Question
QUESTION: Hi, I live in NW FL and my orchids love it outdoors in the summer. Now that it's winter I bring them in and put them in a sunny window.  They've been indoors for about 3-4 months now and my Dendrobium, which has several new growth stems(6) that will probably bloom this year has one new stem that has the two youngest leafs on the end of the stem turning yellow.  There are no insects or webs, the potting mix dries out between waterings, if anything I may not be watering enough except the rest of the stems are healthy, green and shiny.  Any suggestions?

Thanks

ANSWER: There are three possibilities that occur to me.  The first is that you did not allow the dendrobium to go into dormancy.  Most types of dendrobiums are best rested after their growths mature. If watered too much during this period of dormancy. They "think" it is spring and prematurely begin new growths. Over several growing seasons these new growths diminish in size.  Possibility #2 is that the plant is not strong enough to support the last and smallest growth. It is not uncommon, given the right conditions, for dendrobiums to try to put out new growths even when there is not enough energy to support these.  Possibility #3 is that overwatering has led to some root rot.

If the several new growths are as large or larger than last year's growth, then, I would not be concerned about the growth with the yellowing leaves.  You need be concerned only if the most recent growths are smaller than last years growth.  If that is the case, one or more of the possibilities mentioned above are likely.

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QUESTION: Please explain dormancy - I am new to growing orchids.  This plant bloomed last late winter (about this time) and was placed outdoors in a secluded, semi-shady spot where a sprinkler would water it.  I ignored it and didn't start fertilizing it until 2 to 3 months ago when I moved it indoors.  Would that time that it was outdoors constitute 'dormancy' or do I need to treat it differently?  Currently it gets a soaking once a month and once a week a 'very weak fertilizer' (about 1/2 cup) poured over the top which runs right thru to the tray under the pot and the tray is dry the next day when I go by.
Also, those yellow new leafs are weak,drooping.

Thanks

Answer
Barbara, the dormancy period is the period between flowering and the start of new growth.  In nature, this corresponds to a dry period when the plant is exposed mainly to mists to maintain turgor in the canes. When new growth starts, this signals the end of dormancy.  With the end of dormancy, regular watering and feeding can resume to support the new growth.  Also, this start of new growth is the time to repot so the new growth will have the most ideal conditions to do well. Dormancy often occurs during the winter months. Your watering and feeding schedule seems appropriate for a plant not in dormancy. As I mentioned, if your new growth is vigorous and, when mature, is as tall or taller then previous growths, then the plant seems to have come through dormancy fine. If the new growths are healthy, I would wait until after flowering to encourage dormancy by switching just to misting every other day.  It may also be too late to repot-- especially if the new growth is healthy.  Repot only when the plant comes out of dormancy and starts new growth (probably in the fall).  These plants love to be summered out and they like a lot of light.  Increase the outside light level gradually starting with a semishaded location.  

There are two overall types dendrobiums.  The warm growers have an erect flower spike usually originating near the top of the cane.  The other type, cool grower, has flowers which emerge directly along the cane.  The warm growers are the most common. Warm growers like temperatures 75-90 degrees F,  The cool growers do best at 40-70 degrees F.

Expect the the new yellow, drooping leaves to fall from the cane.  Don't concern yourself with those,but rather, with the overall health of the other new growths. In general, the time you bring your dendrobiums in from outside, after flowering, is the start of the dormancy period.  The light level is lowest then and misting should be started in the mornings.