Archive for 6) The Indoor Habitat

O’ Tannenbaum, Selecting a Christmas Tree

 033   One of my favorite Christmas tree stories is from when I worked at the Seymour Botanical Conservatory in Tacoma.  A young, urban minister from one of the nearby churches came in around March to ask why his tree was dying.  After Christmas he had put it on his balcony and had been faithfully watering it.  Seeking more information, I asked him whether it was balled-and-burlapped or in a pot.  I had to stifle a guffaw when he told me it was in its stand!  The cut tree he had been nurturing for three months was essentially dead.  To give him some credit, it may have lived if it had been a willow!

An artificial tree can be chosen that is just the right size & shape.

An artificial tree can be chosen that is just the right size & shape.

   But today, which really is the “greenest” option, an artificial, cut, or living tree?  I admit to having owned an artificial tree (our son got over-eager one year and decided to put it up himself. He improperly, forcibly bent the branches down by mistake, basically ruining the tree for future use).  It was convenient, cheaper and was reused year after year.  (My husband would like to buy another, but I am resisting.) The problem is that artificial trees are not biodegradable and will eventually end up in a landfill.  Additionally, they are made of PVC plastic that may contain toxic chemicals. –Not what we want our children gathered ‘round.  Most are made in and shipped from China, adding to their carbon footprint.


A Natural Douglas Fir

A Natural Douglas Fir



   In contrast, cut trees are grown locally and can sequester a significant amount of carbon while they are growing–and they are renewable.  Some farms may use pesticides and chemical fertilizers. Perhaps you can find an organic tree farm; I have some I grew myself, but they are getting too big now, I may use the tops of the nonnative species sometime in the future. After the holidays, the tree can be recycled into mulch, returning to and improving the soil for other plants.

Picking out a Christmas Tree in Olympic National Forest

Picking out a Christmas Tree in Olympic National Forest

    Another option for a family outing is to head to our National Forests and find a “natural” tree to thin from our timberlands.  By issuing permits, the Forest Service controls the species, location, the quantity, and size of trees collected.  Basic permits are $5.00 in the Olympic National Forest and $10.00 in Mt.Baker-Snoqualmie National Forest.  Contact a ranger station for more information.

   If you bring a live tree inside, try to limit the time kept inside to less than a week.  Afterwards, keep it in a cool, well-lit area until outside temperatures are less frigid (in the 50’s)– do not allow the soil to dry out!  If it lives, it may become a treasured part of your landscape.

An older Noble Fir with cones

An older Noble Fir with cones

   My favorite species is the Noble Fir.  It is open and ornaments hang from it nicely.  Grand Fir has long, dark-green, flat needles.  California’s White Fir is similar, but has a bluish color.  The popular, Fraser Fir, from the southern Appalachians, is nicely pyramidal. All firs have a lovely, balsamy smell.

    Douglas Fir is so common here that many don’t appreciate it’s natural beauty.  It is often sheared to make a perfect pyramid, but an irregularly-shaped Douglas fir is often the “Charlie Brown” tree that is best loved!

Western White Pine

Western White Pine

   Those with allergies may prefer the less aromatic pines.  Western White Pine has soft, long needles with flexible branches. The more traditional Scotch Pine, with its stiffer branches and sharp needles can support heavier ornaments.

    Surprisingly, our native Sitka Spruce is sometimes used as a large, civic Christmas tree in the British Isles.  Live Colorado Blue Spruce should be avoided in the northwest due insect pest problems.  All the spruces are very prickly!

   Western Red Cedar branchlets are often used in garlands and wreaths for aromatic, festive decorations.

    As is appropriate, many other evergreen species of fir, pine, and spruce are used in other regions where they are native.  Even Eastern Red Cedar (a juniper) and the hybrid Leyland Cypress have graced holiday festivities.

    Whatever you choose, have a “Green” Holiday and enjoy decorating your beautiful tree with your family!


Keep Flowering Gift Plants Alive


A Christmas Cactus I have had for many years. To the left with the white flowers is an Oxalis, I received one year as "Shamrocks" on St. Patrick's Day.

A Christmas Cactus I have had for many years. To the left with the white flowers is an Oxalis, I received one year as “Shamrocks” on St. Patrick’s Day.

    Most potted plants sold in the florist industry seem to be destined for a short moment of glory before ending up in the compost pile. Plants such as Persian Violet, Exacum; Pocket book Plant, Calceolaria; Cineraria, Senecio sp.; and Ornamental Peppers are usually short-lived and best treated as annuals. Some flowering plants, however, can be kept alive and may bloom again if you know how to care for them. Many of these plants are forced to bloom for a particular holiday even though their natural bloom time may be in an entirely different season.

    Poinsettias can make an attractive houseplant throughout the year if kept in a bright place. To force back into bloom, they need at least 12 hours of complete darkness each night beginning in early October–even a small amount of red light will interrupt flower initiation. At the Point Defiance Greenhouses we were able to grow poinsettias without shading because there was no light pollution to interrupt the natural night period. Flowering Kalanchoe, similarly, needs 3-6 weeks of at least 14 hours of darkness.

    Christmas and Thanksgiving Cacti also benefit from 12 to 14 hours of darkness at night but are not as sensitive to light pollution. They do best when given cool night temperatures. I bring mine in from the greenhouse every year when it flowers.

I plant out forced bulbs later in the garden. I keep amaryllis in my greenhouse after they finish blooming.

I plant out forced bulbs later in the garden. I keep amaryllis in my greenhouse after they finish blooming.

   Many bulb species such as Tulip, Narcissus, Lily, Crocus, Hyacinth, and Iris can simply be planted outside later. You should keep them watered in a bright spot after the flowers have withered until the weather is mild enough to replant outside. Paper-Whites are not as hardy as other Narcissus but are zoned for the Puget Sound region. Although many flowering bulbs may eventually fade away, some, like Daffodils & Easter Lilies, consistently bloom every year in my garden.

    Giant Amaryllis, Hippeastrum sp., bears spectacular, large flowers. Just as for other bulbs, keep watering until leaves begin to fade; then let the plant dry out for a while. I bring mine back inside from the greenhouse whenever I see a new flower bud developing.

    Azaleas need to go through a seasonal temperature regime –warm for flower bud initiation –a cold dormancy period–a warm “spring” to bloom again. Two main hybrid groups of Azaleas are used for flower forcing. Non-hardy Southern Indica varieties must be kept in a cool greenhouse over winter. Kurume Hybrids may be planted outside in our area.  It may be worth a try to plant your azalea outside, but be prepared if it does not survive.

   Cyclamens like cooler temperatures and often wither quickly in a warm house. They are best given bright light in a cool room. Tubers go dormant in hot weather and may later grow and bloom again after several leaves have developed. Oxalis species, grown as shamrocks also benefit from a rest period.

   I predict that most of the expensive Orchids I see people purchase are doomed. Beginners may have some success with Cymbidium, Phalaenopsis, Oncidium or Paphiopedilum species.

   Hardy species of Primroses, Primula can be planted outside; non-hardy species, P. malacoides, P. obconica, & P. sinensus are best treated as annuals. Miniature Roses need to be kept on a bright windowsill or planted outside.

    Chrysanthemums come in many flower forms and colors. There are thousands of cultivated varieties. It’s worth a try to plant them out in the garden; however, some varieties may bloom too late for our climate.

Houseplants in the Healthy Indoor Habitat


Houseplants, left to right: Snake Plant, Banana Plant, Corn Plant (Draceana), 2 Peace Lilies and a Peperomia in back next to the window on the right.

Houseplants, left to right: Snake Plant, Banana Plant, Corn Plant (Draceana), 2 Peace Lilies and a Peperomia in back next to the window on the right.

   Much of my interest in horticulture began with indoor plants. I liked being surrounded by a jungle of tropical plants and enjoyed taking care of them. The fact that plants in the home or office help us to be healthier and happier has been shown by several scientific studies.

   Many of the materials used in the construction of our homes, offices and other indoor spaces contain toxic chemicals. Harmful chemicals also come in on our furnishings, computers, electronic devices, cleaners, and other everyday household products. Many of these chemicals volatilize into the air we breathe. These all contribute to what has become known as “sick building syndrome.” Indoor plants improve indoor air quality by actually removing many of these contaminants as well as airborne mold and bacteria.

   In addition to sequestering harmful volatile compounds, plants decrease carbon dioxide levels and increase oxygen & humidity levels, helping to reduce fatigue, colds, headaches, sore throats, coughs, nausea, sore & itchy eyes, dry skin, and loss of concentration. Plants can even help to prevent allergies by building tolerance levels and immunity to allergens. All these benefits help us get a more restful sleep, too.

   Plants that share our indoor space help our mental well-being. They help relieve stress, help us to be more productive, and just feel better all around.  Cheerful flowers make you calmer and more optimistic. And just the act of caring for a living thing can help when you are depressed and lonely.

   Indoor plants can muffle or absorb sounds, reducing distracting or annoying background noise. Plants with a lot of leaves such as Weeping Fig, Ficus benjamina, work best for noise reduction. Large indoor plants can also be used for screening.

   When I worked at the Seymour Conservatory, we would often get patrons wanting advice on houseplants.  A common one was: What can I grow with no light? My response to this query was: “try silk!” –Or– that if there is not enough light coming in from windows, supplemental lighting will be necessary.

   The other most common reason for failure in growing houseplants is infrequent watering or overwatering. Many people water regularly about once a week. I always recommend checking the dampness of the soil before adding more water. The best way is to stick your finger below the top layer of soil; sometimes you can tell by the color of the soil or the weight of the pot.

   The easiest “beginner” houseplant to grow is Snake Plant, Sansevieria trifasciata, also known as “Mother-in-law’s tongue.”  Also fairly easy is Spider Plant, Chlorophytum comosum, Peace Lilies, Spathiphyllum sp., Peperomia species, Dragon or Corn Plants, Dracaena sp., Swedish Ivy,  Plectranthus australis, and Wandering Jew, Tradescantia sp.

   Succulents, such as many species of cacti, can be easy to grow if you have a sunny south or west window. Donkey’s Tail, Sedum morganianum, and Jade Plant, Crassula argentea, are easy to grow succulents. I also always keep an Aloe vera growing to treat burns and other skin ailments.

   African Violets, Saintpaulia sp., brighten up my kitchen windowsill. The flowers are cheery and they bloom frequently.

   Although most houseplants are tropical in origin, Piggyback Plant, Tolmeia menziesii, is a Pacific Northwest native that can be grown as a houseplant.

   If you have small children or pets, it is a good idea to check on potential toxicity before you bring any plant into your home. The Humane Society has a good website to check on toxicity of each plant species: Dumb Canes, Dieffenbachia sp., are extremely toxic and are best avoided.

   A houseplant is a cheery gift for any occasion.

(This article was first published in the Peninsula Gateway on January 2012 as “Many benefits of indoor plants.”)