They're everywhere this year. Why are the needles on my pine trees turning brown or yellow? There's a thick carpet of discarded needles over the yard. Does this mean the end for my pine tree?
Not at all. In most cases, needle drop is a natural part of tree growth and maturity. Each year evergreens cast off twenty to thirty percent of needle growth. As the tree expands, its drop becomes larger--to be replaced with fresh growth in the spring.Newer needles should be at the end of the branch, and older (browning) needles at the crown. If primarily the tips of evergreen branch needles are brown, the culprit could be disease or insects. In that case, call an arborist for a consult.
Spruce trees hang onto their needles almost twice as long as pines--five to seven years as compared to two to four.
Needle drop can also signify the tree's reaction to weather patterns which took place during distant prior seasons. Beginning in 2014 there was a noticeable increase in yellow needle drop from white pines located in New England. The suspected cause was an extremely wet spring the year before, which may have infected new needles with fungal spores, resulting in the drop of needles in the second year. Most healthy trees 
will survive such an infection without intervention.Evidence of tip blight, cankers, or a purple cast to needles warrants a call to the local tree expert. Most of these diseases can be treated.
More serious is the white pine decline noted in the northeastern United States. This progressive decline is potentially attributable to warming trends.
Don't get the blower out! Fallen needles make an attractive mulch, and the price is right-- compliments of Mother Nature.
Here in the land of the giant conifer, a blanket of orange-gold needles hides all blemishes--just like a clean layer of snow.I don't remove fallen quills from flower beds until spring. They provide a layer of insulation for tender plants whose roots may be heaved to the surface and damaged by a "freeze and thaw" cycle. Partial decomposition sends healthy organic matter into the soil in early spring. As the weather begins to warm, rake away what remains
I reuse this natural mulch in areas that are not immediately adjacent to the house, around the base of trees, or as an alternative to woodchips for pathways. Its thick consistency is an effective barrier to weeds--and the needles cast a lovely scent when tread upon.Assuming your pine has healthy green tips and shows no sign of decline or disease, then the thick carpet of needles represents an ever-rotating parade of growth.
More on conifers:
Colorado Pine Beetle-Bad News Bugs
Witch's Broom -- What's That Spooky Bump on my Pine?
