
Trees breathe, like we do, but in a different way. Their leaves take in carbon dioxide, water and the sun’s energy, and turn it into sugars that feed the tree. Known as photosynthesis, the process emits vital, life-giving oxygen. Trees’ ability to removal carbon from the atmosphere — and store it in their wood — helps us mitigate the effects of climate chaos: In just one year, a mature tree can absorb half a metric ton of carbon dioxide equivalent. Trees are also essential since they remove air pollutants, prevent erosion, provide shade and wildlife habitat (when native species are grown), and offer many other benefits. And while protection of large, old trees is essential, planting new trees is crucial, and they too must be protected so they can grow to a ripe old age.
If you’ve planted, or are considering planting trees in an urban or suburban setting, here are a few things to be aware of that will help your trees grow strong and healthy, as well as potentially harmful things to avoid:
• The best time to plant trees (and most other plants) is autumn — as they are entering dormancy and as the rains begin. Following leaf drop, however, they are anything but dormant below ground and the Pacific Northwest’s wet, relatively mild winters give them a chance to produce fairly well-developed root systems before the aboveground demands of spring and summer are thrust upon them.
• When deciding which species to plant, choose trees that are locally native to provide the most benefit to wildlife. Also consider light, moisture and soil conditions, as well as topography (since certain species are better at controlling erosion than others). If the area is difficult to water, choose drought tolerant species. Also consider the amount of space you have: Don’t plant too close to property lines (I recommend at least 10 feet from property lines), paths and buildings, and check with utility companies if electric lines or gas or water lines are an issue.
• Before planting a sapling, remove any lawn or other plants (especially invasive species) in a circular area, 4 to 8 feet in diameter or out to the drip line (the circular area directly under the outer edges of the tree’s branches), whichever is larger. Dig a hole twice as wide and slightly deeper than the root system; the roots should fit into the hole without being cramped. Rough up the sides and bottom of the hole with a spade or similar tool. Trim off any dead or damaged roots and branches with clean pruning shears. For bare-rooted trees, mound a cone of soil at the base of the hole and drape the roots over it, gently untangling roots if necessary. For potted trees, massage the root ball to loosen and unfurl roots that are tightly wound; otherwise they may be difficult to establish. Note: when transporting non-bare-root trees, always support the heavy root mass from below; never lift or carry them by their stems.
• Place a straight stick across the top of the hole to help judge the depth at which to plant. Since the number a major cause of tree mortality is planting too deep, be sure to place it slightly above the level grown at the nursery. Straighten the tree, judging its posture from several angles. Replace the original, native soil around the roots until the hole is filled halfway, lightly firming to avoid large air pockets, then water. Once it’s drained, adjust the depth of the tree if necessary, and backfill with more soil, firmly tamping it down to prevent air pockets. Water again thoroughly. Apply about 3 inches of organic mulch to the area, keeping it at least 6 inches away from the trunk, but slightly thicker on the outer edge to prevent erosion. Don’t use fine bark mulch or gravel or rocks.
• When saplings are planted, they’re often staked, regardless of whether or not they need it. Staking is actually only helpful if they are planted in very windy areas, if they are bare-rooted, or if they have little root mass. Plants need to experience movement — just as we do — to become strong and healthy, and improper staking can cause irreversible damage. Staked trees often have weaker trunks and less developed root systems than trees that are not staked. To test whether or not a newly planted tree needs staking, grab its trunk and move it back and forth after planting; if movement causes shifting soil, stakes will stabilize it. If necessary, small trees can be supported with two 5- to 6-foot-long stakes (on either side) driven 1 to 2 feet deep (depending on soil conditions) outside the root zone. To stake a very large tree, space two to four stakes equally around the hole, placed several inches away from the root ball of a containerized plant and 2-3 feet from the trunk of bare-root trees, preferably before planting—if afterwards, stakes should be placed just outside the planting hole to prevent damage to roots. The stakes and ties should be situated perpendicular to the prevailing wind when space allows. After planting, tie the trunk loosely to the stakes, about 3 feet from the ground, with a soft tie such as twine (never use wire) in a figure-eight loop, so that the tree is not completely immobilized and can move a bit with the wind. Very small trees can be loosely tied to a single stake. Check ties periodically to be sure they’re not too tight or causing abrasion. Remove ties as soon as the tree is stable in the ground, usually within about one year.

• Immediately after planting a tree, always remove any sticks or rods that are taped to the trunk, since failing to remove them can lead to girdling, as shown in this photo. They are only meant to prevent damage to the trunk during transport; they are not meant to be taped on indefinitely.
Tree irrigation (“gator”) bags have limited benefit and often cause more problems than they’re worth! On my winter walks I often see young trees with their lower trunks covered in such plastic, and I unzip them whenever possible to allow air to reach the damp bark.

The problem is this: Eventually, the plastic (or almost anything that covers a tree trunk) will lead to a moist, dark, low oxygen environment that damages the bark and allows pathogens to invade. These bags are not meant to be left on year round, especially during the rainy season, so please remove any that you have, inform neighbors, or unzip those that you see (guerrilla unzipping, anyone?) In addition, these bags are only meant to be used for about one year, since following that period a tree’s root spread will generally be directly below the drip line (the circular area located directly under the outer circumference of a tree’s branches). Most water absorption occurs by feeder roots at the drip line (or in some species, such as oaks, quite far beyond it), so watering close to the trunk does no good (the vast majority of trees do not have tap roots) and can even cause roots to grow in a circular or spiral pattern around the trunk at or beneath the soil line, which can lead to a gradual girdling or strangling the trunk. What’s the alternative? Old-fashioned watering with a hose or watering can. Researchers who looked into artificial watering devices found no evidence that watering devices benefit tree growth and health, compared to direct watering. One possible advantage of using watering devices is less surface runoff due to their slow release, but the hazards of using bags more than a year or two (at most) is not worth the risks. Bags have to be filled with a hose or watering can, so why not just use those? Doughnut-shaped devices (or “ring bags”) don’t keep bark as moist (although they can keep the base of the trunk wet), but like gator bags, they also only apply water at the base of a tree’s trunk, so should definitely not be used for more than a year or so. Here are some good tips on watering trees from OSU.



















































shrub or multi-stemmed small tree produces fragrant, five-petaled white flowers in early to late spring that supply food for native bees, hummingbirds and butterflies. Beautiful bluish-green leaves—that provide food for many types of butterfly larvae—turn gold to reddish-brown in autumn. Delicious “berries” (botanically speaking, a
Mid to late spring flower clusters offer nectar and pollen for native bees; the soft fruits ripen in summer when they reach a deep purple (mid-June into July in my low elevation yard). Like all wild fruits, they are very
that comes without prickles. Its large, deciduous, soft and velvety leaves may be used by leafcutter bees for nest building.




may lead to starvation and possibly local extinction. Sadly, that is the case with most yards. If we really want to help birds, we need to realize that their lives are in our hands. Small changes for us will be colossal for them.





In fact, studies 




days, give it a good scrubbing every week or two, and keep it out of reach of marauding cats and dogs. Plates or shallow bowls filled with clean pebbles or gravel and water will provide for insects; butterflies will also appreciate mud puddles which they use to obtain moisture and nutrients essential for breeding. Artificial ponds should be shallow on one side and have gradually sloping sides so tiny animals can get out easily. More tips
and other small creatures. Leave seed heads and flower stalks on perennials until spring is well under way to
windy day. Dampen it, poke a some small holes, then top it with 4 or 5 inches of weed-free compost (leaf compost is good) and fallen leaves over that. Leave it to decompose for at least several months (until grass roots have died) before planting. Removing lawn via a sod cutter or spade can damage tree/shrub roots.
kitchen garden to warrant a control, consider hand removal, barriers and screens, companion plants, or simply sprays of water from the hose. Allow a natural balance by welcoming natural pest control such as 











as an elm. Sharp cuts that don’t leave stubs (partially amputated branches not cut back to the branch collar that look like you could hang a hat on it) will allow for faster healing and may prolong the life of the tree. But if safety is not an issue, consider that natural, important habitat is created when damaged limbs are simply left on the tree. As I wrote in my book, “interactions between wildlife and decaying wood are fundamental to ecosystem functions and processes in forests, aquatic habitats,” 

roughly 15 feet tall and cut back branches. If that’s not possible and you must cut it down, leave the trunk on the ground where it won’t get in your way and leave the stump. If you already have a snag, retain or add native shrubs near its base. They will help keep it protected from weather extremes and provide connectivity, leafy cover, and additional forage for wildlife.
them into your landscape, and the wild ones will thank you.
the quiet beauty that unfolds during all stages of natural decomposition and regeneration. Imagine a “nurse log” in your own yard that will increase biodiversity by providing decades of nutrients and moisture to other plants and soil organisms. While natural, moss-furred nurse logs (fallen forest trunks and limbs) provide complex substrates for regeneration of trees in intact forests, there’s no reason you can’t foster similar function in your yard (but never remove nurse logs from a forest!). Surround a fallen giant with local native ferns and other shade lovers to blend and complement, and the mystery and magic begins. It rots slowly at first, then begins to crumble away, providing more sustenance for other species. After a few decades (or a great deal longer, depending on the species), the log will be reduced to nothing but fragments, but the soil—nurtured, enriched, and full of life—will pass on its riches. Fallen logs hold large amounts of water and nutrients like nitrogen and phosphorus and, with time, concentrate those nutrients to provide even more. And new lifeforms such as bacteria, fungi, protozoa lead to salamanders, beetles and millipedes.
nuthatches, woodpeckers, swallows, or owls that is sited correctly and is accessible for annual cleaning. Though not as good as natural nest sites due to their inability to insulate as real tree cavities do, boxes are better than nothing.
gardens, complete with native plantings and other elements that support entire life cycles of local biodiversity, ought to be paramount. Priceless benefits to us (crop pollination and a chance to admire nature’s beauty), to countless other species that rely on plants or insects for food, and to plants (pollination), come with the package.


area) attract and support a diversity of native insects and other creatures; recognize the 












flower’s anthers, thousands of male pollen particles are released, pollinating its flowers. Other pollinators attracted to scent include bees, but also 

caterpillars and other insect life than any other genus in the northern hemisphere. This proficiency is especially important during breeding season, when the vast majority of landbirds consume and feed their young highly nutritious insects or their larvae, and other arthropods such as spiders—not seeds or fruit. Other studies show a higher diversity of bird species in oak forests than in nearby conifer forests (although 


cerasiformis), serviceberry (Amelanchier alnifolia), snowberry (Symphoricarpos albus), oceanspray (Holodiscus discolor), 

Moreover, some fruit-eating species may get intoxicated by eating fermented berries and are more likely to hit windows while flying “drunk.”

year, quite a bit more than deciduous trees. They also provide habitat, beauty, shade and cooling and help stabilize soil. Don’t prune out lower limbs unless it’s absolutely necessary.
◊ Use only organic fertilizers when necessary (excess can be washed into waterways), and don’t use pesticides.
As fall moves forward, the cells in the abscission layer become drier and weaker and leaves eventually part company with the plant. Many trees and shrubs lose their leaves when they are still colorful (making for some gorgeous mulch!), while some retain the majority of their foliage through much of winter, though their leaves lose color fairly quickly. Like chlorophyll, the other pigments eventually break down in light or when frozen. The final pigments are tannins, which look brown. An example is the 
Scouler’s willow (Salix scouleriana): A fast-growing deciduous shrub or small tree. Flowers are soft catkins, larger than horticultural “pussy willows,” and appear in early to mid-spring. Male and female flowers are on different plants, so grow both for seeds. Scouler willow is a larval host plant for several butterfly species. Does not tolerate full shade. Prefers moist soil. 20-30 feet tall by 10-15 feet wide at maturity. 

Tall Oregon grape (Mahonia aquifolium): A handsome, multitalented evergreen shrub with an upright growth habit. Bursts into flower brilliantly in early to mid-spring, for a long period. Tolerates acidic soils. Has somewhat prickly evergreen leaves, so site it where it won’t be brushed against frequently. 5-9 feet tall by 3-6 feet wide. Will spread slowly. More info in 
hide, and myriad other ingenious things. Leaf litter breaks down with the help of mycorrhizal fungi that move carbon into soil, extract nutrients for plants and protect them from disease, lessen soil erosion, and play a very important role in
leaves. Keep piles moist (but not completely saturated). During excessively rainy periods, consider covering the pile if possible. In a year or more (depending on the type of leaves used), after the leaves have broken down, you will have some very dark, crumbly humus to add to your veggie beds and other places that need high quality soil (but as mentioned below, remember that covering bare soil with any mulch can kill ground-nesting bees, so be sure to check the soil before applying).



◊ Campanula rotundifolia (common harebell): Perennial. 1-2 feet tall x 1-2 feet wide. Sun to part shade. Moist to dry, well-drained soil, preferably with a good amount of organic matter. Spreads slowly by rhizomes or seed. Bell-shaped, bluish violet flowers typically bloom through late summer. (pictured left)
Tolerates wide range of soils; prefers moisture but tolerates drought when established. Spreads by rhizomes or seed. Bright gold, fragrant inflorescences typically bloom well into fall. (pictured right)




Birdbaths: Birdbaths that slope gradually are best because all sizes of visitors can wade in to a safe and comfortable depth. If you already have one that has steep sides, place some flat rocks on one side to create a shallow area. Site birdbaths in open areas, at least 10 feet from any hiding places were domesticated predators could lurk. Use hanging birdbaths whenever possible if predation is a problem in your yard. And keep them as clean as possible: Replace the water every day or two (this will also keep mosquitoes from breeding) and give them a good scrubbing every few weeks, but don’t use bleach.
Plates of moist gravel: Beneficial insects and other small arthropods will sometimes come to shallow birdbaths, but ground dwellers—like beetles—will appreciate a plate or pie pan filled with clean pebbles or gravel and water, and placed on the ground out of hot sunlight. Just be sure the water doesn’t rise above the gravel so that no one drowns.





















occasionally watched as she molded the nest by pinching materials — plant fibers like moss, bark, bits of leaves bud scales, and lichen, as well as feathers or fur, all held together by spider (or caterpillar) silk — between her bill, chin region, and chest while rotating her body. The interior was stomped on by her impossibly tiny feet. Nature’s silk is strong, sticky and stretchy (able to stretch up to 40 percent of its length without breaking), and helps make a nest that is flexible, expandable, and able to accommodate rapidly growing babies. The latest photos show that extra lichens were added as a finishing touch for camouflage (although I like to think that she added them as a charming decoration as well!).
She chose to place her nest within 20 feet of two native red-flowering currant shrubs that had just begun to bloom. Besides currants, other native early bloomers important to these solitary birds include osoberry and Oregon grape. Later on they’ll be attracted to the flowers of native huckleberries, ceanothus, twinberry, serviceberry, 

the next phase of their relationship—the egg-laying period—when she will need him the most. Egg laying is immensely draining on a female’s energy reserves and her partner’s support is essential for her health, as well as that of their young. She needs to eat frequently, and during this time I sometimes see the male come near the nest and perch, singing a soft fee-bee song. She then flies to him, utters a tiny, high-pitched begging call and does a little wing-quiver. Dad then feeds her and she returns to her incubation duties in the nest. Sometimes he simply feeds her at the nest box’s entrance. If he’s not around, she may take matters into her own wings and forage briefly for herself. 

how our eyes travel through a space, for providing unity, balance, and crucial wildlife habitat. And structure can rev up “curb appeal”: A house looks best when it softly blends into a landscape and one way to do that is by nestling it within or framing it with medium to large trees (size being dependent on the dimension of your house and yard), but not completely hiding it. Trees should be planted a minimum of ten feet from buildings, preferably more. They offer myriad other benefits, like shade on sultry summer days (particularly when placed to the southwest of a house),
the bees and hummingbirds will be very pleased with their flowers. Keep manmade elements to a minimum and keep them simple to achieve a sense of flow and to complement—not overpower—the plants.
evergreen huckleberry (Vaccinium ovatum), Oregon grape (
Intricately divided fronds of the lovely 
Whoever said that winter landscapes are drab and lifeless didn’t consider the possibilities. With a little ingenuity and planning, your garden can be a winter wonderland—in spite of short days.





s and often have precise dietary needs. When environmental conditions change, generalists like us are usually able to adapt (at least so far), but specialists often become victims who silently go extinct: They can’t simply move on, quickly change their diet, or “reinvent” themselves.