summers outside-more harm than good?

[seagull]

i always thought cattleyas don't bloom unless the sun is strong over them, and that oncs were scrubland things from central america that are drought tolerant

[Roberta]

Originally Posted by seagull

i always thought Cattleyas don't bloom unless the sun is strong over them, and that oncs were scrubland things from central america that are drought tolerant

"Cattleya" is a big group - now made bigger by genera that have different characteristics. (They're called "Cattleya" but what used to be Sophronitis still like to be on the shady side) My Catts grow and bloom well under 60% shade cloth - more light than that, they tend to burn (but again, that's in MY yard with almost constant sun in the summer) They do typically need to dry out between waterings. I have found that mine do best in wooden baskets where the roots can escape and sometimes grab the wood (think of them as three-dimensional mounts) But that's in my yard, with my watering habits. In plastic pots, many of the big ones can be watered once a week, maybe twice if it's really hot and dry. (Mine in baskets get watered every two days in summer, every three or four in winter) Many Cattleya species grow high in the canopy, but still get dappled light rather than blazing sun. The rupiculous (rock-loving) Laelias of Brazil (again, now Cattleyas) DO take blazing sun in open areas. (Note that the leaves of this group tend to be vertical, so they present the edge rather than a broad surface to the sun)

So, in summary, there's a range... and generalizations need to be tempered by the specifics of a given plant. A hybrid will reflect the characteristics of its component species, which complicates the picture even more. Universally, though, abrupt change is bad... if changing any orchid from relatively low light indoors to bright light outdoors, it needs to be gradual. Spring is a good time to do it, while there is still some overcast and it's on the cool side, sun angle not so high as in summer. At any rate, in general, if an orchid is otherwise healthy and doesn't bloom, more light is probably needed... but gradually and gently.

[Shadowmagic]

I think trees are the biggest factor. Most orchids grow in trees as has been stated so any full sun growing orchid will be growing in full sun behind a layer of leaves.

One thing that has surprised me most is how my highest sun loving species tended to develop the most sunburn - could be that they have been young but to me sunlight is overrated. Just seems to stunt them if they get too much.

I am still new to the hobby and I know orchids don't bloom for many people - they always blame light. I would tip more on temperature being the important factor but this is something I still need to investigate more.
One thing I do know is that people religiously blame light levels every time when it could be stress, temperature, humidity and lots of other factors too for their orchid not blooming.

Winter rest is important for those that need it - no rest no flowering but you can bet every last penny that the person in question will be scratching their head, wondering what the problem is, blaming too low light levels.

Could be light levels every time, hopefully I will be able to get a better understanding of this in time myself.

[SouthPark]

Originally Posted by Shadowmagic

One thing that has surprised me most is how my highest sun loving species tended to develop the most sunburn - could be that they have been young but to me sunlight is overrated. Just seems to stunt them if they get too much.

This is definitely a matter of figuring out how much a particular orchid can handle in terms of light intensity under certain conditions (of say outer leaf temperature, ambient temperature etc). A 'particular' orchid can mean type or variety of orchid, as well as size of orchid (size of leaves), as well as whether or not the orchid has been gradually sun-hardened.

If certain days or times of the year come with very intense leaf-burning conditions, then know roughly which times of the year to avoid putting orchids in those areas where the plant could get serious damage.

I don't think anybody here 'rated' sunlight ----- so sunlight probably isn't over-rated by anybody here.

The main thing is to just provide orchids with adequate amount of light for them to grow well (which typically includes enough light to produce flower buds and flowers).

Some orchids can handle really intense tropical sun. Sometimes - even these can get a little burned too ----- depending on the time of the year, but maybe not life threatening. I've seen dendrobium orchids in the wild with absolutely scorching sun - blazing down on them in hot weather ------ they have no problem at all. Absolutely sun-hardened. Their leaves are not always necessarily in 'pristine' in condition though (- which is natural) - although --- some can be in excellent shape. They keep growing and flowering - year after year.

[Roberta]

Originally Posted by Shadowmagic

One thing I do know is that people religiously blame light levels every time when it could be stress, temperature, humidity and lots of other factors too for their orchid not blooming.

Winter rest is important for those that need it - no rest no flowering but you can bet every last penny that the person in question will be scratching their head, wondering what the problem is, blaming too low light levels.

No religion here, a lot of observation and some science. First, there's light and then there's light. There's intensity (which can burn plants very easily, watch carefully because it can happen fast) and duration - how many hours a day the plant receives light. And spectrum. An outdoor-grown plant will get the natural spectrum of light, reproducing it indoors can be a challenge. And the whole thing is made more complicated for those growing indoors in higher latitudes, since sun shifts seasonally, at lower angles the higher wavelengths of the spectrum are filtered out by the atmosphere. I can say that with Phals, when I was growing them in the house, I went from essentially no reblooming to about 80% reblooming by adding supplemental light 12 hours a day. (took about a year to see the effect.. other factors such as temperature range stayed the same) Your experience may be different. Experience is the biggie here... observe, tweak conditions a little, observe some more.

Temperature differential is another factor - house temperatures tend to be very even. In nature, even in the tropics, there is significant day-night variation. Seasonal variation depends hugely on location - elevation as well as latitude.

As far as rest... that's another "it depends". I have learned (by killing several plants) that "dry" doesn't mean "bone dry" in most cases (Catasetinae somewhat and some of the summer-dormant Mediterranean-climate terrestrials are exceptions). In monsoonal areas where summers are wet and winters have little rain, there's still dew and humidity. There is a huge orchid-species nursery near me (like about 7000 species, somewhere in the neighborhood of 3/4 million plants) that I visit often (usually leaving significant amounts of cash behind ), and have noted that the deciduous Dens, etc. are in the same area as everything else with the same temperature requirements. Everybody gets watered all year. The secret? Nearly everything is mounted, and so they all dry out quickly. Those Dens don't particularly get "rested" but they bloom anyway. (I think the owner, Andy Phillips, knows a thing or two about growing orchids, so I don't judge based on stuff I have read, I observe what works - even if it breaks the "rules" - and try to understand why so I can apply the observations to my own plants. I do know that Andy's plants don't have internet access, and besides they can't read. But Andy has not only years of experience but also the intellectual curiosity, and multiple plants of the same type with multiple microclimates, to experiment. And I get the benefit of all that by observation.)

So in short - it's all about learning the needs of each plant type, then experimenting - even those who live in areas that are natural for some types of orchids are likely to be growing plants that are native to someplace else. So everything we do is a compromise... the challenge is to find that sweet spot where what we can provide is a set of conditions that our orchids can adapt to.