Paph delenatii problem - Orchid Board

Jeremy · #1 08-21-2007, 12:25 AM

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

smartie2000 · #2 08-21-2007, 12:58 AM

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.

slipperfreak · #3 08-21-2007, 01:13 AM

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...

smartie2000 · #4 08-21-2007, 01:58 PM

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

Jeremy · #5 08-21-2007, 02:16 PM

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?

slipperfreak · #6 08-21-2007, 02:30 PM

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.

Jeremy · #7 08-21-2007, 08:50 PM

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.

slipperfreak · #8 08-21-2007, 08:59 PM

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.

Jeremy · #9 08-25-2007, 03:23 PM

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.

slipperfreak · #10 08-25-2007, 09:35 PM

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.