Dendrobium griffithianum

[Liodoro]

Hi, I haven't been on the forum for two years. I have a Dendrobium griffithianum that was in a bad way in January. I acquired it in May 2022. The canes are firm but there are no leaves. However, I am seeing a green shoot emerge from the base of one cane. It is mounted in a little moss on a seagrass shallow basket and gets sprayed each day. Is this possibly a flower spike or will it be the start of a new cane? Can you please advise on the optimum care to see this orchid thrive. It has not flowered for me before. Thank you.

[NatalieS]

If it's emerging from the base of a cane, then likely a new growth, but a picture would tell for sure! It doesn't look like you've posted a picture, but I know sometimes pictures don't display properly.

Also, welcome back!

[Liodoro]

Thank you. I'll try and post a picture.

I don't think I've posted a photo before. I hope this works.

---------- Post added at 02:59 PM ---------- Previous post was at 02:23 PM ----------

Shared album - Helen Urquhart - Google Photos

[NatalieS]

A new growth! I'm unfortunately not familiar with the particular culture of this dendrobium, so perhaps someone else can chime in.

However, it will help to tell us a bit about your growing environment. Is it grown in the house in normal room/home temps, or do you have an outdoor growing area or greenhouse? How much sun does it get, if any? Besides the spraying with water every day, do you ever soak it, and if you fertilise, how often and with what kind of fertiliser?

[Liodoro]

That's good to know. Thanks. Well, it's grown in my porch which has shaded East, South and West facing light. The temps. during the days over the last couple of months have been Intermediate (18 - 27 C on average). I run a humidifier on high first thing and then reduce to about 65%. There is an oscillating fan going all the time. This Dendrobium is facing West but gets the Southern light, very filtered as well. I spray every day and dunk in a bucket of rainwater with some fertiliser once a week. I lost my rhythm with care last year for one reason or another and that is why this one (there are about 80 orchids in the growroom) is floundering. I am very happy that it is growing on. I think it's the 'resting' that I need to understand. Whether I move it to a cooler room in the house and at which month I shut down the daily watering. Thanks very much for your interest. I look forward to hearing your advice.

[Liodoro]

Shared album - Helen Urquhart - Google Photos

[estación seca]

Dendrobiums making active growth, like this one, need a lot of water. Keeping them happy on mounts is difficult unless it's very humid, because the roots dry out so rapidly. Misting isn't useful because the water evaporates in a few minutes. Plants on mounts need a heavy watering every day. It would be best if the roots never dry out completely while it is making that growth. I suggest stopping the misting and focusing on watering.

Winter rest doesn't mean no water. It means no fertilizer, and less water. For many Dens in this group, but not all of them, it also means a drop in night temperatures. You can read about Den. griffithianum at orchidspecies.com .

The photo of your collection shows they are almost all seriously underwatered. Many plants have wrinkled, drooping leaves. Orchids don't like to dry out for long. Overwatering doesn't kill orchids; lack of air at the roots kills orchids. I realize you have a difficult growing environment being so far North.

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[Liodoro]

Thank you very much. Yes, I do think I have a fear of over watering. Do you mean that I should submerge this Dendrobium in water several times a week? I think it is more than misting - I do spray the roots quite heavily each day. And I did think that high humidity was a good thing for orchids but perhaps I am wrong. I appreciate your help. Thanks.

	Mistking Looking for a misting system? Look no further. Automated misting systems from MistKing are used by multitude of plant enthusiasts and are perfect for Orchids. Systems feature run dry pumps, ZipDrip valve, adjustable black nozzles, per second control! Automatically mist one growing shelf or a greenhouse full of Orchids. See MistKing testimonials

[estación seca]

Most people who grow mounted plants need to get them completely wet every day. How long do the roots remain wet after you dunk it?

Relative humidity of 65% is not that high. It's good for most plants. But mounted plants will dry out very rapidly at that humidity.

[Liodoro]

Hi again,

Well, I start off at 90% RH and the small porch is definitely like a cloud forest. I suppose I'm concerned that mould will develop if I keep it like that all day and the humidifier will need refilling often each day.

As to watering, well, the roots on that Dendrobium are still wet at 4.00 in the afternoon. As a beginner I am trying to keep the rainwater tepid and keep any fertiliser dilute. I worry that water will lodge in the apex of leaves and cause rot. All my mounted orchids have pretty active roots at the moment. So I guess they are wet most of the day but dry by the following morning. I had written this particular Dendrobium off as being dead and so the growth is encouraging.