Question
QUESTION: Hi Wayne King,
I'd like to ask you one more question. How to fertilize while flowering plant( or mature plant) & new plantlets are in the same pot? Just use 20-20-20 only or 10-40-15 only or use both alternatively on weekly basis or spray flowering plant(mature) with 10-40-15 while using 20-20-20 for plantlets at the same time or how? Because I have dendros which mix new plantlets & flowering spike.

Can I spray fertilizer or water directly to flower spike and blubs?

Your kind response is greatly appreciated.
Thanks in advance,

Nwe Lay

ANSWER: Dendrobiums have different requirements than your oncidium (I assume you also have dendrobiums because of your reference to "dendros").  If you have a dendrobium in spike as well as plantlets suggests that you did not provide a rest period for the dendrobium.  Usually, dendrobiums have a growth, rest, flowering cycle.  When the rest period is not provided by continuing the watering and feedings when it should be resting, new growth can start. There is no need for watering or feeding a dendrobium while flowering.  In fact, that will start the new growth instead of going into a resting period.  A continuously growing dendrobium (ie provided no rest period) will result in smaller and smaller growths with eventual loss of the plant.  As long as you have the new plantlets (from the base of the old growth), feed with 20-20-20 until they are mature. Then, stop wat6ering and feeding and allow the plant to rest with occassional misting only to maintain firm canes. It may rest for several months.  It will tell you when to resume watering and feeding by coming out of the rest period with new growth.

I recommend the same for the oncidium. When all oncidium growths are mature, rest it until its normal flowering season and then begin with the 10=40-15.  Always water and feed into the pot.  In misting the plant, do it early in the day to permit all flower and plant surfaces to dry by nghtfall.  

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QUESTION: Thanks a lot for your answer.

It is Dendrobium Phalaenopsis.  So, Does the resting period apply to them? You mentioned that during flowering no need to fertilize for dendro. So, 10-40-15 is no need for dendro, isn't it? They only need 20-20-20 while in growth stage,isn't it?

In gereral, which orchids need resting period?

Your answer is invaluable to me.

Thanks in advance,
Nwe Lay

ANSWER: Yes, the resting period applies to all dendrobimsa. During rest, dendrobium phalaenopsis may retain most of their leaves, so it is important to mist early in the day during rest rather than water or feed. You need not mist every day but at least twice a week.  Remember that during rest, they don't need as much light or heat because they are not growing.  When new growth starts, increase light, start to water/feed (20-20=20 or higher nitrogen eg 30-10-10).  Dendrobiums and all orchids can benefit from 10-40-15 after (or near) maturation of the new growth.

Orchids not benefitting from a rest period are principally the lady slippers and other terrestrials and phalaenopsis. Orchids that have canes or pseudobulbs have a rest period. With the latter, do not include root growth (visible from the surface) as part of the rest period.  Some orchids finish their vegetative growth before sending out new roots. If you see new roots emerging from the base of the plant, wait until these have finished before entering the resst period.

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QUESTION: Thank you so much for your reply.

I live in Singapore. True to its Southeast Asian location, Singapore is characterised by a hot and humid climate. Located just 1 degree north of the equator, it quite naturally enjoys a tropical/equatorial climate. The island does not have clear-cut seasons like summer, spring, autumn and winter. The weather is warm and humid all year round with the temperature almost never dropping below 20癈 (68癋), even at night, and usually climbing to 30癈 (86癋) during the day. Recent times, it even reached till 35癈.November and December is the rainy season. April is the warmest month, January is the coolest month. Abundant rainfall.

I have Vanda,Dendro,Oncidium, Cattelya & Phalaenopsis orchids. Which orchid do well in such climate according to your experience?

I would like to seek your advice for general orchid care tips for my orchids growing in this climate.

Your help is greatly appreciated.
Nwe Lay

Answer
You live in a climate in which all of your orchids should thrive. In general, keep your open potting mix fairly open so there is good drainage and air movement thorugh the potting mix.  Use a high nitrogen food during growth and a balanced fertilizer most of the rest of the time. All of the orchids except phalaenopsis have resting periods so try to honor that.  Switch to high phosphorous when approaching the bloom season.  Be careful of the light levels.  Phalaenospis prefer the lowest light level of those mentioned, otherwise use maximum light short of leaf burn.