Question
QUESTION: Hi,

I have two orchids that had flowers before, but they seem to have been dormant for some time and have only within the past few months started sprouting new leaves and roots. Spikes haven't been coming up in a while and it's mid spring!!

The first one is a phal that was at my parents' house and hasn't flowered in about 2 years. I took it back to my place which is warmer and has more light. I repotted it earlier this year and it's secure in it's moss medium. It has what looks like a new growth/plant coming out of the side of the main plant and one tiny root. When I bought the orchid for my parents the blossoms on this phal were plentiful, huge, pale yellow, slightly ruffled edges, and very unique looking. I feel like I'm following all the rules, but I don't see results.

The second orchid is a dendrobium, that had a few while blossoms when I purchased it, but they haven't come back. The stock they were on lost all it's leaves but the top two which are starting to weaken now. The plant has all together 3 stocks, the largest having the two top fading leaves, the second is smaller and seems to be drying up, and the third is a new stock (has grown to be roughly 4") with new green leaves that is growing each day. There are roots coming out of that stock, but the other stocks don't seem to have much of a purpose. What can I do to help this plant along and get it to flower?

-Theo

ANSWER: Theo, you have two entirely different types of orchids that require different growing conditions.  Let me first address the phalaenopsis. One of the most significant factors promoting flowering is light.  There should be enough light on the leaves so that your finger, when placed between the light source and the leaf, casts a distinct shadow on the leaf. Leaves that are dark green is an indication of light levels that are too low to promote flowering. Leaves should receive enough light to turn a lighter shade of green. Good growth is also necessary to promote good flowering.  Each new leaf should grow to be as large or larger than the previous leaf. Generally, use of moss as a growing medium should be avoided as it tends to compact over time.  This can resrict the flow of air to the roots and results in an uneven distribution of moisture in the root zone. These two factors can lead to root rot and this can affect the vigor of the plant and its ability to flower or a reduction in flower size and number.
I recommend that you repot the plant in a fir-bark based orchid potting mix. Be sure to wet the potting mix thoroughly as fir bark tend to repel water and needs to be soaked thoroughly to make it less water repellant.

Dendrobiums have growths called canes.  It is not unusual for older canes to lose their leaves.  Unlike phalaenopsis, dendrobiums have a distinct growth and rest period.  If they are watered when in their rest period, canes can rot and/or produce premature growth which becomes progressively smaller. When new growth ceases, provide water only through occassional misting. Old canes that are leafless, but firm, contribute to new growth and should not be cut off unless the cane has collapsed-- a sign a cane rot.  Canes should be firm.  Rotted canes should be cut off.  Old canes contain "eyes" at their base from which the new growth comes. The cane containing these eyes provides the nutrition for its growth from stored nutrients.

Dendrobiums are of two general types: warm growers and cool growwers.  Most are warm growers and form flowers pikes on which buds develop.  Cool growers form their buds directly on the canes.  Dendrobiums ar higher light plants than phalaenopsis orchids so grow them accordingly.

---------- FOLLOW-UP ----------

QUESTION: Wayne,

Thanks for the information and for volunteering to help us raise our orchids well!

Indeed, they are very different species and the condition I purchased them in were also different. I may have exposed the phal to too much light because the leaves turned a yellowish-light green. I moved it to a window sill facing south where a tree is outside blocking it form direct sun. It's been there for a month or so. The moss is the same stuff from when I purchased it 3 years back and although I did re-pot it earlier this year, but in the same pot and with the same moss. I guess I should change the medium. The roots are firm deep underneath the moss, but the roots closest to the surface are brown and softer. I don't expect to get flowers from the phal any time soon. The new off-shoot plant is barely two inches and growing pretty slowly.

The den, on the other hand, is doing pretty well and the shoot is growing faster while quickly shooting out lots of new roots. I want something to look forward to, but I don't know when it can start to send up spikes or how to stimulate it. It's on the window sill facing west, gets partial direct sunlight and seems to be thriving there. What can I do at this point?

-Theo

ANSWER: Theo, the usual growth habit for dendrobiums is new root and shoot growth, then a rest (which may last for months), then flowering.  When in active growth (as yours is) feed it heavily to maximize the new growth. It also needs lots of light to support the new growth.  When the growth period has ended, try to avoid watering or feeding (an occassional misting is OK). Keep it warm with lots of light.  Mine do well in a west window during the fall, winter and early spring (when the tree sading the window has lost its leaves).  During the warmth of the summer, you can summer it out with lots of light and fresh air. If you do that, however, protect it from the rain during its dormant period. When night time temps fall into the 40's you will need to bring it back to your west window.  Since every dendrobium hybrid has a different mix of genetic material, it is difficult to predict when one will begin its bloom cycle. Also, failure to respect the plant's natural cycle, can result in no blooms or an abnormal bloom period. Each phase of growth, rest, and flowering is quite prolonged and requires a lot of patience.  When in its resting period, it is best ignored.  Not sure if I have addressed all of your concerns.  If not, ask away.

---------- FOLLOW-UP ----------

QUESTION: Wayne, I thought that dens had a rest period and then a period of growth during which they flower. I must have been reading from the wrong sources. My dendrobium has been in it's growth stage for about 2 months. I've been watering and feeding it once a week. Should I do it more frequently? It's been sitting next to an open screen window getting some direct sunlight and fresh air for the past 3 months. Should I bring it outside on my porch where it would get partial full sunlight? How can I shorten the rest period? I bought it last September while in bloom. Is it safe to assume that's when it'll bloom again?

Answer
Theo, thanks for your thoughtful followup. While all stages of growth, rest, and flowering are present in dendrobiums, the length of each period as well as the sequence of the stages vary from hybrid to hybrid. The most common sequence is growth, followed by a rest period, followed by flowering.  Further, some dendrobiums flower only on the previous year's growth, while some just on the current year's growth.  To illustrate, I have a dendrobium in flower that is flowering only on last year's cane (not the most recently matured cane). This plant has been in rest since last fall.  I had it under lights, but was concerned that I might be tempted to water it so I moved it to a west facing window so I wouldn't water it. It started a flower spike in March and the flowers on that spike have just opened.

It may be difficult to be patient but shortening the rest period could send it back into a new growth cycle-- just what you don't want. Be sure, however, that growth has ceased before resting the plant. If anything, you should be doing all you can to lengthen the rest period, once it starts, by withholding water. Improved lighting can help to harden the canes and may result in more flowers when, finally, it decides to flower.  By permitting the plant to guide you in its development, it is likely that it will flower again in the fall.