Pine shedding needles could have multiple causes
Q: All of a sudden my pine tree is shedding lots of brown needles. Is it sick? — O.T., Albuquerque
A: Your pine tree might be and might not be sick. Gather a collection of the needles your tree has dropped and give them a close-up visual inspection. Are there wee small black dots attached to the needles? If so, those wee dots are a bug called scale, or at least the house they used and are now living in elsewhere in and around the tree.
So inspect the tree itself for yet more black dots on the green needles worn by the tree. If you notice more black dots on green viable growth you should treat your pine for scale. Several timed applications of horticultural grade oil (Volck, the name brand from Ortho, or dormant oil) will help to control these pests.
While you are doing the visual inspections of the tree look for clusters of smallwinged black creatures. Those are aphids and are happily sucking the life out of the tree, perhaps contributing to the tree dropping needles. Also, when you have aphid infestations, plant life is more prone to a fungal disease called “sooty mold” and that in itself might explain the needle drop. The oil treatment will help eradicate those pesky aphids and help address any sooty mold issues also, so it’d be a threefold, safe treatment to get your tree healthy again.
While I’m at it I want to address the watering of your tree. Now stand up, and extend your arms out from your body so you are shaped like a cross. OK, point just your fingers downward. You have just mimicked a drip line. If you were a tree, the place where your fingers are pointing is where your feeder roots would be below ground.
So if you are watering just near your feet — or the trunk of the tree — the tree’s feeder roots could be suffering, not picking up the water the tree needs and in a fit of selfpreservation the tree might be casting excess needles so it has less to take care of. That’s not a good thing, so monitor how the tree is being watered and correct any issues to better tend the tree.
The good news is your tree could be acting naturally. You know how when you brush your hair some ends up in the brush? Or periodically trim your fingernails to keep them tended. Well, pine trees do shed older needles and that’s natural.
The needles can be aged by their placement on the tree branch. At the tip you’ll notice fresh tender new growth. Just behind that “newness” notice the older (last year’s growth) needles. They look stouter and are usually a deeper shade of green. Then behind them are the three-season needles. Essentially, the tree is done with them. They don’t get as much sunlight so they don’t create food for the tree so why keep them? They have served their purpose so they just get shed. It’s the way of a pine. That’s not a problem at all.
So that’s what I’d have you look for to check on the status of your tree. Black dots, winged bugs or a sooty mold on your tree means a treatment. Not finding any critters, then just rake up the cast needles, keep your tree adequately watered and know that it’s doing OK.
Need tips on growing your garden? Tracey Fitzgibbon is a certified nurseryman. Send your gardenrelated questions to Digging In, Rio West, P.O. Drawer J, Albuquerque, NM 87103.