Christmas disease

They can last for years, if you choose the right ones and give them good care

Watching a Santa Ana wind desiccate a lot full of cut Christmas trees in Southern California one weekend, I was struck by how quickly the sawed-off trees dried out, their needles turning as crisp as toast before falling off. By comparison, trees in containers use nature's perfect hydration system - roots embedded in soil - to keep their foliage fresh. That's one reason living Christmas trees remain so popular.

Which trees perform best during their stay in containers and later in the garden? Which ones were favorites for decorating? To find out, we queried Sunset readers and surveyed nurseries around the West. Colorado blue spruce (shown at right) won the popularity contest, followed by an assortment of other conifers (see page 56).

We also learned that people who grow living Christmas trees become very attached to them: they coddle them, play dress-up with them at Christmas, and usually move them to a place of honor in their gardens when the plants outgrow their containers and get too big to bring into the house.

BE A SMART TREE SHOPPER

Pick a conifer that's as well suited to your taste in garden plants as to your taste in Christmas trees. You can expect to use the same tree in a container for four to seven years, depending on how fast it grows. If you intend to plant it outdoors eventually, be sure the variety is one that thrives in your climate.

The nursery industry offers conifers in two basic grades: sheared, well-tapered trees grown for sale as living Christmas trees; and landscape-grade trees that receive no special care. You may not find both grades at every nursery, but when you do you'll notice a marked difference in quality and price between trees of the same species and size. Landscape-grade trees can be rangy, but they cost about a third less than sheared trees. In the long run, the two grades will perform about the same in gardens. Trees of both grades are sold in various sizes in 5-, 7-, and 15-gallon plastic cans.

As you shop, you also may see trees tagged with the logo of Global ReLeaf, a tree-planting program sponsored by American Forests, the nation's oldest conservation organization. Global ReLeaf encourages you to plant your tree outdoors after the holidays. For information on how you can plant your tree to save energy, visit the American Forests Web site at www.amfor.org.

WESTERN CONIFERS

Coast redwoods and giant sequoias are close relatives. Redwoods are greener and not as wide at the base as sequoias; they thrive along the coast and won't take extreme cold.

Sequoias grow more slowly than redwoods, and their foliage is a grayer shade of green. These trees do best in the Pacific Northwest, mountains, and colder interior climates.

Colorado spruces have stiff branches bristling with needles in shades from bluish green to steely blue. 'Glauca' is the classic Colorado blue spruce, but its close cousin 'Hoopsii' has superior blue color and good form even when small, making it an ideal living Christmas tree.

Deodar cedar is one of the most graceful trees anywhere. Gigantic, lighted specimens line Christmas Tree Lane (Santa Rosa Ave.) in Altadena, California.

Douglas fir carpets the Pacific Northwest and grows wild down into Northern California and east to the Rockies. You can keep a Douglas fir dense and symmetrical in a container for many years using hedge shears.

Firs are classic cut trees; short-needled, well branched, and well formed, they fit everybody's mental image of a good tree. Some make outstanding living Christmas trees, but others are less than perfect as container plants: noble fir, for instance, is one of the most popular cut trees, but it has a hard time surviving in a nursery container.

Grand, noble, and white firs often don't do well when transplanted from field to pot, but more fibrous-rooted firs like alpine, balsam, cork, and Fraser handle transplanting better.

To determine if a fir is container- or field-grown stock, ask the nursery staff or check for yourself by digging gently through the surface layer of potting soil to the rootball. If the rootball is covered with burlap, or if you find the roots growing in soil that's markedly different from the soil on the surface, the tree is field grown. If you find the same kind of soil throughout the pot, it's container grown.

Pines usually have longer needles than firs, and they often have a more open form. Most pines thrive in hotter, drier climates than firs and spruces.

Many nurseries still sell Monterey pine (Pinus radiata) as a living Christmas tree; if you buy one, keep it in a container and prune the roots annually to keep growth under control. Sadly, Monterey pine is no longer a viable choice as a landscape plant in California because the species is vulnerable to pitch canker, a fungal disease that has killed thousands of the trees in recent years.

For a chart of good living Christmas trees for the West, see page 56.

Quick as a flash: A nursery pot cover-up

Need an easy cover-up for your living Christmas tree? You can make an elegant, yet simple, one by wrapping the container in aluminum flashing, as shown at right, around the base of a Colorado spruce. Available at hardware stores in silver or gold, flashing is sold by the foot and ranges in width from 8 inches (70 cents) to 20 inches ($2). Living Christmas trees are mostly sold in 5- to 15-gallon containers. Cut the aluminum to fit the size of your container and secure it at the back with silver duct tape. Shiny metallic flashing adds a festive touch, is easily removed, and can be safely stored for future use. For other ways to dress up a nursery container, see page 104.

How to keep trees healthy

INDOORS

* Keep the tree in its original nursery container at least for the first Christmas. You don't want to add the shock of transplanting to the stress of its indoor stay.

* Display the tree indoors for no longer than 10 days. Keep it away from heater vents and fireplaces.

* Decorate with small, cool bulbs.

* Water regularly. One easy way: Dump two trays of ice cubes onto the soil surface daily. As the ice melts, the water trickles slowly down through the root zone.

* In cold-winter areas, before you even bring the tree into the house - and before the ground freezes - dig a planting hole in the garden (the hole should be slightly larger than the container). After its indoor stay, ease the tree's transition from the house to outdoors: First place it on a cool, bright porch for a few days; then move it to a protected place outside where the rootball won't freeze; finally, plant the tree, container and all, in the hole you dug. Spread a 5-inch layer of straw mulch over the top of the rootball to protect roots against freezing weather.

AFTER CHRISTMAS

* Water the tree regularly year-round. Trees in containers are much more vulnerable to drying out than trees in the ground, so check often by sticking a finger in the soil; if the top 2 inches of soil are dry, it's time to water. Always provide enough water so a little trickles out the drain holes.

* When new growth starts in spring, feed the tree with controlled-release fertilizer (a formula that releases nutrients over a six- to nine-month period is a good choice).

* Each spring, before new growth starts, gently slide the tree partway out of the pot and check the roots. When they begin to circle the inside of the pot, nip them back with pruning shears, rough up the rootball, and move the tree into a larger pot.

Best living Christmas trees for the West

Afghan pine Pinus eldarica

Also sold as Goldwater or Mondell pine, this fast-growing tree has an open habit and long needles. Good choice for desert gardens.

* Sunset climate zones: 7-9, 11-24

* Height: 30-80 ft.

Aleppo pine Pinus halepensis

Fast-growing tree with light green needles. Well suited for the low desert. Susceptible to dieback in Tucson and mites in Southern California.

* Sunset zones: 8-9, 11-24

* Height: 30-60 ft.

Alpine fir Abies lasiocarpa

Slow-growing tree with bluish green needles. A. I. arizonica, which grows in the same areas, has blue-gray needles and creamy white, corky bark.

* Sunset zones: 1-9, 14-17

* Height: 60-90 ft.

Coast redwood Sequoia sempervirens

Feathery leaves are green on top, grayish underneath. Relatively pest-free true, as long as it gets enough water. A big seller in Southern California nurseries.

* Sunset zones: 4-9, 14-24

* Height: 70-90 ft.

Deodar cedar Cedrus deodara

Nodding branches bear green needles with a bluish, gray, or golden yellow cast. Floppy top makes it hard to mount a star atop the true. A good garden tree if you have room.

* Sunset zones: 2-12, 14-24

* Height: 80 ft.

Douglas fir Pseudotsuga menziesii

Soft dark green or blue-green needles. Easy to grow and shape by shearing. P. m. glauca is a hardy form in the Rockies. A handsome Christmas tree.

* Sunset zones: 1-10, 14-17

* Height: 70 ft.

Giant sequoia Sequoiadendron giganteum

Dense gray-green foliage; red bark. Widely adapted; able to tolerate colder, drier climates than coast redwood. Potentially huge tree.

* Sunset zones: All zones

* Height: 80 ft.

Korean fir Abies koreana

Pyramidal tree with short, shiny green needles. Good choice for Southern California. Slow-growing, compact (seldom taller than 30 ft.).

* Sunset zones: 3-9, 14-24

* Height: 10-30 ft.

White fir Abies concolor

Symmetrical tree with bluish green needles. A. c. 'Candicans' has bright silvery blue needles. Good container plant.

* Sunset zones: 1-9, 14-24

* Height: 30 if. (eventual height when planted in the ground)

COPYRIGHT 1998 Sunset Publishing Corp.
COPYRIGHT 2000 Gale Group