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EARLY SPRING
CULTURE

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 Now everyone should be enjoying the fruits of their growing success - plenty of flowers. If you do not have plenty of flowers appearing, now is the time to review your culture over the last year, with the objective of improving results next year.
  •  If your plants have not flowered this year, but should have flowered, now is the time to review your culture for the year to ascertain the reasons for this unhappy state. It may be that the growths did not grow large enough (watering, growing mix unsuitable, insufficient fertilisers) or shade and light levels may be unsatisfactory. Their growth may have been affected by disease, especially of the roots, insect damage, etc. Refer Flower bud initiation for a discussion on this aspect.
  • A major reason for non flowering of cymbidium orchids is keeping them too warm over the summer months. They should be kept outside under dappled light where they receive plenty of sun and cool fresh air.

  • If you do have plants in flower, you must eventually remove the spikes for the plants. Do not cut the spikes from different plants with the same knife or scissors. It is better to break the stems. This prevents the spread of disease, especially viruses.

  • We are now entering the period for repotting. Many different potting mixes are available and suitable. A good mix must be porous enough to permit the ready passage of water, but at the same time must have the ability to retain moisture. It must not break down too quickly, and must not pack at the bottom of the pot too readily. It must also have a suitable pH, and be of a reasonable cost. Locally the use of pine bark mixes usually meet these requirements, although in your location other materials may be suitable. Talk to a local grower to ascertain what is best in your location if you are uncertain.

  • In most areas commercial mixes are available, although most growers find the removal of the finer material desirable. The pH is usually corrected by the addition of lime, plus a solid general fertiliser is added - say at the rate of atablespoon per 10 liters of mix. Powdered fertilisers (phosphate, potash) are added, although the slow release products such as Osmocote and Magamp may be more convenient. Bark mixes require a higher level of nitrogen fertiliser as this is utilised by the mix micro-organisms during normal organic decomposition.

  • Potting mixes break down through normal bacterial and fungal activity once it is wet, as part of normal organic decomposition. For this reason, most mixes have limited effective life - usually only 2 to 3 years. Washing mixes, removing the dust and fine material can assist in prolonging its life. Bark mixes should be soaked for some days to wet it completely before use, then allowed to drain as a wet mix cannot flow around the roots during repotting.

  • The ;process of repotting is described on a separate page - repotting and that material should be referred to.

  • Repotting usually is completed just after flowering. The ideal time is just as new root activity commences in the spring after the usual winter dormancy or period of reduced activity. New growth is indicated by the green tips to the roots. The aim is to get the plant re-established as fast as possible, so a strong growth is initiated and reached maximum size at maturity to ensure maximum flowering next year.

  • After repotting, plants should be kept more shaded and somewhat dryer than usual. Misting the foliage only for 2 to 3 weeks may be all that is required. Normal watering can be commenced once root activity is evident. Some growers return the plants immediately to the normal watering regime, but generally re-establishment appears to be better if the procedure indicated above is followed

  • Do not forget to re-label all repotted plants, and divisions with their correct name and date of repotting. A plant without its correct name looses much of its value.

  • Do not throw the old back bulbs away that you have removed during repotting. Bury them in the usual mix in as small a pot as possible. The majority will eventually produce a new growth. Pot into larger pots as required. Such identical replications of the original plant should themselves flower in 3 to 5 years.  This is a good way to obtain more plants which can be sold, exchanged or given away. Remember to treat the cut rhizome with a suitable fungicide (flowers of sulphur is a cheap and effective material) or dry for several days before repotting to prevent the entry of disease. The use of bottom heat will increase growth, reducing the period to flowering by 1 to 2 years. Old pseudobulbs can also be started by being placed in a plastic bad in damp - not wet - sphagnum moss and placed in a shaded but warm position. Once roots are seen, repot as normal.

  • With the warmer temperatures, increased ventilation of the glasshouse will be required, especially on the odd sunny hot day possible towards the end of the month, when glasshouse temperatures can rapidly rise to very high levels. With warmer days, and increased plant growth, more frequent watering will be indicated. Adjust frequency to the individual needs of your plants.

  • For plants not repotted,the application of additional base fertiliser will be appropriate, and some lime or dolomite will help sweeten up a mix which may have soured somewhat during the winter (1 tablespoon of lime per 10 litre bucket). Cymbidiums in particular are gross fedders, and supplementary feeding - a little often - is appropriate. At this time of the year when maximum vegetative growth is the aim, products high in nitrogen are desirable. A dry mix of nitrogen, phosphate and potash can be formulated, or one of the proprietary slow release products may be appropriate.

 

 

 


Site established 9th May 1998