Paph delenatii problem
 

My paph delenatii suddenly stopped growing and I cant figure out why. Earlier this season it stopped growing and I repotted it and then it started growing again. Then for the past week it stopped growing and I am concerned that the new growths are too small to flower the main plant flowered nicely last season. The new growths( the entire plant look like a bush) are small and growing too slowly to reach the same size as the main plant to flower in January. I think the conditions are right since next to the delenatii, there is a paph maudiae that is growing rapidly, and phal. schilleriana which is growing like if it is on steriods. The only thing I could think of that could seize it from growing was putting in in a bit more shade since it was burning from too much light. Does anyone have any experience with these plants or any recommendations? thanks

I find maudiaes grow faster than the parvisepalums too, so perhaps there is no problem.

I know that a calcium supliment is recommened too on these parvis.

Paph delenatii will probably grow slower than Maudiae types (mine vary). However, performance can be improved with more fertilizer, higher humidity, and more light if it is too shaded (Unless it is burning, lower light is not required). It will take fairly bright light for a mottled-leaf type; I grow at 1200 footcandles. Of course, it is easy to burn if grown in higher light than say 1500 fc. Paph delenatii does not like calcium like other Parvis; it likes an acidic medium. Not to say that it will die with calcium added, but it will grow better with a lower pH and doesn't need calcium supplements. I fertilize every 2 weeks year-round, and grow at 60-70% humidity (sometimes down to 50% during the winter.

EDIT: I thought I'd add, delenatii doesn't usually STOP growing; it has no definite rest period. Now that I have thought of this, you haven't lowered the temp or anything have you? Even if you had, I wouldn't expect it to just stop growing...

Joe is right with that.
I forgot that delenatii is the only parvi that does not need a calcium suppliment

I don't add any calcium supplement to the delenatii, and humidity is not a problem 80%-90% during summer and 60&-70% during the winter. I grow mine in really high light at a west window just short of burning. And the temperatures for the past month stayed consistant 80F-90F days and around 70F night, the coldest it got was 67F at night last week other wise it doesnt get cold at night until late september. I fertilize weekly with dilute solution of 30-10-10. I remember that it grew year round last year. So they are supposed to be slow growers. Another thing I was wondering is whether the offshoots are supposed to be smaller than the main stalk is that the case with your delenatii? How large is the leaf span of delenatii?

Your conditions should be just fine; I think your lighting is not a major problem as long as you don't burn it, and as long as that humidity is kept up. My oldest delenatii has a leafspan of 8", which is right around the maximum; I think 9" is the max. They will bloom from a 5" leafspan though. New growths will start off much smaller than the original growth of course, and will enlarge over time; as for the mature size of new growths (as in the size at flowering), they should be the same size of the original if not larger if the plant is happy, but if it is stressed it may produce smaller subsequent growths. It may also be producing small growths due to the high light; you may also get smaller, less-colorful flowers from this.

So, I think the diagnosis of the problem is there is no problem; you just have a slow-growing plant. If your plant is flowering and doesn't have any apparent problems with rot, etc. then just continue what you're doing, it'll be fine. If you continue to get small growths you should consider lowering the light.

It seems like I have been doing everything right. Maybe the plant is growing too slow for me to observe, if everything is well the plant should then flower this winter. If not then just get rid of it and maybe try a delenatii hybrid, Paph magic lantern, I hope it is easier than the delenatii. Thank you everyone.

Don't give up on delenatii Jeremy! If you are really displeased with the plant's performance, perhaps you could try a different clone? Some have better growth rates than others - look for newer Vietnamese breeding. I find that delenatii hybrids don't cut it if you are looking for delenatii's specific appearance. However, Magic Lantern is a great hybrid which is easier than delenatii to grow and grows faster. It more resembles the other parent, micranthum.

I think that the new Vietnamese cultivars lack the fragrance that the old French culitivars have. I placed my delenatii more closer to the window since of the decreasing sun intensity. I hope that will stimulate it to grow again. Right now there are leaves that measure 2.5 inches and they are upright. When the plant decide to grow again, the leaves change angle be horizontal and then the plant will have a span of 5 inches. So it may already be blooming size, however it does not rival the original plant span size of 9.5 inches. I dont think the plant will reach that growth size. If the plant refuses to bloom then I think I will grow a different delenatii cultivar or a delenatii hybrid. Are there any delenatii hybrids that has fragrance? I want a fragrant paph since fragrance is rare in this genus and delenatii is one of the few that has it.

It's true that many of the Vietnamese cultivars lack fragrance. The thing is, the French clones have fragrance but are less vigorous and have poorer color. What I would do is shop around a bit, and look for some clones that are described to have good color AND fragrance. They can be hard to find, but there are a LOT of delenatii clones out there - you'll find the perfect one eventually. You may have to settle for seedlings though (you may or may not be comfortable with seedlings, but delenatii is not a temperamental one as a seedling).

Now, as for fragrant delenatii hybrids, try Joyce Hasegawa (delenatii x emersonii). It looks like delenatii but the pouch is lighter and the flowers are larger. I believe Lynleigh Koopowitz (delenatii x malipoense) is also fragrant in some clones. It looks like a pink and white malipoense. Some clones of Ho Chi Minh (delenatii x vietnamense) are fragrant. It is basically a really awesome, superior delenatii with better color, size and vigor. I highly recommend this one period if you like parvis.

I think that I may have to settle for the new Vietnamese clones without fragrance, if my French delenatii doesn't flower this winter. If that is the case then maybe I will get the fragrant less delenatii with good color and a fragrant delenatii hybrid because fragrance is one aspect of an orchid I find really important. However I am keeping my hopes up and my fingers crossed that my delenatii will grow and flower.

I contacted the vendor from which I bought the delenatii from and they say that it is a typical and common growth habit of delenatii to grow slowly or grow intermittenly :( but they said it should flower this winter :)

I'm glad you got this figured out, Jeremy. :) Delenatii is a great species, worth the wait for flowers. Be sure to try some of the hybrids I mentioned though - I'm sure you'll like them!

I think I will try magic lantern. It is very appealing. Like micranthum, it has very large pouch. What is the general culture for magic lantern, since micranthum grows in cool conditions, and micranthum may have passed on the necessity for cool winter temperatures? Can this grow in intermediate to warm conditions?

Yes it can. You'll find that Magic lantern is easier to grow than delenatii, and MUCH easier than micranthum. It's quite adaptable. You can grow it pretty much like a standard Maudiae type, maybe with a little more light, up to 1500 fc.

Forgot to mention, the cooler you grow Magic Lantern in, in general the better the color. Try to find ones with micranthum listed as the first parent; they will have better form and color.

I can't find any growers in my area with Micranthum listed as the first. However the ones with delenatii as the seed parent (first parent) are still very nice. I am not sure whether magic lanterns are mature in 2.5-3.5 inch pots. Are they mature in that size? I forgot, I think that my delenatii is starting to grow again? There is a leaf that appears slightly bigger. Either that or I am just imagining things? Lets hope I am not imagining

A Magic Lantern in a 3.5" pot is more than likely ready to flower. 2.5" is iffy. As for your delenatii, it could be growing, it might not be. However, the peak delenatii flowering season is coming up in a couple months... I'm starting to think about cooling mine off a little to induce flowering. If you have any growths reaching maturity you may want to do this around late September/early October (I know, I start thinking about these things early!) for a December/January bloom. Of course, the peak season extends into May and they can flower at any time... But you've already flowered yours so I'm sure you know about this. Anyway, I talk too much! Good luck with your Magic Lantern!

My growing area starts to cool off around mid September (depends how cool it is outside at night). I calculated my averages for every month of the year using data I collected from my max and min thermometer ( I am such a nerd with these things) and night average for September is 66F and for October and November 64F and December 61F and December is the coolest average however on those bone chilling winter nights (which I am sure you have experienced in Canada) the night temperature drops to 55F-58F. Even though there aren't any mature growths on my delenatii, I still have to cool the growing area since there are other plants that depend on the seasonal change (ie. Dend Parishii). However I remember that my delenatii grew even when it got cold. So maybe it will continue growing.

When I go to the vendor this weekend to get a magic lantern, I may also get a new delenatii because in the picture on their website the delenatii had more coloring on it the petals were also pink. But the picture couldn't be exactly like the plant. So I am probably going to ask the person who actually propagates them. Is coloring on the petals a sign of that it is a newly reintroduced species?

Oh yes, we experience cold up here!

Pink on delenatii petals? Sounds like either vietnamense or Ho Chi Minh (which is delenatii x vietnamense). I have never seen a delenatii with pink petals before, maybe a tiny little blush at the base... Perhaps he put the wrong picture there? Or maybe it is just a cool form? What website is it?

The picture is on Oak Hill Gardens. It is on their website. It looks like the entire flower is light pink. And it does look like it is a complete delenatii and not a Ho Chi Minh. They had had a picture of a white delenatii with a pink pouch but they changed it.

Oh yes that is most definately a delenatii. The tepals look white to me - perhaps it is the lighting?

delophyllum
 

I have a hybrid delophyllum, I like the pink color from delenatii and the eyelashes hair like and, bluish green leaf from the glaucophyllum

Here is my delophyllum:
http://www.orchidboard.com/community...m2_Medium_.jpg

http://www.orchidboard.com/community...lophyllum1.jpg

My paph delenatii is growing again!!! I encouraged it to grow by giving brighter light and by letting it dry out more between watering. So the key is to give brighter light and let it dry out between watering. I got my magic lantern a few days ago. Will it grow in the same conditions as the delenatii? When does magic lantern flower? Is it during spring?

Yes Magic Lantern will grow under the same conditions as delenatii. It will grow under a wide range of conditions. Flowering times vary.