The Wanneroo Orchid Society
How to Grow Hardcane Dendrobiums The Easy Way
2. Don't worry about humidity. Whatever your humidity normally is, will be just fine. If it's good enough for your cattleyas and
cymbidiums, then it's good enough for hardcane dendrobiums.
3. There is no need to fertilize. They will grow quite well without fertilizer. (They do in the wild)
4. Don't bother about repotting hardcanes. The roots will leap out of the pot and go where they want anyway. So repotting shouldn't be a worry.
5. Don't worry about water quality. Tap water will do just fine. Or bore water. Or dirty dishwater if you must.
But pay attention, because this is THE REALLY CRITICAL BIT.
In winter ;- Do Not Water Overhead. Keep The Rain Off.
Do Not Allow Them To Stay Wet.
Keep Them Away From Cold Winds.
Always Allow The Pot To Dry Out Before Watering Again.
COLD + WET = ROT
If you take this advise, your hardcane dendrobiums WILL grow. I
I know people who grow them like this all the time. Grown this way, they often don't flower at their best. But they will grow and they will flower.
Around 50% humidity will suffice for hardcane dendrobiums, but 60% to 70% would be even better. Forget about humidity above 70%. It's more trouble than it's worth. At that level you get condensation form on the ceiling which drips down on your plants. That's a real no-no. And they don't need that much humidity anyway.
If you fertilize in the growing season, (the end of winter, spring and into summer) they will grow GOOD. A fertilizer high in nitrogen makes for strong healthy canes. After they mature, (around mid summer to mid autumn) change to a low nitrogen, high potassium fertilizer. This is not really difficult - just read the back of the packet where the ingredients are. There are plenty of fertilizers around, so pick and choose.
Fertilize once a week or once a fortnight, very weakly from the time new growth starts until flowering. After flowering there is often a
dormant period until the new spring growth appears. No need to waste fertilizer when there is no growth.
A word of warning.
Some hardcanes grow BIG. Like, 2-3 meters tall (you have heard of Jack and his beanstalk) If you have one of these, either have a high ceiling or ease up on the fertilizer. Most hardcanes are medium size (under 1 meter) and some are miniatures (under 30cm) so buy you hardcanes according to your ceiling height.
Hardcane dendrobiums like to be repotted. You may not think so when you have just finished repotting and the damned thing won't stay in the pot. Yes, I know. Been there, done that. Try this. When you see the new growth coming, that's the time to repot. New growth, new roots. Make sense?
Alright, try this for more good sense. Hardcanes tend to grow tall, then send out flower spikes from the top. The centre of gravity is HIGH. Result:- They fall over. Solution:- Heavy pot.
I don't like clay pots, which you would think should be the obvious solution, because when they are dry, they tend to suck the moisture from the roots. Try a large deep plastic pot with half a house brick in it (or similar). Now, I know that this is sacrilege. All the books say that hardcanes should be underpotted. And so they can be if you live in the tropics. (If you live in the tropics, you can
dispense with the pot entirely) If your hardcane was living in it's natural condition - on a tree - it would send it's roots out thither and yon. Metres and metres of roots, all latching on to trunk or branch. A large pot is but a poor excuse for a tree. So, (blasphemy) overpot.
If your hardcane wants to fall out of it's new pot, shove a long stick down the pot and tie the cane to it until new root growth locks the plant, the pot and the potting mix together.
Perth's water quality is poor. (There's an understatement). If you are in a position to use rainwater, then do so. Hardcanes grow just fine in rainwater. OK, so you don't have rainwater. Like most folks you have to use second best. Tap water! (Yuk) Never mind. If that's all you have, then it will do. You just have to put up with salt buildup on your pots and leaves etc. Give them a good flush out every now and then. It's the least you can do.
Now this is the IMPORTANT BIT! Are you paying attention?
Here is the recipe for killing a hardcane dendrobium.
Get it wet. Get it cold. Keep it that way. Result? Dead dendrobium. I give you my personal guarantee!
How to Make a Hardcane Dendrobium Sit up and Beg.
1. Do all of the above.