It’s a sad state of affairs for a horticulturist when her holiday houseplants get confused. Both my amaryllis and Christmas cactus were in glorious bloom two weeks before Thanksgiving.

In the old days, I’d take the easy way out. If my Christmas cactus was blooming the end of November, I’d call it a Thanksgiving cactus. The two are closely related, but it’s still poor form for someone who knows they’re different species. To tell them apart, look at the flattened stem segments. The Thanksgiving cactus has saw-toothed projections along the margins. Those of the Christmas cactus are more rounded.

No matter the name, both species respond to changes in light and temperature in the great Alaska indoors. Flower buds are initiated as the length of the night reaches about 14 hours and temperatures drop to between 60 and 65 degrees. You can regulate flowering time by adjusting either one of these parameters. If grown cooler, in a room between 50 and 60 degrees, plants will likely flower even if you flip the lights on during their dark period.

If you shiver at the thought of keeping the house below 65 degrees, you can still get your Christmas or Thanksgiving cactus to bloom. Make sure it gets bright light during the day but has a period of 12 to 16 hours of uninterrupted darkness until you see those little flower buds poking out of the ends of the stems. If you’re not seeing buds yet, push the plant closer to the window and put a paper bag over it each night when you go to bed.

Or forget fussing with the Christmas cactus and brighten up the house for the holidays with a poinsettia. Poinsettias are the perfect holiday houseplant. They are disposable. If you don’t have room for more houseplants, or not enough light for anything living to thrive, you can toss out the poinsettia when you take down your tree. Support the horticulture industry by planning to purchase another poinsettia next year. Most poinsettias sold in Alaska are produced in the state, by Mosesian Farms in Anchorage, but I remember the days when Lee Risse grew poinsettias for his Fairbanks customers.

Poinsettias should not be eaten, but are not considered poisonous. It’s the holly berries and mistletoe berries you need to make sure the kids don’t pop into their mouths. Did you know that mistletoe can be found on hemlocks in Southeast Alaska and that at one time, Christmas trees were grown in Nenana?

Last Christmas, I had two trees. Right after Thanksgiving, I usually make the rounds to find out what kinds of trees will be available so that I can expound upon their virtues. Trees vary in branch strength and spacing, fragrance and needle retention. Because of the boom and bust nature of Christmas tree sales, the same species are not available every year. Last year Nordmann fir reigned supreme at the annual Kiwanis Club of Fairbanks tree sale at the fairgrounds.

I rolled into the sale right before closing but the volunteer staff was more than accommodating. They even shrink-wrapped a boy to demonstrate how I would be able to get a tree home without having needles drop all over my car. I was planning to cut down a tree from the yard but what could I do? I had to buy a tree and so I did.

I also cut down a white spruce. Granted, our native spruce don’t have a sheared form but I am from the era of real tinsel. I like a Christmas tree with enough space between branches to dangle ornaments. Some of the commercial firs hold on to their needles even after they’ve turned brown and have been set outside for the chickadees to use as cover as they flit about. If my Christmas tree held its needles until Easter, I might be tempted to decorate it with eggs.

White spruce do hold their needles longer than black spruce, according to a UAF study published as “Caring for Black or White Spruce Christmas Trees,” Miscellaneous publication 88-3. If you’d like to cut down your own tree and don’t have a woods that needs thinning, check out the Fairbanks Daily News-Miner article that ran on Nov. 29, which is available at bit.ly/2Lh5Rzl. It covers everything you need to know about cutting a tree on state land.

Julie Riley is horticulture agent for the UAF Cooperative Extension Service Tanana District. The publication on Christmas tree care mentioned above can be found at bit.ly/35T8KhM or among the long row of free publications in the hallway outside her office in the University Park Building, 1000 University Ave., Room 109. As has been traditional for many years, university offices will be closed between Christmas and New Year’s. The Tanana District office will close Dec. 23 and reopen Jan. 6.