clones have brown on very top? anyone seen this before

Some of my new clones have brown at the very top of the nodes. The plant looks heathly and green all over but the very top of the nod is brown or a brownish red? Anyone got any ideas?

how are you going to ask if anyone has seen this before and you dont even post pics.





edit: oh and welcome to RIU.

looking for some general help. ill post pics if the problem gets worse

have you tried the plant problems thread? besides you will get better assistance with pics. they take away alot of the off the wall bs suggestions you'll get. besides you havn't told anything about your grow.
hydro/soiless/dirt? nutes? lighting? temps? its all in the details.

Do you have them under a humidity dome??

how close are they to the lights?