Successful Den. aggregatum culture?

7 years ago

I have a Den. aggrevatum :) that I've been try to flower for a couple of years with no luck. Tried one several years ago and it lost the battle being over-wintered. I'm an indoor winter grower and put my plants outside from May-Oct. I got this plant as a seedling 2+ years ago and it is currently growing in a 3.5" clear pot with @15 pbulbs. It seems to do very well outside with lots of sun, as it adds 4-5 p-bulbs each summer.

This fall/winter I have been keeping it in a bright east window with LED supplementing for 13 hours and temps running between 55-70F, usually on the cooler side as it sits very close to the window. I've watered it once and lightly misted it weekly. P-bulbs are shriveled quite a bit but it looks fairly healthy as I can see green tipped roots through the pot and the leaves are still quite stiff and green. I see no signs of flower spikes.

When should spikes start to appear?

Where do the spikes appear?

When do I start to water and fertilize regularly?

Any comments regarding how others are growing their aggregatums and getting blooms are quite welcome.

Thanks,

Bob

Featured Answer

jane__ny

last year

last modified: last year

I posted the photo of the Cattleya but it disappeared. I'll post it again.

I stuck it in a wood box because it was blown out of it's pot. In the photo, it is bare root.

The color is amazing. Totally neglected for over a year. No watering or fertilizer.

Jane

Sort by:Oldest

Comments (69)

westoh Z6
Original Author
7 years ago
Thanks guys,

I watered it a bit yesterday, will start a regular watering routine this weekend.

I'm going to try to keep it potted although I'll probably up-pot to a 4"-4.5" pot., I got @5 pbulbs last growing season, hopefully another 5-10 this year for a total of 20-25. Next fall I'll do a really bright and very dry winter, if no flowers next spring then I'll consider it not worth the effort and give it away or compost/'Kev' ('Kev'ing' something is composting for us old-timers from the previous site) the 'aggravation'.

Bob
shavedmonkey (Harvey in South Fl.)Z10b
7 years ago
From what you write I'm confident you know how to grow. Before you give up on the species, try another plant. The one you have could be a dud. That happens. I'd bet you can bloom that species. I would not bet on that particular plant though.
Related Discussions
dendrobium aggregatum in texas?
Q
Comments (2)
hi there-i live in san antonio and i grow mine outside. my plant was also a 5 bulb division. its mounted on cork and hangs under a tree in my backyard with everything else on my mount racks. we have more humidity here but not much. i have found that this is a hardy plant in my area. i let it get full sun even in the summer and it hasnt burned or been set back, as well as down to 38 in the winter when i forgot about it. it has doubled in size in the year and a half ive had it, but no blooms yet. our much larger plant at the botanical garden just came in to bloom last week, so it think it just has some growing up to do. i water it alot from spring to the beginning of winter-november, then water very sparingly until feb-march. they need a dry winter to flower, but i think mine is still young. hope this helps. are you going to the arlington show? ill prob drive up there.
...See More
Dgmra., Bllra.,Colmonara, same Culture?
Q
Comments (9)
Thank you Richard. I have so much to learn about the various types of Orchids I am growing. Digging deeper, I agree with Arthur, that my Colmonara needs less light than has been given. Read somewhere that some Colmonara need to have a winter rest. True? Arthur, your GH looks wonderfully inviting. What do you have growing on the back (darker) wall? I am especially interested in the way you hang the orchids from a "wire wall". It seems to give you maximum usage. Could you please show it in greater detail? As for the colmonara, I could not find what the Wildcatt 'Hung Sheng'# 7 is comprised of, however, another Wildcatt has Miltonia, Ondontonia and Ondontoglossum in it, which tells me less light, cooler, drying out before night fall. Am I right on this? If so, it'll go lower to the ground hence forth. The Miltassia 'Dark Star' has been troubling me for years. My hunch is I don't keep it evenly moist at the roots, while it gets lots of sunshine and heat over the summer. Yes, I do have a misting system. I can only set it to come on 4x per day. During the summer I had it running at 11:30 A.M., Noon, 1:30 and 3:00 P.M. for 15 min. each time. Orchids got wet yes, but, the temps climbed from 90 to 102 many days. All plants were dry by night fall. Next spring DH is installing a new, better system, which clogs up less and produces a thick fog, rather than fine mist. Last spring we installed a small swamp cooler. I don't like it because when the GH heats up, the cooler is not effective. Besides the cooler, I have had 3 stationary fans running plus an overhead exhaust fan that can be programmed. So I got by over the summer. During the winter a small milkhouse heater keeps the temperature above 50 deg. If I knew how to post a photo here I'd let you see my set-up. I see both of you (plus a few others) diligently responding to us newbe's. I agree wholeheartedly with the writer who posted a public "Thank You". I consider this site equal to a University class. The information available by you is invaluable. Helga.
...See More
Aggregatum, Aggravation
Q
Comments (6)
I like the % idea. So, I'm sticking den unicum in the batch, which means I got 25% success. I actually forgot about this den. I hung it outside in full sun and the only water it got was rain or when my husband forgets and sprays eVerything with the hose. Luckily, neither rain nor hose happen often so the plant was dry. It's mounted on a piece of wood. I had it potted and couldn't get it to flower and it almost went to orchid heaven. I think neglect did the magic. In the meantime, I have three others doing nothing. They sit there mocking me.
...See More
How do I grow my Dendrobium Aggregatum orchid
Q
Comments (15)
Valieta, Let me throw my .02 cents worth in here. I grew Den. aggregatum for a number of years. I bloomed mine in South Carolina, Kansas, Florida, and Virginia. The plant comes from around the northern part of India, and ranges from the high altitudes to down in fairly low altitudes. This means that some of them get cool dry periods in the winter, and some get less. the altitude that your plant actually came from may affect its blooming, but then you may have one from low altitudes, and it'll be easy. I had a small greenhouse, so all my plants pretty much lived under the same conditions. my aggregatum may have bloomed out of season a few times...Its been a very long time ago...but really, I did not care because it was beautiful when it did and that was what mattered. I would grow it like a Cattleya, then in the fall/winter shelter it from water as much as possible. The pseudobulbs will shrivel a bit, but expect that. keep the plant out of the sunlight and as cool at night as possible, and hope for the best. One trick that works for some cymbidium growers who live where their plants can't get cool nights to bloom is to put a tray of ice in the pot each night for a few weeks in the fall. That may or may not work for you, because you are in effect watering the plant with ice. You might try a season or two without the ice, and if the plant refuses to bloom, try one season with Ice and see. read up and get familiar with the seasonal weather the plant experiences in its growing area, and do your best to match that where you are. Sometimes its a snap to get plants to bloom in different climates than they are accustomed to, and sometimes its just impossible. Either way, its fun trying. Bill
...See More
jane__ny
7 years ago
Lets take some bets!

I'll bet 5 bucks it flowers next year.

Might be fun.

Keep the plant another year, Bob.

Jane
miniplants Central KY 6a windowsill-grower
7 years ago
Why so optimistic? I have one in exactly the same situation as Bob's: I've had mine for 2 years, bught as blooming size, hasn't bloomed. This past year I gave it a good 3 months of cool temps at night coupled with bright light and humidity, then NO water from Dec-late March (but good light and humidity). Shriveled pbs but otherwise looks fine. Finally one old root put out a white extension and now I'm watering it again. Meanwhile, Dendrobium unicum, which received the identical treatment alongside the D. aggrevatum (literally in the same container), "woke up" with green buds at the end of January and now is loaded with buds that are turning orange. I feel we're missing some key trigger for D. ag. Whatever it is, Jane's culture conditions clearly supply it. Enough people have trouble with this Den that I tend not to favor the bad-gene plant theory. Sue
shavedmonkey (Harvey in South Fl.)Z10b
7 years ago
When breeding is done there are a lot of plants created due to the high number of seeds and good lab conditions a large number germinates. In large numbers there are always a few that do not make the grade. Normal. My theory is being that this plant has a reputation for not blooming couldn't it be possible that the rate of bad plants are higher? The failure rate would have to vary from plant to plant. It is logical that the difficult one might have a higher rate of failure. It is all a guess and no way to be certain. But possibility exists.
jane__ny
7 years ago
That is why people call it Den Aggravation.

I'm not sure what the secret is. Something about Florida works. At my Orchid Society meeting, there were so many in bloom. I do think neglect and dry winters are critical. I also think mounting them works. All the blooming plants were mounted.

In cold climates, mounting would be difficult due to low humidity.

Jane
miniplants Central KY 6a windowsill-grower
7 years ago
My non-flowering Den ag is mounted on cork and is propped over pebbles and water within a terrarium that has 4" openings at top and on one side. My plant has 11 leaves. I just googled Den ag (again) and read that during December to February the night temps need to be below 60 degrees F for Den ag to flower. I was giving it the cool night temps outside September through November. Then I have to bring it inside as we get freezing temperatures in December. Aargh. Maybe that's the condition I've not provided that Jane's porch does. So sayonara Dendrobium aggregatum. Sue
westoh Z6
Original Author
7 years ago
Sue,

I'm thinking ours need to be more mature. I did allow mine to drop below 60 degrees over the winter nights so that wasn't my issue, I'll be keeping mine sooo dry and cool next winter it will either bloom or die :) As far as maturity, I'm hoping to be up to around 25 p-bulbs by next fall.

I'm not so sure it is a genetic thing for my plant, it was purchased from an extremely reputable vendor and I wasn't able to bloom a previous one either. I chalk it up to me not providing the right conditions (definitely the issue with #1) or the plant not being mature enough (hopefully the issue with #2).

One more year for me.

Bob
jane__ny
7 years ago
Sue, it could be the cool down but I wonder how much light your plant is getting. Mine gets blasted with sun all year. During winter you have to keep the light levels high even though the plant is dormant. At least that's how I grow it.

In Florida our winters are extremely dry. We have had practically no rain for 5 months. Mine does grow outside and if we do get a shower, it gets watered. I don't move it in or out. But we rarely have rain at all from about November until May/June.

Its terrible for my other plants but this one seems to thrive on the dry weather. It is similar to its native growing conditions.

Our night temps begin to drop around December. Not by alot but it continues through Jan/Feb. Some nights fall to the 40's. The days are sunny and in the 60's-70's. But the nights are at least 15-20 degrees cooler during those months.

If I were trying to grow this in NY, I would leave it outside until the night temps fall into the 30's. I might bring it in at night but put it back out during the day. I did that with Phals and my Angraecums until I saw spiking.

Once I saw spiking, they came inside to stay for the winter. The Ang went into the sunniest window. Same with the Phals but no direct sun.

I think the Den needs that temp swing. Treat it like a Phal with night temps, but give it more sun no water. I bet you and Bob will get those plants to flower next year.

Jane
aztcqn
7 years ago
Mine is fat and green, but barren. Bought it in spike then 2 years of no flowers. It grows right alongside my kingianums, so, I imagine it gets the drop in temp and good amount of sunlight. It did stay out during the rain storms, however......
melle_sacto is hot and dry in CA Zone 9/
7 years ago
I'm curious about the cool down temps...how cool does the plant need? I've had mine over 5 years but nary a spike.
westoh Z6
Original Author
6 years ago
last modified: 6 years ago
Just to keep the thread alive... Here's a pic of the aggragatum today, 4 new pbulbs (lots of red on the new ones from max sun) and I expect at least 4 more before the end of summer. It is still in a 3 1/2" pot.

Hoping for flowers next Jan/Feb with a very bright, very dry winter rest starting in mid-November.

Bob
jane__ny
6 years ago
Looks good Bob.

Just watch the watering in Fall. Let it go bone dry around Nov. and only give a bit of water if the bulbs look really shriveled.

Mine grow bare mounted and only get watered when it rains. In Florida it rains almost every day, but is extremely hot and humid. I think these plants do better when stressed.

I do not hand water.

Jane
westoh Z6
Original Author
6 years ago
Time for an update.

Current pic, added 4-5 p-bulbs this summer, hasn't been 'intentionally' watered since October and it shows in the wrinkled p-bulbs. It was accidentally watered for @ 1 second in November, but it ran right through the pot. It has been lightly misted once when the humidity in the grow room had been lingering at around 20% for 10 days or so.

No sign of spikes, but it doesn't look too bad I'm willing to wait another month or two.

Bob
jane__ny
6 years ago
Looks good, Bob.

Mine is mounted and does get whatever rain falls which is rare in winter here.

Jane
westoh Z6
Original Author
6 years ago
Jane,

Yours seems to be much more 'plump' than mine. Still no sign of spikes.

Bob
jane__ny
6 years ago
Bob, I haven't noticed any spikes on mine either. I'll take a closer look tomorrow.

Been a weird winter in Florida, we've had some cold weather for the past two weeks.

I had brought it inside the house about a week ago along with a bunch of other orchids. We haven't had any rain until today. We had very brief showers on and off during the afternoon. Today the temps hit 80. Moved everything back outside.

I'm wondering if the cold nights slowed things down. However, my Phals are covered with spikes, so who knows? I'll check the plant tomorrow.

My Aggragatum does not get hand watered but does get rained on. Florida has a clearly defined dry season in winter, however we do get a few sprinkles now and then.

Your plant looks healthy. I would give the roots a spritz now and then. Not a true watering, but spritzed.

Mine is mounted so doesn't hold any water as the mount doesn't get rained on enough to soak up much. But it does get an occasional shower.

Looking back at old photos, I see it flowered last February 28, 2017.

Jane
jane__ny
6 years ago
Checked mine today. No spikes that I could see. Just two fat snails which met their maker! Hope they didn't eat the spikes....

Jane
westoh Z6 thanked jane__ny
westoh Z6
Original Author
2 years ago
Patience is a virtue :)

Same plant in 8" octagonal basket, put there last fall. Had 1 spike a month ago but it failed, this one looks like it will make it to blooming

At least 8 years since purchase, 1st blooming.

Haven't been on much, got 'into' bonsai's 3 months ago, Chinese Elm on left.

Bob
getgoing100_7b_nj
2 years ago
Wow, you have been patient with this one! Post pics when it's in bloom. That is a good sized spike.
jane__ny
2 years ago
Wow, looking good, Bob!

Let us know. Mine is finished, bloomed in March as usual. Now it gets watered whenever I water all my other orchids.

Please let us know!

Jane
forever_a_newbie_VA8
2 years ago
You thought about giving it up 4 years ago? very happy for you. please post a picture when it blooms, Changsong
westoh Z6
Original Author
2 years ago
Looks like only a few more days before blooming, keeping fingers crossed that all goes well. Pic taken this morning. Difficult to photograph indoors. @25 buds currently.

Bob
jane__ny
2 years ago
You got it! Whatever you did worked! I have a new one, about a year old. Surprised me with lots to of blooms. I might put it in a basket as I like the look better.
Meyermike(Zone 6a Ma.)
2 years ago
Wow, look at that! Nice job after all this time Bob))
westoh Z6
Original Author
last year
last modified: last year
Started blooming 4/25, blooms have all fallen off now. I was not impressed, was expecting a more robust flower. Mine seems to be a light-colored type, I like the deeper yellow/orange ones like Jane's above.

Bob

Entire spike:

And a close-up:
jane__ny
last year
I think it’s pretty. I love yellow flowers. Bob, maybe it’s the difference in light levels? Light is so strong in Florida, not sure it can be duplicated with lamps. I was browsing Normans last night and he has a bunch which are all orangey.
I think yours bloomed out lovely. Congrats!
Jane
James _J
last year
Mine open a pale yellow but darken up in after a few days. Could something have happend to make them drop early?
westoh Z6
Original Author
last year
Hello everyone! Back for my yearly update: It is spiking again, much earlier than last year. We'll see if more than 1 spike emerges and hopefully has a deeper color. Will post a pic when blooming.

Bob
James _J
last year
Good news!

Mine is doing nothing so far, but then again I havent really looked close for a while.
Meyermike(Zone 6a Ma.)
last year
Lol. No kidding.
Bob. Too bad the angraciums are not that easy to flower at times!!
I’ll be back with a few pics myself.
Bill. Rooting something for you )
Bill M.
last year
Mike - the Kingianum is sending up multiple shoots all over the place. I had seperated them when I recieved them and gave 2 to a pot. Well, they appear to suddenly be growing like weeds! I'll post a pic tomorrow for you.

Thank you my friend....
jane__ny
last year
Bob, looked at mine today and counted 15 long spikes. Decided to start watering!

These are my favorites, but I wouldn't try to grow/flower them up north. I'm amazed at how much easier it is to grown so many varieties of orchids in Florida.

Please post back with photos!

Jane
westoh Z6
Original Author
last year
Hey everyone!!!

This is 1st spike and only spike so far, based on last year I also expect more in another month or so. I'm guessing these will open in 5-7 days.

BTW: I'm retiring next month so more time to devote to fishing, bonsai and orchids. Pretty much in that order :)

I'll post again when flowers open.

Overhead (50+ bulbs in 8" basket, spike in bottom center):

Spike (you can see it coming out of the side of a bulb):

Take care everyone,

Bob
Meyermike(Zone 6a Ma.)
last year
My goodness. Great job!!
I’m happy for all of you. Jane. I wish I was in Florida!! I’d have thousands planted all over my palms!
Here are a few of mine in bloom. Smells so good !
Meyermike(Zone 6a Ma.)
last year
I also threw in my paper bush I planted in the cold greenhouse. All of then higher zone plants love it in there many in planted!
Here is my paper bush. Ten times stronger than a gardenia.
Meyermike(Zone 6a Ma.)
last year
More )
Meyermike(Zone 6a Ma.)
last year
More in bloom
Meyermike(Zone 6a Ma.)
last year
More today
Meyermike(Zone 6a Ma.)
last year
Wish I could go back and give names but I can’t edit on my cell. Ugh.
Meyermike(Zone 6a Ma.)
last year
Sorry everyone. I thought this was the thread I started about what’s blooming.
Mike
jane__ny
last year
Oh Mike! What a paradise!! It feel so lush and tropical. You have Hawaii in your greenhouse. Great growing👏👏👏
westoh Z6
Original Author
last year
Started blooming last Thursday, took this picture Monday AM, 22 flowers. Still disappointed in the flowers, I think I'll get more spikes in April, we'll see how things look then.

A lot of effort and then I'm not happy with the flowers, oh well it was fun getting it to the point of flowering.

Bob
Bill M.
last year
Maybe the plant isn't happy with you either! ;-)

It looks fine. The joy as you mentioned is in nurturing them and bring them to the point of flowering. The flowers themselves are just the icing on the cake. You did a great job in getting it to this point. Are they fragrant at all?

Best of luck with it and keep up the good work.
jane__ny
last year
Mine just started opening buds earlier this week. I’m growing in South Florida which makes a huge difference. Don’t kick yourself, Bob. Sun, heat, humidity and totally dry since November. The intensity of sun here can’t be matched up north.
What I’ve noticed on mine, the buds which get the strongest light are deeper yellow. My favorite orchid.
Bill M.
last year
Jane, what an amazing plant! Is it outside pretty much year round? Watered only when it rains or do you water and or feed it yourself at times. Boy! Now I want one too!

Best of luck with yours.
westoh Z6
Original Author
last year
I've had my fun with this one and proven to myself I can flower the Den. Pretty disappointed in the flowers so I'm ready to trade this one.

Anyone have a small tree/bush they would trade straight up?

Bob
jane__ny
last year
Bob, you didn't show the whole plant. How long did you have it? I've had mine for 11 years. This is the best blooming I've had. It is breathtaking! I can't stop looking at it. The color glows even at night. But it's a long time.

I have a neglected Cattleya that bloomed this year that blew my mind. It was blown into an area behind trees due to the hurricane in Sept. I didn't even know it was there. One day, a few weeks ago I saw something purple behind the trees. At first, I thought it was a piece of fabric or shirt. I walked back there and saw this Catt full of buds with some beginning to bloom. It was out of the pot and covered with leaves!

The Aggregatum took 11 years to look like this. I love these challenging orchids more than the beautiful Catt buried in leaves. Hang in there!

Jane
Bill M.
last year
Wow! What a beautiful plant