Dendrobium Species and Hybrid

[LovePhals]

Hello all!

I am trying my first year at keeping some of my plants outside for the summer to free up some indoor space. I have had my Dendrobium Capituliflorum, Dendrobium Micro Chip and a Phal Noid outside for about 3 weeks and am also thinking about placing one of my Phal-type Noid Dens outside for the summer. My Dendrobium Capituliflorum seems to have a suffered some burn while being outdoors. Is it too hot for this plant species? Too hot for Den. Micro Chip?

I live in zone 7 and am hoping the temperatures are going to be right for them now that it is hitting 90 I want to ensure I am not going to have them suffer from to hot of temps. Should any of these plants not be grown in hot zone 7 weather that will hit 100+?

[tarev]

I am in a very hot zone area, and the way my orchids survive the heat, I make sure I give them a good shower early in the morning, especially when we have a forecast 95F and higher..which we will surely have this weekend.

The only providential thing for my growing area, they will get full sun minimally shaded by the screen cover of my grow camp from around 10 ish to past 12 pm, then the canopy of the trees takes over to provide dappled shade. But ambient temps stays to the 90 to 95F range. There is good cross breeze that helps them too, and I have a fountain running beside the growing area, for added humidity. Our humidity here is also extremely low. If we really do get the onerous over 105F, I give the orchids an extra afternoon shower, they are still in shade anyways, and just something to help them get through, anyways summer light is till 9pm so there is time for the orchids to dry off quickly by night time.

So if you can provide something to shade them..a white screen cover, or an umbrella, that would help them a lot. My Phals and Paphs do not go there, I can better control their moisture needs indoors. But my Dens, Maxillaria, Onc, Zygo, Miltassia, Cattleya stays outdoors. Vanda hangs by the fountain, and Cyms on a vertical post getting more light in another area but still gets shaded the rest of the afternoon.

[gnathaniel]

Hard to say how your orchids will fare outside based solely on your USDA zone; diurnal temperature range, humidity, air movement, light intensity, precipitation, etc. are important geographically-influenced cultural factors not captured in the zone system, which is based solely on average annual minimum winter temps.

That said, the damage you've seen on your plant sounds more like 'sunburn' than heat stress, though pictures would help confirm. Many Dens like bright light but not always direct sun, and even full-sun loving plants should be acclimated slowly to high light to prevent damage.

[NYCorchidman]

I don't think any of your dendrobiums will survive direct sun.
Keep them shaded but bright.

Regarding heat, species making up Den. Micro Chip are cool and intermediate growers.
I have two of them on my window sill. They are still in bloom, although nearing the end, and new shoots are emerging. So far so good, but I'm keeping my eyes on in case it becomes any heat stressed.

I don't think Micro Chip will be too happy in 90-100 for an extended period of time.


Phal type dendrobium hybrids can take a lot of heat, but no sun. Keep them bright. If you can, keep them on the east side of the house where they can morning sun and then, can be protected from afternoon sun and heat.
If not, put shade cloth over the plants.

Humidity might become an issue outside when too hot, unless you can spray water daily.
and mites...yuck!

I don't know what your outdoor growing space is like.
If it is dirt, probably heat is less problem. Congrete, maybe not too good.

[LovePhals]

Thanks for the help. I guess I will move the Den. species and micro chip back indoors. My outdoor growspace is a wood stand Greenhouse placed on a porch. It can be completely glass enclosed but I open the top for airflow and vent the side as well. I also put up a shade cloth when it is really hot and sunny. I tried putting out some of my orchids last year and got a horrid aphid infestation on some of my Dens and oncidiums. I got rid of them and moved them back inside and am wary of putting anything back outside after the damage it did. I have lasting damage on them. The last thing I want is mite damage!!
Here is a picture of the Dendrobium Capituliflorum damage, that I hope is just sunburn, it never had any foliage damage before I placed it outside and the greenhouse does get some direct afternoon sun that shines in.

[LovePhals]

Anyone know if this is sunburn? I am unsure which plants I should move outside. I have lots of genre and heard that they grow better outside?

[NYCorchidman]

It looks like a sunburn.
Keep an eye on that mark and see if it gets larger, which is then an infection, which then you should cut off.

With glass enclosed greenhouse, you should definitely use shade cloth and air vent open.
Otherwise, you will end up cooking your plants to death. It would be worse then being outside as the inside temperature without enough ventilation and shade cloth will go up like crazy!

Oncidiums, especially in spike and in bloom, are like aphid magnet. With daily inspection, you should be able to get them off as you find them because they are relatively large pest and easy to spot.
They are also potential virus carrier, so you definitely don't want aphids on your orchids.

I've never have aphids on dendrobiums, but both dendrobiums and oncidiums can be easily attached by mites if they are stressed with underwatering.
Any plants, not just orchids, that are weakened by not enough water become easy target to mites.
So keep your plants well watered and protect them from direct sun, and this way you keep your plants healthy and happy.

That is the most important.
Provide the best care you can thus keeping the plants healthy. Then they are usually strong enough to fend off pest and diseases.

[jeri149]

I keep most of my plants outside for the season. I am in the northern NYC suburbs. The first few years I did this, they suffered initially. But the new growths became adapted to the increased light. Now when the go out they are covered with 50% shade cloth. I remove the cloth for a few hours in the early AM just to get them used to the light and buy the end of July they are fully exposed. So I think you should keep your plants out, just cover or shade them.
Good luck!
Jeri

[NYCorchidman]

What plants are you talking about?

The kind of dendrobiums mentioned here WILL NOT adapt to full sun. They will simply be cooked to death.
Morning sun is fine for pretty much anything.

[King_of_orchid_growing:)]

I'm not trying to embarrass anybody here, but I do want to say this...

When dealing with Dendrobiums, people have to realize, or try to fathom, just how large this genus of orchids really is. Dendrobium is one of the largest genus of orchids. It contains somewhere on the order of 1,200 species known to science, (according to Wikipedia). There are probably more Dendrobiums that are not known to hobbyists/science yet, but are known to the people living in areas where the orchid(s) are growing wild.

The genus Dendrobium has approximately 1,200 species of orchids distributed all throughout the continent of Asia and some of the Pacific Islands.

There is absolutely no way to make a wide sweeping, general statement about the cultural requirements of orchids within the genus Dendrobium, when these facts are understood.

What tends to happen with the genus Dendrobium is that it gets easier and easier to make generalizations about cultural requirements when the genus is broken down into sections. When Dendrobiums are looked at according to section, it makes it easier to generalize growing conditions when you find out which species grows in similar regions.

It's tough to nail down and understand the genus Dendrobium. That's why no one can really be a "Dendrobium expert", but they can be specialists in certain sections within the genus Dendrobium.

With that said…

Dendrobium capituliflorum is in Section Pedilonum, (the same exact section that the far more commonly available/grown species Dendrobium bracteosum belongs to).

They come from New Guinea/Papua New Guinea and the Solomon Islands, (according to the IOSPE).

These should be grown intermediate to warm, (55 F - 95 F). Temperatures reaching 110 F can be tolerated for short periods of time just fine.

This orchid does not, and cannot be grown under full sun, nor can it be adapted to grow under such harsh conditions. It grows in moderately bright to the low end of bright indirect light. However, Jeri's recommendation of 50% shade cloth might be ok, keep an eye on the orchid though.

Moderate to high humidity is appreciated, (60% - 90%).

Moderate air circulation is fine.

They do have a seasonal variation in watering. Be clear on what I'm telling you - they should be watered year round, but less so in late fall to early spring than they would be watered during the rest of the year, it is not a hard winter rest, which is why New Guinea/Papua New Guinea is so lush throughout the year.

And, yes, the Dendrobium capituliflorum in the pic is displaying signs of sunburn, not heat stress.