URI expert answers top questions on Christmas tree care

KINGSTON, R.I. — December 6, 2004 — With the holiday decorating season in full swing, the most frequently asked questions on the University of Rhode Island’s gardening hotline are those relating to Christmas tree care.

The following are the most common questions and their answers, provided by Rosanne Sherry, coordinator of the URI Master Gardener Program who oversees the hotline:

Why are the needles on my tree falling off?

According to Sherry, it’s vital that cut Christmas trees are well watered to prevent them from prematurely dropping their needles. A healthy tree will soak up one to two gallons of water per day, depending on the size, so it should be checked daily to see if more water should be added.

“It’s also important that, before you put the tree up, you cut off an inch or two from the bottom of the trunk to expose new tissue to absorb the water,” Sherry said. “Without new tissue exposed, it can’t soak up any water.”

Needles may also drop prematurely from Christmas trees if the tree grower cut it too early in the season, or if it was an unhealthy tree to begin with. Sherry said that fir trees, while more expensive, typically hold their needles longer than pine trees.

Why are there bugs coming from my tree?

Sometimes ladybugs, flea beetles, conifer seed bugs and other insects hibernate or lay their eggs on trees destined for the Christmas tree market. When the tree is brought inside and the insects warm up, Sherry says the bugs “think it’s May or June and time to emerge.”

While it’s nearly impossible to know if a tree has insect eggs or larvae on it when it is purchased, Sherry notes that bugs are more likely to emerge on trees that were cut locally or on trees that have been inside for a long period of time.

She recommends simply vacuuming up the insects as they are found or spraying an insecticidal soap on the tree to kill them. Do not spray the tree if it already has electric lights on it, as the spray may cause an electrical short circuit and start a fire.

What’s the best thing to do with my tree after the holidays?

Sherry said there are a wide variety of environmentally appropriate options for disposing of your Christmas tree. Many municipalities collect trees left out with the trash and shred them for later use as mulch or compost.

Some coastal communities collect them and use them to help stabilize the dunes at local beaches. She recommends checking with your town to see if it collects discarded Christmas trees.

For residents with perennial gardens, Sherry suggests cutting off the boughs of old trees and spreading them on the garden beds to protect dormant plants from snow and ice accumulating through the winter months.

Discarded Christmas trees can also be set outside near bird feeders to serve as a windbreak and hiding place for birds when they are feeding.

How do I take care of a live tree?

Live trees are a challenge because their root ball must be maintained while in the house, and then the tree must be planted during the coldest time of the year.

According to Sherry, before even purchasing a live tree, dig the hole it will later be planted in before the ground freezes, cover the hole so it doesn’t fill with snow, and protect the soil from freezing by covering it with a tarp or bringing it in a shed or garage.

The key to ensuring that the tree will survive after being planted, Sherry said, is to keep it indoors for only seven days, and to place it in a cool location like a breezeway or unheated sunroom. If it is indoors longer than a week, the tree will acclimate to the warm indoor temperatures and then be shocked when it is returned outside after the holidays.

Sherry said it’s especially important to measure the tree to fit your space, remembering to keep in mind the depth of the root ball and that the top of the tree should not be trimmed. Cutting the top off will stunt any further growth after it is planted outside.

With the root ball attached, Sherry said a live tree is going to be heavy – probably more than 100 pounds – and it will be messy and wet. So she recommends standing the tree up in a big plastic or galvanized tub. “You won’t need to water it much, just an occasional spritz of water when the burlap around the root ball gets dry,” she said.

After the holidays and within seven days of bringing the tree inside, plant the tree as soon as possible in the pre-dug hole. Add a little mulch and water, and cover the root ball with the protected soil from the hole. If the weather or other circumstances make it impossible to plant the tree immediately, put it in a cold shed or garage to keep it cool until it can be planted.

“Don’t let a live tree know it’s been indoors,” Sherry said, “so keep it inside as short as possible.”

For more information on this and other gardening questions, go to the URI Master Gardener website at www.urimga.org.