Sites

Ask the Gardener: How to keep your Christmas tree from losing needles

Ask the Expert Gardening
Christmas-Tree-Lot
Christmas trees can drink a gallon of water a day. Debee Tlumacki for The Boston Globe/File 2014

What to do this week: Cut or purchase greens and a Christmas tree for decorating. You should prune the evergreen trees and shrubs in your yard now so you can recycle the cuttings for holiday projects. Cuttings with needles stay green longer than broad-leaved evergreens. Prune evergreens back to a crotch in the bough so you don’t leave a stub. Don’t use spruce, balsam, holly, or white pine indoors unless the stems are in water. Arborvitae, chamaecyparis, boxwood, and mountain laurel don’t require water to stay fresh indoors. Many needled evergreens will last a long time in outdoor wreaths and planters without water. Mist wreaths to help keep them fresh.

 

Q. Last year my live Christmas trees lost their needles. What can I do to prevent that from happening again?

M.M., Groton

A. Christmas trees can drink a gallon of water a day, so survival can be all about the size of the tree stand reservoir. If the water evaporates after the tree is set up and decorated, your Christmas tree is toast, even if you refill the stand later. No do-overs! So buy a reservoir that holds at least 2 gallons. If you are already stuck with a puny one and don’t want to fill it twice a day, you can try attaching an automatic tree-watering system that will keep it topped off, like the ingenious Elf Logic, which costs about $20 and looks like a hospital IV bag that you hang on your tree (hopefully in the back).

 

Q. The leaves on my hydrangeas are limp and soggy and not falling off. Do I need to clip them one by one?

LINDA PALMER, Milton

A. Your hydrangeas did not have a transition period to get ready for winter. Instead of losing their chlorophyll, drying out, and dropping as the nights grew colder, many leaves stayed green and vibrant through a weirdly warm fall free of frost until a couple of weeks ago. Then overnight temperatures plummeted into the teens, zapping all of the moisture in those still verdant hydrangea leaves and turning them into green slime. Don’t clip them, because you could accidentally trim off the buds for next year’s flowers. The good news: The leaves will eventually drop without your help.

Send questions and comments, along with your name/initials and community to stockergarden@gmail.com. Subscribe to our newsletter at pages.email.bostonglobe.com/AddressSignUp.