Light Requirements & Shade Cloth
 

I have a new orchid, named Angcm. 'Tomorrow Star'. The light requirements are stated as 'Strong - 2000+ foot candles'. Does this mean that full sun is okay for this plant? (I thought it might be, since it simply has a plus sign, instead of a top end to the range.) If not, what percent shade cloth would work best?

On that subject, if the plant is specified as needing bright filtered light, is 30% shade cloth okay? I also actually double over the shade cloth towards the hottest sun of the day.

Just for reference... in southern California, full sun is about 10,000 ft-candles. So 2000 represents what you would get with about 70% shade cloth. What I would call "bright shade".
I can't find an Angraecum hybrid with that name. If it is in in single quotes, that's a cultivar name, there should be another name after the genus. (The "start" part indicates to me that it probably has A. sesquipedale in its parentage) But most Angraecums do grow moderately shady - brighter than a Phalaenopsis but shadier than a Cattleya, Oncidium would be about the same.

Knowing the actual name of the the plant (species or hybrid) would give some information about growing temperature - Angcm. sesquipedale is marginal outside in winter, but when crossed with other species such as A. eburneum, becomes more cold-tolerant.

Wouldn't 70% shade give 3000 fc?

You're correct, Ray.

I have 60% shade cloth over most of my yard, get the additional reduction in intensity from trees and location relative to house and fences, etc. Since the sun isn't at its maximum all the the time, I do tend to fudge toward "more light" knowing that it won't be high all of the time. So that's the other factor... light duration (and variation over the year), not neatly accounted for in calculations. ("Full sun" isn't 10,000 fc all the time either) From a practical point of view, 70% in my yard is too much shading for anything other than Paphs.

Even the more accurate designations on plants need calibrating... I got a plant from Andy's Orchids that said "full sun" ... and burned it. Andy's climate is very similar to mine. But a visit to the nursery showed that that there is no place that gets sun as intense as in my yard for as long - there are lots of trees. When in my yard, the middle gets the full blast from half an hour after sunrise to half an hour before sunset in summer. Too much unshaded even for a Cymbidium or L. anceps. (Those get 40%)

Unless you're right on the coast in southern California, or it's always breezy, very few orchids will tolerate your unscreened sun in summer. Breeze carries off the heat formed by sun striking the leaves, and they remain near air temperature. But when the air is still leaves quickly burn in the sun.

The larger Angraecums are from the narrow eastern wet strip of Madagascar. The land rises rapidly from the sea west to the spine of mountains running the length of the island. There is almost always an onshore breeze cooling the plants growing up in trees.

Even on the California coast, "full sun" for an Angraecum is too much, I would not even give it that in San Francisco where it is foggy much of the time... but there it is mostly too cold for the genus anyway. (But then, I don't know of any place where "2000 f-c" equals "full sun") Time for a "sanity check" of the instructions.

Well I'm a bit unsure lol, so here is the listing: Angcm. Crestwood 'Tomorrow Star, GM/ 19th WOC, FCC/AOS, CEE/A OS.Note: husky plant with night fragrance blooms.'
(Veitchii x sesquipedale)

So for this one, the seller states warm to intermediate. I'm curious, does this mean it ranges from the coolest of intermediate to the warmest of warm? Or is it more like a 'medium rare' vs either medium or rare, if that makes sense lol. I would imagine there are plants with wider ranges than others, right?

As you stated, I would definitely appreciate getting a sense of minimum temperatures! Thank you again :)

Angraecum Crestwood (That is the name of the cross, 'Tomorrow Star' is the cultivar or specific plant (that was cloned) is 3/4 Angcm. sesquipedale (the Darwin orchid) and 1/4 Angcm eburneum - which gives it more flowers and also a little more cold tolerance than straight A. sesquipedale. It's sort of Angraecum sesquipedale on steroids... How close to the coast do you live? I live about 4 miles (6 km) from the coast, I grow A. sesquipedale outside except for a couple of the coldest months (particularly since it tends to bloom in December, the plant is fine down to mid 30's F but that is rough on developing buds) If it were my plant, I'd grow it like A. sesquipedale, and bring it into the house in maybe December, put it out once it blooms or in around February, depending on the weather... can be fudged based on the temps. (Disclaimer: I am a "What can I get away with ?" orchid grower. It turns out that I can get away with a LOT.)

Would it be happier a little warmer? Sure. But it can acclimate - and the A. eburneum parent makes it even more forgiving. ( I have a friend who lives a few blocks from me with an enormous A. eburneum that lives outside all year around and blooms like crazy. I keep offering to help him divide it... some year...) Southern California growing is really different than for most of the US, and so you have to evaluate the cultural advice from that point of view. Do check out my website (link in my signature) and look around the Index of Plants to see what I grow outside and what really needs the GH. If you live coastal, you can follow it pretty closely. If you're inland you have to be a little bit more cautious on the low end.

Understood, I will be cautious.

---------- Post added at 05:03 PM ---------- Previous post was at 05:01 PM ----------

Well I kept this plant for one day behind 30% cloth for a whole sunny day. Actually I fold over the cloth to increase the shade during the warmest part of the day. And this spot only gets light starting late morning to afternoon, but then no additional shade. I do have a spot that might work better. So the plant looked slightly singed on the tips of 2 out of 10 leaves. I was thinking it was because it just jutted slightly out of the range of shade?

Would you be so kind as to diagnose my setup? Should I pick one compromise level of shade cloth that might work for all outdoor plants, using positioning. Or is it a better idea to have two or three different spots with different shade cloth levels?

There is no reference to southern California growing (except for what I have documented on my website from a bunch of years of trial and error) but you can come close with A Bay Area Guide to Orchids and their Culture by Mary Gerritsen, available from the San Francisco Orchid Society. The microclimates are well described so it is possible to extrapolate to southern California, and there is LOTS AND LOTS of good advice about what can be grown where. What makes it special is that the "whys" are well explained, so that you can extend the information to meet your situation.

---------- Post added at 05:10 PM ---------- Previous post was at 05:05 PM ----------

SEveral different spots, definitely. Different plants have different needs, And watch carefully. What works today may be too bright in a few weeks as we hit the equinox and beyond. I can only say that I have toasted more leaves in mid-March than any other time of year... sun suddenly clearing the house or a tree. Orchids can tolerate more light if moved gradually, but sudden changes can burn leaves in a few seconds or minutes. So keep a close watch as the sun shifts.