coming out of winter rest.
 

So, when those dens are coming out of the winter rest, what's the best signal to restart fertilising?

1. New shoots?
2. Flower buds starting?
3. Either?

Edit June 15 2020:
Yamamoto Dendrobiums in Japan hybridizes and produces a great number of these plants. Their Web site formerly had excellent growing information for hobbyists. Unfortunately it is no longer there. You can still look at the varieties they grow, and maybe see one very similar to yours.

I saved the page, and summarized it in a post in this thread:
Uncertain if Dendrobium is still alive

Yamamoto now has a page showing how to force Dendrobium nobile for Christmas flowering in Japan's climate. There is a lot to learn from that page, but it is intended for growers who can artificially heat and cool their greenhouses during off seasons. Note they use coconut husk for growing medium, which many orchidists would say retains too much water for orchids. For many orchids that is correct, but this is a very thirsty orchid.

Nowhere in there can I find where it says when to start fertiliser up again.
Simple question really, which is best? start when the flower buds start to appear or wait till the first shoot, or doesn't it matter?

Bil, the answer is in ES's link:

1st case - For small plants grown without supplemental heat and where night temperatures fall below 46 F (8 C) in winter, apply fertilizer high in nitrogen when night temperatures rise to about 50 F (10 C), probably in March or April.

2nd case - If night temperatures in winter are higher than 50 F (10 C), then fertilize from January.

Basically, 1st case is when new growth begins. 2nd case when the blooms are finished.

I think I'm correct...unless I haven't understood your question.

Saying 'do it at this time or temp' is irrelevant for the amateur grower who isn't doing it wholesale for the market.
I have some dens with just new shoots, some with flower buds and new shoots, and some with just flower buds starting out..

I was just curious when the best time was for starting up on the fertiliser again.
Shoots, buds, or either?

I'm no help bil, but I see what you're asking. Mine is still going dormant, losing leaves. I'm going to error on the side of caution and not do anything until I must.

I see your problem. If they all have grown under the same conditions I would apply both cases depending of the plant. To those that have buds and growths, wel... I would start when the blooms die.

I would interpret that to apply high-nitrogen fertilizer after buds have formed, and before shoots begin. I would be surprised if it is true next season's buds are formed around or before the time shoots start emerging, but I haven't done the work with a microscope. So, I would definitely give high-nitrogen fertilizer when the shoots are emerging.

I have a Dendrobium Love Memory 'Fizz'. While reorganizing my grow space in mid December, I set it between a bench and the glass on the concrete floor, then forgot about it. It got some water because I throw a bucket of water on the floor each morning. I heat the space to a minimum of 60F / 15C. The plant probably had cooler nights, on the floor next to the glass. It is making a lot of either buds or keikiis; I can't tell yet which it will be. But after rereading those care instructions, I'm going to begin fertilizing once I know these are buds.

Yamamoto says they hybridize to make plants easier to bloom, and less temperature dependent. My plant's description is "easy grow and bloom."

Only problem with that would be no fertiliser for the next two or three months.
I think that in the absence of firm info here, I will stick to the adage of stopping feeding when growth stops, and the reverse, ie start when growth starts.
It seems logical that both flowers and shoots would benefit from nitrogen as soon as they start growing, but I am open to correction if anyone knows differently.

If I recall correctly, shoots like nitrogen but flowers less so. It makes sense to me, logically, that you'd fertilize when the shoots begin to grow. Of course, I don't grow this genus and so am taking a wild stab.

From my experience (which is not much) buds and new growths at the same time is not the natural sequence of events.

In my view, nitrogen is not good for bud formation but it's good for new growths. Since your flowers are already formed, but you already have new growths, the logical conclusion would be to start now. I advised the middle term between Jan and Apr just for caution.:)

If you're talking about nobile dens...are you getting new shoots from the base or are you seeing growth development along the canes?

Typically nobile type flower and then produce shoots from the base. Typically being the key word but, as we all know, sometimes these plants have their own minds about things.

If the growths are along the canes...no fert until after blooms have faded. If actual new shoots...I would prob wait awhile in order to hopefully get the plant back on track toward a more usual schedule.

Oh I've got them all, bl**dy minded little s*ds. Buds on some, shoots on some and a couple with both.

Such fun.

Once they are surely buds, I would begin fertilizing. Others might not.

Yeah, that seems logical.

Bil, can you take a picture for me when you get to shoot/bud stage? I think I see swelling on mine but, it might be wishful thinking.

My camera is fairly crappy. Look for conical growths n the opposite side to a leaf.

Buds grow with a distinctive pattern: one in each node of the cane, alternating on both sides of the cane.

Hahaha, glad to hear I'm not the only one... TBH, I haven't even stopped fertilizing, as my situation is even more confusing. I always understood that you should stop fertilizing when they stop actively growing, i.e. when they form their terminal node/leaf, and start fertilizing again when they start producing new growths. Thing is, by the time most of mine had produced their terminal node and leaf, they'd already started with a new growth from the base.
I'm thinking I could end up with a stupid amount of keikis this year... 😂

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My understanding is that fertilizing too late in the summer prevents flowering. The previously-quoted link says to stop fertilizing before August. If not, rather than flowers, the plants form keikiis.

Too-warm nights also prevent flowering. I infer, from reading the Yamamoto descriptions of their plants (the wholesale descriptions are more detailed than the retail descriptions) some hybrids are more tolerant of warm fall/winter temperatures than others, when it comes to flowering.

I suspect shoot formation is related to warm temperatures, and may occur whenever temperatures are warm enough. My sunroom and the central Mexican plateau are probably warmer in the day than are Himalayan foothills.

This would be a good reason to buy plants that fit your conditions, Dolly.

I don't think it's a case of the plants not fitting the conditions - all my Dens have been bought from a local cultivator who has - how shall I put this - rather "rustic" greenhouses - no temperature or humidity controls, no added ventilation, etc. Wall-to-wall blooms for him during February to April.
And who knows? Some of the nubs my plants are forming right now might be blooms - I actually had one bloom mid-September, right in the middle of heavy fertilization and rather warm temperatures. Go figure.
Well, if they all come out as keikis, I'm gonna look on the bright side of it - a shed-load of keikis this year will hopefully mean several times the number of flowering plants next year. Just need to find the space for them... 😂

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Don't forget, you get the best results from harvesting the whole cane and planting/mounting that. Individual keikis just don't do well for me.

---------- Post added at 10:21 AM ---------- Previous post was at 10:16 AM ----------

Well, what I have been hearing is much the same. The biggest effects on the flowers vs keiki ratio is temp and nitrogen. Water isn't terribly relevant (altho there might be exceptions out there)
As soon as they stop growing in late summer early autumn, stop fertilising and water with plain water. Don't be too quick to bring them in, and let them get as cold as you dare for as long as you dare.

That's what I've been doing until now but this summer I stopped fertilizing due to a suspicion of spider mites infestation and, instead of water +fertilizer I showered it with plain water+dishwasher, detergent and alcohol.:biggrin:

Not sure if this was caused by the lack of nitrogen in the middle of the summer but I'm seeing lots of buds, even in 3 year old canes.

Personally, if I see a bug, I kill it with fire. I had a bout of spider mites, and everything got hit with a serious acaricide.
I don't believe in alternative treatments.

I want to hear them scream.

Someone else on this forum recommended the same thing to me about a year back, telling me that a cane that has produced keikis won't flower again. Couldn't bring myself to do it. All those keikis are now 2- or 3-cane plants, and the original cane is again producing something -- too early to tell if it's flower or keiki yet, but whichever it is, it's something I wouldn't have had if I'd cut the cane up.



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If I didn't want to propagate, I would snip the keikis off as soon as I identified them.

I don't cut the cane up either, but plant the whole thing.