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The truth about those ‘poisonous’ holiday houseplants

  • Author: Jeff Lowenfels
    | Alaska gardening
  • Updated: November 30, 2017
  • Published November 30, 2017

It would take a whole lot of bitter-tasting poinsettia leaves to harm a child or pet. But mistletoe and holly should be kept out of their reach. (Getty Images)

Ah, the winter solstice holidays! They feature a lot of indoor plants. What this means is this is a time of year to pay attention to sales and stock up on them. Many will carry over for years and years while others are to be treated like annuals. Either way, they lighten things up when we need it the most.

Here are a few questions I got this week about some of the traditional holiday plants.

First, every year during the holidays there are warnings about poisonous houseplants. Which are poisonous?

Usually these scare stories start to circulate at the appearance of poinsettia plants. These plants have been long plagued with the myth that they are extremely poisonous, especially to pets and children.

The myth has been traced to Hawaii, where in 1919 a 2-year-old child died of poisoning. Poor forensics fingered a poinsettia plant, and the breed has had problems ever since. The truth of the matter is that it would take some 500 poinsettia leaves (or their red bracts) to kill a child, and because they are so bitter that would never happen.

Similarly, you really don't have to worry about your pets. They won't like the taste of poinsettia if they are tempted to try it.

Mistletoe and holly, on the other hand, are more toxic. The former can cause a drop in blood pressure and problems breathing if enough is ingested. The leaves and berries of these plants should be kept out of the reach of children and pets. In fact, why have them at all if you are worried about accidental or curiosity-caused ingestion?

There are other decorative plants that you should keep out of the way of pets and children. These include amaryllis. Lillies are very bad for cats. Daffodils can be toxic to both dogs and cats. If you want a really interesting and long list of plant toxicity with regard to pets, check out It is an amazing list.

As an aside, of course, you should teach your children and your pets not to eat indoor plants. This may sound silly, but you teach them not to eat Christmas trees, which also happen to be mildly toxic, and it works, so you can do it with houseplants.

Finally, if you feel your child or pet has ingested a plant, you should immediately contact your doctor or the National Poison Center at 800-222-1222.

Next, every year I get questions about Christmas trees putting on new growth. Yes, it happens, because the tree is still able to find sugars and grow. No, the tree will not survive, develop roots and cannot be planted outdoors in the spring. Pretty quickly, these trees run out of stored nutrients and stop all activity.

OK, how about rooting new holiday cacti from existing plants? Several folks have mentioned that they have very old plants and want to know how to duplicate the feat. It is so easy. And, because these plants can survive for generations, a gifted plant given to a friend or family member can grow almost forever.

As noted, it is easy. First, fill a small pot with good soil or well-draining sand that includes some organic soil. To get the cutting, all you have to do is take one of the tip "leaves" or segments of the plant and gently twist it off from the mother plant. Them insert it into the soil of the pot, burying the bottom half, which will develop roots over the next three weeks or so. New growth will then appear at the tips of the cuttings. To get a nice looking display, take three cuttings and place each one in the same 4-inch pot.

Finally, even though I included amaryllis as one of the toxic plants, they do make terrific houseplants and are a great holiday gift to yourself or your friends. Nothing grows a bigger flower, and nothing is easier to grow than one of these bulbs. You will see them for sale all over town; buy them.

If you follow my instructions, you have had your amaryllis in storage for eight weeks and can take it out now and get it growing. If you didn't, and you have plants still growing, you need to put them into dormancy by withholding water and placing the plant in darkness for two months at a cool, 40-degree temperature.

Jeff's garden calendar

Poinsettias: These plants do not do well when allowed to dry and they hate drafts. Keep an eye on yours.

Lights: If you have had yours for a few years, you need to check your bulbs to make sure they are still putting out enough light. Google the brand to find out replacement times.

How to make herbal salves: 6-7 p.m. Wednesday, Dec. 13 at Alaska Botanical Garden. $40 for members and $45 for non-members; pre-registration is required. See for details.

How to make ice candles and luminaries: 12-1:30 p.m. Saturday, Dec. 16,  at Alaska Botanical Garden. $40 for members and $45 for non-members; pre-registration is required. See for details.

Also, three books that make great holiday gifts: "Teaming With Microbes," "Teaming With Nutrients" and "Teaming With Fungi"!

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