What to do this week: When decorating with evergreens, avoid using tinsel and other materials that will hamper recycling them later. After the holidays, remove all the decorations from your tree and set it out as cover near your bird feeder, or cut off the boughs and lay them on your perennial garden as a layer of winter mulch. Don’t burn Christmas trees in your fireplace. They can ignite creosote deposits in the chimney, and the sap can explode.
Wait until just before Christmas to bring a potted living tree indoors that you want to plant outdoors later. Dig the planting hole in your yard ahead of time.
You can pamper houseplants (and discourage spider mites) by setting a humidifier near them, spraying them with a mister, or even giving them a lukewarm shower. Houseplants help remove indoor air pollution from household chemicals. An unblocked south- or west-facing window helps the largest variety of plants grow. If you lack window space, full-spectrum fluorescent lights are a decent substitute for daylight.
Q. I like the smell of live Christmas trees. Which kind smells best and lasts longest?
A. I think the best-smelling species that hold their needles well are balsam and Fraser firs and Scotch pines. Any kind of tree (except hemlock) will last longer if you cut your own, which also supports local farming. Don’t buy a tree that is already shedding a lot of needles. Check by tapping the trunk butt on the ground before you buy. Also, the boughs of a fresh tree will bend instead of break. Have the nursery retrim the butt or do it yourself when you get home so you have a fresh cut. Immediately prop it up outside in a bucket of warm water to hydrate. If you are not ready to decorate, store it outdoors. Bring it inside on a day when temperatures are over 45 degrees or in two stages, with an overnight spent in a heated garage to lessen the shock of temperature change.
Q. I got paperwhite daffodil (narcissi) bulbs as a gift. Now what do I do with them?
A. Wash pea-sized pebbles, then use them to fill the bottom of a wide bowl 3 inches deep. Set the bulbs on top, pointy end up and not touching one another, and then fill the bowl with water so it is barely touching the bottom of the bulbs. Put them in a sunny window and keep the water at that level. They will grow roots in the anchoring pebbles and bloom in a few months. They’re very fragrant. Tie them to a woody stem used as a stake if the leaves want to tip over, and discard them after blooming. The more light you give them, the more compact they will grow.
Q. My wife started ripping down the beautiful ivy that has been growing on our old brick Colonial. I like the way the ivy looks and would rather keep it. She says it’s bad for the house. I said, “People spend a lot of money sending their kids to fancy schools that are covered in ivy, so it can’t be that bad, and besides. I bet some crappy schools plant ivy to make people think that their schools are better than they really are.’’ So what’s the deal with ivy? Good or bad?
GENE RAINVILLE, Andover
A. Ivy is not good for masonry. Ivy League schools have actually spent a lot of money to remove these vines from old brick buildings. They were covered with it simply because once it was planted, it was very difficult to get rid of. So don’t worry. Your ivy will grow back from the roots, but do you really want it to?
Hip hip hooray for the second edition of “Garden Insects of North America: The Ultimate Guide to Backyard Bugs’’ by Whitney Cranshaw and David Shetlar (Princeton, $35). I have spent hours scanning the 3,300 color photographs, looking for creatures I recognize from my own back yard — from monarch butterflies to milkweed longhorns. It’s a definitive guide to the miniature world of strange creatures that pollinate and patrol my garden, rewarding close observation.
Note to readers: This will be my last Ask the Gardener column before my winter hiatus, but keep sending questions. I’ll see you in the spring.