What I mean is, I've noticed at greenhouses the plants are all jammed in side-by-side but they seem to be doing well. And in a number of the photos on this site, the ones especially showing people's lighting set ups, seem to have a lot of plants with pots touching side to side. If that works, then I can definitely fit my plants in well with a lighting arrangement (hoping to get some this fall). Just wasn't sure if it's bad to have them too close, not enough air, etc.

You're right, orchids too close together will create air movement issues, especially in enclosed areas like basements etc.

I guess if you had fans running then they could be grown closer to each other, not a bad idea if you want to fit more in.

Mine are very close but I always leave enough room around the pot to allow the foliage to spread out properly so the light gets to all the leaves and air circulates well around the pots. But then again I grow outside all year round and people who grow indoors probably have alternative culture than I would have here.

When are plants too crowded together? When they fall of the edge of the shelf!

:lol: :lol: :clap:

No problem when the plants are all the same size, but crowded plants of differents size are more problematic, small plants gets easily overlooked when watering and gets less light as well,

I try to leave a little bit of space between each of my plants, and as paphjoint said, I group them according to genera and pot size.

Uri is right. I crowd together plants of similar size and the ones that are in shorter pots--a problem with the smallest plants--I place them inside a taller pot or on something else to get them up to the level of the ones surrounding them.