I think that's the million dollar question. ;)

You should see mine. thats not as bad as mine. I had my seedlings in my greenhouse at work. I finally lost the "runt". my other one was looking sad so i brought him home and he sits under my shed overhang next to some other varieties. the new leaves are looking better and i am seeing another shoot off of the main original shoot so i think he is happier. From discussions in here. the seedlings like filtered sun or shade....now mine is sitting in almost complete shade....its open but no direct sun beating on it. This is just what is happening to mine and what i'm doing to try and fix my problem. I'm also watering it but not drenching it. Hopefully Roger might chime in and give us his expert opinion....i believe he is the guru on moso seedlings....

Kurt

Down here in San Antonio TX, I have a lot of yellow/brown tips on several species of Ph. These are temperate bamboos that I suspect are maybe not totally comfortable in 95F heat and boiling sun for weeks and weeks, even with watering every 2 days. True for both container and ground-planted Ph. No matter how much I water my Ph. nigra "Folsom black"/daikokichiku, its leaves curl in the mid-afternoon baking.

My Bambusa tuldoides, a tropical bamboo, looks fantastic, no brown tips, and is putting up 20 ft culms 14 months after planting.

I wouldn't worry about brown tips, but would worry leaves fully yellow/brown. Seedlings of course are less robust.

I have noticed that the more room I gave my seedlings, regardless of whether it appeared they needed the room or not, the less leaf burn I had. I agree with Kurt that your leaf burn does not look bad at all. I had some that were so awful the leaves died. The only thing that kept them alive were the new constant growth. The ones that did not put new leaves out fast enough DID NOT make it. So my only suggestion, although it may just be a chance observation, is to repot them to larger-than-you-think-necessary pots.

The leaf tips stay wet the longest and may have more fungal problems as a result. Better air circulation may help. Just a guess.

hello
i would think imho that wash dc is a fairly good area for moso to grow as you get muggy summer heat..young moso dislike heavy sun for the first few years till they harden up..id not worry about what you have shown us...us less they get totaly brown and then the rhizomes may still be alive...i planted mine in feb and all 3 moso plants the leaves turned brown ,yet they sent up new culms within 2 months of planting..they have double there culms and have reached the hieght of the orgnul plant and mine are in full sun at 2,500 feet.my plants came from LA.and where grown from seed and i planted then in year 2-3 of there life...if you love moso as i do you gotta see the famious moso grove in the old anderson cematary in anderson ,sc...i use a picture of that on my groups front page....i will be planting anderson moso this year as its the most hardy of all moso's

Here is a link that might be useful: east coast bamboo group