Different light needs?

[RoseSD]

I have eight 2 years old catt seedlings that all started going "eyes" in wake to our "early Spring". I also have six mature Catt but many are still asleep. They all sleep indoors but I take them out to the 75% shaded outdoors table during the day.

My question is, do seedling size plants (in 2 or 3 inch pots) require more or less length of outdoor light exposure? I water the smaller pots more frequently for sure.

[Dimples]

The general trend in plants is that seedlings do best with less light than adult plants. For example, if an adult plant of species-X needs full sun, the seedlings will grow well under 30% shade cloth until they're large enough to tolerate full sun. Hopefully, some Catt. growers will chime in with specifics for you and your setup.

Edit: reread your question and noticed it was about light length/duration, not intensity. Sorry.

[Ray]

Established seedlings and mature catts have always gotten the same conditions under my care.

I don't know if that's "right" or "wrong", but they're all growing in close proximity in the wild, aren't they?

[Dimples]

Ray - they would be growing in similar conditions in the wild, but the successfully established seedlings of most plants will be growing under or next to larger plants present in the habitat, so may not receive the same light intensity as the parent plant until they get older/bigger and are no longer shaded by the surrounding plants. Again, this is a generalization for all plants, and I don’t yet grow orchid seedlings so I don’t know what size = able to tolerate adult conditions.

Plants in human cultivation usually get pampered compared to wild plants, so it may be a moot point. 75% shade cloth is pretty shady so I’d expect it would be difficult to give any plant too much/intense light in those conditions.

[Roberta]

I would give them all the same duration of light Yes, a little less intensity for the seedlings... Now that spring is approaching, consider starting to acclimate them to more light (gradually) 75% is pretty dark for a Catt. As for the larger ones being "asleep", Catts don't have dormancy. But they have different seasons for both growing and rooting, which is why you have to observe them.

We have had some cold nights recently, but within a couple of weeks, nights should be warm enough to start moving things outside. Best to acclimate things slowly.. light especially can increase suddenly this time of year (leading to toasted leaves if they aren't adjusted gradually)

[isurus79]

I grow my seedlings next to my adult Cattleyas and they receive the same amount of light for the same duration.

I'll also add that 75% shade cloth is pretty dark, especially this time of year. What part of the country are you growing in?

[Roberta]

Originally Posted by isurus79

I grow my seedlings next to my adult Cattleyas and they receive the same amount of light for the same duration.

I'll also add that 75% shade cloth is pretty dark, especially this time of year. What part of the country are you growing in?

RoseSD is in the San Diego area I am not far away.. that is why I use my environment as a pretty good approximation for hers as a reference point. Where I live, 75% is barely adequate for Paphs. Hence my additional suggestion... start acclimating the Catts to higher light NOW - we do get some clouds, sun is not that intense, After the equinox the sun starts to clear buildings and trees suddenly, it's the time of year where I have toasted more leaves than any other ... time to avoid surprises. Forecasts have nights near or above 50 deg F (10 deg C) within the next week, and going forward. Wouldn't move the Phals out for another month or two but practically everything else is a candidate.

[Ray]

Originally Posted by Dimples

Ray - they would be growing in similar conditions in the wild, but the successfully established seedlings of most plants will be growing under or next to larger plants present in the habitat, so may not receive the same light intensity as the parent plant until they get older/bigger and are no longer shaded by the surrounding plants.

Possibly, but if you consider the dust-like qualities of orchid seed, who's to say where they end up!

[estación seca]

Seedlings are at much higher risk of severe damage from sunburn than are adults, so I give them less light. Sunburn is a real problem here in Phoenix, and I would think San Diego too. Catts grow well with less light but they don't flower well. Seedlings aren't going to flower so I prioritize preventing sunburn.

[Roberta]

If "two years old seedlings" mean 2 years in the possession of the OP, they're not babies anymore.
So it also depends on how well established they actually are. 2 years out of flask is still fairly young, but 2 years after purchase add another year or two to their actual age and they aren't really "seedlings". That isn't clear from the post.