Light and size/shape of leaves

[Becca]

I have a question in regards to the relation of adequate lighting and the size and shape of leaves for orchids such as a Paph or a Phal. Yes I realize they are two completely different kinds of orchids, but with a couple of each that I have, I have noticed some of the leaves on them looking long and not very wide. I am trying to figure out if this is due inadequate lighting or what? One is a Paph. Vanda M Pearman I have noticed this on the new growth and the others are a few of NOID seedling phals. Any advice would be appreciated! Thanks!

[Ray]

In many cases, that's more of a genetic- than cultural thing, although good overall culture (not just light levels) will often lead to fuller, larger foliage, as well as more leaves.

Yes, low light levels can lead to "leggy" growth, but that tends to be reflected in greater distances between leaves, not necessarily elongated leaves.

[Tindomul]

I've heard that Phals will respond to higher light levels by growing wider, rounder leaves, and grow longer narrower leaves in lower light levels.

But I think that Ray's explanation makes a bit more sense.

[Becca]

Originally Posted by Ray

In many cases, that's more of a genetic- than cultural thing, although good overall culture (not just light levels) will often lead to fuller, larger foliage, as well as more leaves.

Yes, low light levels can lead to "leggy" growth, but that tends to be reflected in greater distances between leaves, not necessarily elongated leaves.

That makes sense to me as well, but.....the Paph. I mentioned earlier had wider or I should say rounder leaves on it's original growth, I received it with a second growth and each new leaf seems to be getting narrower or not as round so I just wanted to make sure I wasn't depriving it of needed light. I did move it from the floor of my orchidarium up to the next level, so I will wait and see what the next leaf looks like, it is to small to tell at this point!

[Ray]

Tindo, that was my understanding too, but I've seen too many flats of phals with both types of leaves on sibling plants grown identically.

Like most things, the correct answer is probably "all of the above".

[goodgollymissmolly]

I think Ray is correct that it's a little of a lot of stuff. I wonder about the comment that in high light the leaves are wider (rounder) than in low light. That comment (in my mind) creates the impression of higher leaf area in higher light. I think that is backwards.

I understand the concept of the plant "reaching" for light in low light situations. However that usually results in longer stems rather than longer leaves. My gut feel is that leaves are smaller,plants are more compact, and spikes are shorter as light levels increase.

[Undergrounder]

I've seen in my Paph seedlings that the leaves grown in flask under high artificial light are fat, the newest leaves grown under my less than ideal lighting setup are generally thinner and longer.

[Tindomul]

Originally Posted by goodgollymissmolly

My gut feel is that leaves are smaller,plants are more compact, and spikes are shorter as light levels increase.

That could help explain why my Phal, Baldan's Kaleidoscope is giving my such short spikes, though many of them.

[Brooke]

Orchid specialists who breed and show their plants keep them in fairly low light to create bigger leaves, taller spikes, more intense color on the blooms, bigger blooms and exaggerated distances between the blooms for great spacing of the buds (no overlapped blooms).

A plant grown in the shade will always have bigger, more erect leaves. They need the surface area to gather the energy to grow. The same plant grown in full sun will have more compact leaves and actually be shorter than their shade grown brother.

Brooke

[Ross]

This may be true as a generality, but I agree with Ray, in that certain spp show certain tendencies, like small leaves or large leaves. I have two seperate Phal crosses, one has giant leaves (12-14") and one has really smallish leaves (6-8") and they sit nearly next to one another under same lighting. The big leaf orchid had big leaves when I purchased it, and after two seasons, is still growing 2 new big leaves, same size as original, each season and blooming reliably. The other was from a keiki of a plant with smallish leaves (6-8") and still grows small leaves. So I wouldn't be so inclined to believe light has all that much to do with it. Might be true for certain plants, but not always.