Dendrobium nobile + no flowering
 

Hello all,
In spite of withdrawing all fertiliser from Autumn onwards and giving only the occasional spray of water, my 20 nobiles have refused to bloom. I live in New Zealand. They are 3 yrs old and I grew them from keikis. they are outside under cover and Auckland does not get frosts. They get plenty of light and morning sun. Am I just impatient?

If they started as keikis, they probably just need to get bigger. They don't need frost (I don't get frost either and and mine get plenty of flowers... if they are outside they are getting a good day-night temperature difference) Can you provide photos so we can see plant size?

hey headbanger.

Nobiles need a couple months of cool period of around 14 degrees C, then once it warms up again they start flowering.

But like you say Aukland should have had it's winter now - maybe you are being a bit impatient.

One thing I am confused by is why you are withholding fertisliser after their rest period. Something doesn't sound right there - they need little fert during rest, then increased fert after rest to encourage flowering

That has been working for your Nobile types? I will admit to being surprised. The typical recommendation is to stop fertilizer when the growth matures or about the beginning of autumn (usually that’s around the same time), reduce or withhold water, lower the temps, and increase the light a bit. Start watering and fertilizing again after the buds are formed or when it sends out new growth.

Personal experience (which is admittedly subjective) has been- first year: gave a cool dry bright rest with occasional light watering with tap water, reduced fertilizer but didn’t cut out completely till winter, started again in early spring. Got lots of keikis, no flowers. Second year: cool dry, bright rest, stopped all fertilizer in early fall, stopped all water late fall (I have very high winter humidity, so I did not get much shriveling), didn’t resume water till after initiation of new growth. Hardly any keikis, a massive amount of blooms. Third year: gave a cool, dry, bright rest with occasional watering of reverse osmosis water and stopped fertilizer in very late fall (oops). Tons of keikis, but not as many blooms. I now follow what I did the second year and have had great results. The cool down plus the lack of nutrients see to be the trigger. I have never noticed fertilizer to trigger blooms on these. If anything, any fertilizer too late in the year or too early, seamed to inhibit flower production. What has your experience been?


Headbanger
How big are these keikis now and are these the normal big, upright nobile hybrids? If they are still small you might just need more time. You could also try increasing the light for the winter. Mine are outside and get good temp variation between day and night, like Roberta. Most of my winter resting Dens get almost full sun during that time of the year, that will obviously depend on the intensity of the sun in your location though. And yes, post some pics of you can:)

Only other possibility I can think of is; are they well rooted in small pots? I had problems getting some of my Dens to bloom until they were pretty root bound in their pots. For example, I received a few large keikis off of the same plant. I mounted two and potted the other. The mounted ones bloomed the following year. The potted one didn’t bloom for almost 3 years when it finally had secured itself in the pot.

Regarding fertilizer, last year I made the experiment to stop fert by the end of August. The result was the same: a ton of flowers.

That is correct.

A dormant plant needs no nutrition. Applying it, especially nitrogen, may reduce or prevent blooming, cause the plant to break dormancy early, and produce keikies.

like I said no fert during rest, fert afterwards when new growth emerges.

We are all in agreement however I got confused by the autumn bit since it is autumns here now but was autumn over in aukland several months ago - just a brain fart on my part

Happens to all of us from time to time...

I notice that the older I get, the more often that happens, too!!!

I have found that precise fertilizer timing doesn't make much difference, but I fertilize lightly on general principles. Not fertilizing when I'm watering less just makes sense... when a plant isn't growing, it doesn't need much water, or any additional minerals. I do water about once a week or two (depending on the weather, rain is a "now and then" thing) When the occasional hot desert winds blow, with high temperatures and single-digit humidity, I water EVERYTHING well. The temperatures in Auckland are somewhat similar in general to mine in southern California, so outdoor growing of these orchids should be similar, too...(Hint: a lot different than growing in a tank in the house in the UK. With experience, one learns to not just parrot what one has read, but to adapt the concepts to one's own situation)

When looking for flowers, it's still pretty early in the season (officially still "late winter") to get much action - depending on breeding (most "nobile" Dens are hybrids with other species in addition to Den. nobile that give other characteristics like flower color and extending the flower season later to coincide with spring shows) these could go well into spring before pushing buds. Without photos I can't be certain, but I also strongly suspect that these just need to get more mature. Depending on how big (and how good the root system) before being separated from the mother plant, they can take quite awhile to establish. That's what underlies my usual advice to not separate keikis, but to leave them on the mother plant. One big, strong plant makes a lot more flowers than a bunch of small, weak ones (which may make none)

Nothing wrong with learning something and passing on the knowledge. Is something wrong with having a chip on your shoulder but karma has a way of restoring negative energy in the universe.

Don't we all parrot on as you put it roberta - you cannot claim you have experienced everything you have preached. That's just ridiculous but if you want to make an enemy fire away. My tank is ready

Btw my dendrobium is not in a tank anyway. I have moved it into a dune buggy now.