Lily" (Spathiphyllum) or Anthurium won't bloom? This may be why!

Discussion in 'Araceae' started by photopro, Dec 4, 2009.

  1. photopro

    photopro Well-Known Member

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    Siloam Springs, AR, USA
    I posted this recently in response to a question asking why a "Peace Lily" isn't blooming but thought some that love to grow Anthurium and Spathiphyllum hybrid might want to know the answer as well.

    There is almost certainly a chemical reason your "Peace Lily" or Anthurium is either hesitant or not blooming at all. The next time you buy a beautiful Anthurium or Spathiphyllum at a discount store or nursery and find it begins to produce either no blooms or odd shaped leaves and spathes once you get it home there is a reason. The specimen has very likely been fed gibberellic acid since it was nearing sexual maturity to force it to mature and bloom early.

    Anthurium, Philodendron and Spathiphyllum species ("Peace Lily") are aroids. The genus name is Spathiphyllum and there are many species found in the tropical Americas. Anthurium species are also only found only in the Neotropical world (the tropical Americas). Although there are over 1000 species not all have been published to science just yet. Many are currently under study by aroid botanists such as Dr. Thomas B. Croat of the Missouri Botanical Garden in St. Louis. Tom is recognized as the world's leading authority in several genera of Araceae (aroids). Now for those of you in SE Asia or the tropical Pacific that will be saying you see Anthurium and Philodendron species in your area of the world..........all were imported! They do not live outside Central America, South America and the Caribbean naturally. There are a few natural species of Spathiphyllum found in SE Asia.

    Aroids produce their inflorescences depending on the time of year and season nature has predetermined. Some species produce a spathe and spadix only during the dry or wet season in their natural habitat while others freely produce an inflorescence any time of the year. Anthurium normally bloom only once per year but fortunately Spathiphyllum and the common Anthurium hybrids often bloom year round. If you want to know more about how aroids reproduce you can find information here: and artificial pollination in aroids.html

    By the way, the often colorful spathe (normally white in Spathiphyllum species) is not a flower but is instead an inflorescence or group of flowers. The flowers are near microscopic and can be found along the spadix at the center of the inflorescence. The spathe is simply a modified leaf. In the case of aroids the word "bloom" refers to the tiny male and female flowers on the spadix and not the spathe. These very tiny flowers are visible for only a few days immediately after the inflorescence first opens.

    These plants grow naturally in bright indirect light (not a dark corner), Anthurium species are found up in trees much more frequently than in the soil but all can be trained to live in soil. Spathiphyllum species normally live in water and are terrestrial species!! My friend aroid botanist Tom Croat who knows more about aroids than any living human being calls them "water hogs".

    Although many folks recommend lower light and water for both Anthurium and Spathiphyllum the claim Peace Lilies should be kept in a dark area of a home and rarely watered do not understand the plants as they grow and survive in the wild. Both Anthurium and Spathiphyllum must be watered regularly to keep them blooming and they need bright light, just not direct sunlight. They will survive in dim light but that is all they will do. Just survive!

    However, both Anthurium and Spathiphyllum must have fast draining soil and not soggy mud in their pot! You must mix peat moss, orchid bark, Perlite, and cut up pieces of sphagnum moss into their soil to keep them happy and blooming.

    Now, here's the reason your plant is likely not blooming.

    The commercial growers that produce these plants use a chemical known as gibberellic acid often sold as GA3 to induce the plants to produce an inflorescences in order to make them more attractive at the time a buyer sees one in the store. A few people on other forums actively promote the use of GA3 for aroids but the long term use can be harmful to the plant and may eventually stop the plant from reproducing naturally. As a result, if you are a collector and value your plants, consider the use of the product with extreme caution!

    Gibberellic acid is a natural plant hormone and is used in agriculture to stimulate both cell division and cell elongation that affects the leaves as well as stems of a plant. The stem is the base or central axis of the plant and not the stalk that supports any leaf blade. The support for a leaf is the petiole and there is a major difference in a "stem" and a "petiole". This explains the difference and why the term "stem" should not be used for the stalk that supports any leaf: is a stem. What is a petiole.html

    The continued use of GA3 in agriculture eventually affects fruit development. Since the fruit of an aroid is produced on the spadix gibberellic acid thus speeds up the the production of inflorescences.

    The big problem with GA3 is the plants become "addicted" to the chemical and if the poor grower that buys the plant does not understand this as well as the fact it will take years for the plant to outgrow the addiction they will soon be disappointed. In most cases it can take one to three years for the plant to out grow the "chemical addiction".

    Plants produced for commercial sales are almost always created in a chemical "soup" through tissue culture (cloning) and not grown from seed. Gibberellic acid is used commercially to make all the tissue cultured plants in one group bloom at the same time.

    Through repeated use these large growers force the natural growth of a spathe and spadix regardless of season. They have calculated the quantity to be used and know how much gibberellic acid to apply to any particular species but these formulations are often guarded secrets.

    An article by Dr. Paul Resslar on the production of an inflorescence of Caladium humboldtii can be found in the IAS journal Aroideana, volume 31, where he discusses the amounts and methods of application used in his research. Aroideana is the journal of the International Aroid Society and out of print copies can be ordered at

    Deformities caused by the use of GA3

    In Dr. Resslar's experience the chemical also can result in deformities. Deformity is considered a minor problem in commercial aroid production including double spathes, spadices with strange shapes, malformed leaves and other side effects. One of the side effects may well be the plant becomes dependent on the chemical to induce the production of an inflorescence and flowers. A presentation by aroid enthusiast Ted Held at the 2008 International Aroid Show in Miami pointed out these exact problems.

    However, these deformities are much more common than most home growers realize. I recently talked to one of the largest growers of tissue cultured Anthurium and Alocasia in South Florida and was told they commonly throw away large quantities of plants since both the leaves and inflorescences are malformed.

    Discussions on these effects can be found on the International Aroid Society forum Aroid l by searching the archives of the forum on the internet.

    Some of the world's best aroid botanists and experts do not find the use of the chemical to be wise. As a result, the use of gibberellic acid by aroid collectors with no experience in chemical use is not advisable and should be used with caution even though it will work. The use is primarily not advised since collectors have no way of knowing how much of the chemical to apply to any particular specimen based on species or size. But there are other problems.

    The instructions on some of the containers of GA3 say to apply the chemical near the base of the plant but it also says boldly not to allow the chemical to come in contact with the roots! Some material indicates this may not be accurate but the warning can be found on sometimes on the product itself. Since the roots are at the base of the plant is is obvious the chemical can be dangerous to your plants. Other potential problems stated in papers on the commercial use of GA3 indicate the chemical will increase plant height, slightly reduce leaf width, and soften stems during periods of low light during shorter days. Still, commercial growers love the product because it increases their production and profit.

    Without the constant use of the hormone to induce inflorescence production the specimen cannot get its "fix" and as a result may rarely bloom again. It has been "hooked" on the chemical! Collectors should consider using the product with extreme caution.

    You must give the plants regular doses of diluted fertilizer to keep them producing an inflorescence but don't over fertilize and use only distilled water, not tap water. In all cases these plants need to be watered at least two or three times per week, just make sure they have fast draining soil. Keep them in fast draining soil (not the stuff you buy in the store) near a bright window and not in deep shade.

    More information on Anthurium species and how they need to be grown can be read here: or Growing Anthurium species.html

    This link may also be useful if you are afraid to water a "Peace Lily":

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    Last edited: Dec 13, 2009
  2. photopro

    photopro Well-Known Member

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    Siloam Springs, AR, USA
    I failed to state the best way to fertilize these plants. There are two good options.

    The first is to use only rain water, RO (reverse osmosis) or distilled water and mix a dilute fertilizer in every time you water. Approximately 10% of the manufacturer's recommended does will keep the plant happy. If that is a problem then use the pellet fertilizers of which I prefer Osmocote 14-14-14. Similar commercial blends are used by many commercial growers.

    Do not used deionized water (DI) since it is too purified for the plant and tap water may contain harmful minerals.

    Keep the soil evenly moist at all times.

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