Tag Archives: trees

Trees of Stanford University

Flame_treeThe other day I visited the campus of Stanford University to view something from their archives. The campus is beautiful. Flowering trees in bloom every where you look. I was told by a colleague that Stanford has a huge collection of trees some planted back in the late 1880’s when the university was first built and the landscaping installed. The designer, Frederick Law Olmsted, the famed landscape architect also created New York’s Central Park. I wanted to find a mature specimen of a California native, the Catalina Ironwood, which is listed in their Encyclopedia of Stanford Trees, Shrubs and Vines.

The campus is huge and with so many areas to explore I missed the grove of Ironwood. There are over 400 species, 150 genera and 60 families which total 27,000+ individual trees growing on the central campus. Senator Leland Stanford vowed that no healthy oak be cut down and even today the dominant tree on campus is the coast live oak. There has been a loss of diversity from the original tree and shrub plantings of the 1880’s and 1890’s, which is well documented for conifers. Still the sheer number and variety of trees is impressive.

In the main quad by the Memorial Church and the grounds surrounding the Music library and the Green library I found dozens of trees which were all surveyed and named on a map I found online. It was fun to locate each tree.

I’m always on the lookout for mature tree specimens to photograph. When I recommend a tree to be included in a design I like to be able to share the image of what the tree will look like in the future. Trees anchor your house to the land. They are more than just a pretty face to look at from the kitchen window. They provide habitat, food and shelter to birds as well as giving shade in the summer. Some of the trees I saw on the Stanford campus may not be suitable for all gardens but they are interesting to learn about. Here are a few of the highlights of my campus botanical adventure.

In the main quad there are 8 circular planting beds containing over 80 individual trees. One that I was attracted to because of its unusual trunk and branching structure was the Flame tree or brachychiton acerifolius. Although not yet in bloom it will soon be covered with scarlet bells. I learned from the campus encyclopedia that this tree was planted in 1998 after the original specimen died. That flame tree, planted in 1891, was famous for the brilliant display it put on in May and June, covering the ground with a mantle of red bells. The pod-like fruits contain masses of irritating bristles but also nutritious yellow seeds that were eaten by the Aborigines after toasting.

The next tree that caught my eye had such formidable thorns that I wondered where it grew naturally. Floss-Silk_treeHow could it come by the pretty name, Floss Silk tree, with those deadly spines? I learned in September this tree redeems itself with masses of showy pinkish-white flowers so numerous they hide the foliage. Hummingbirds enjoy the nectar of the flowers which are used in Brazil as threads in upholstery. But the most distinctive feature of the tree is the wicked looking array of stout spines that crowd the trunk and protrude by an inch or more. Who knows why they evolved this way? The fruit of the Floss Silk tree is very large and on ripening the pods open to expose masses of white cottony kapok-like material that perhaps acts as a barrier to rats seeking the tiny seeds. Is it rats that the trees are hoping to deter by growing the huge spines?

Red_mulberryRedwoods, giant sequoia and Bristlecone pine live a long time but there’s something impressive about an ornamental tree that is over 100 years old. Planted in 1889, the trunk of the Red Mulberry tree growing in the quad has attained great character and girth. Mulberry leaves are the food of the silkworm and if you grow your own silkworms you can make silk. One silkworm produces about half a mile of incredibly strong monofilament to make its cocoon. The pale berries of the red mulberry are not as good to eat as the black mulberry but both grow quickly to provide shade for your home or patio.

A tree planted for beauty shade, habitat and posterity is a gift to all.

Tree Pruning Tips

limbed redwoods.1600The big wind we experienced not long ago was just the beginning of the wild weather that is coming our way. Looking up at the trees violently swaying from one side to the other I wondered how they could survive such strong wind gusts. Not all of them do survive coming down and blocking driveways, roads and sometimes landing on a house or a car. There are ways of trimming, pruning and managing trees that can help them stay upright in a strong wind. Don’t endanger yourself, your family, your property or your valuable trees by mismanaging this valuable resource.

You’ve seen it. A homeowner wants more sun and has their redwoods limbed way up so there is just a a tuft of branches and foliage at the top. Living in the forest myself I can understand the desire for more sun. Why is this bad for your trees? What is a better way to ensure the health of the tree and still have space to walk or park under them or open up a view?

Raising the height of the lowest branches or limbing up is often done to create clearance in an area where people will walk or park. Seven feet is your target height . Over pruning removes many of the energy producing needles and leaves taking away most of the trees ability to photosynthesize. Evergreens don’t have food reserves like deciduous trees. They may even die completely in 8-10 years or topple in a heavy wind because they have become so top heavy and have lost their windbreak effectiveness.

Removing the lower limbs of redwood, cedar, pine or other conifer is needed to remove dead and dying branches which improves circulation and makes them more fire resistant. It’s done naturally in the woods when limbs die and fall off. If you must remove live lower branches do it over a longer period of time to reduce stress on the tree. The amount trimmed off should not exceed 25% of the total foliage. 10-15% is better but not always attainable.

Windowing of a tree should follow the same guidelines. To open up a view and preserve the health and beauty of your trees, here are some ways to make views and trees work together. According to Plant Amnesty, windowing or cutting selected branches, works best when the subject is a large, close-in tree blocking your view. By carefully choosing what to cut you can open a window in that tree to give you a fully framed view of whatever lies beyond. Like most pruning, there’s a certain amount of art involved in this. Never top a mature tree it’s arboreal butchery.

If you’re trying to decide whether or not to limb up evergreen trees in your yard, do your homework first. Oregon State University Extension Services recommends pruning when the treclear cut hillside.1600e is not actively growing. This is late winter to very early spring, well before any new growth will take off in the new season. For our area January and February is best. Redwoods go into a short period of dormancy at that time making it the best time for pruning. This gives them a chance to heal the cuts you make with their first burst of new growth in the spring.

Another scenario that wreaks havoc with the land is to clear cut large sections of forest. When you do this the trees left behind on the fringes are not prepared to deal with high winds. They grew up being protected by the trees around them and their trunks are not as strong. Trees channel the wind over the top and buffer it before it hits the ground. By clearing the land completely the wind barrels through the open area and hits the next thing in its way which may be your house or deck or landscaping. It’s better to remove selected trees completely.

Put away the saw and enjoy the beauty of your mature evergreens. Prune lightly. Preserve your trees natural shape. A properly pruned tree will look as natural as possible.

Why We Love Trees

When you look out your windows into your landscaping what catches your eye first? Maybe the hydrangeas are looking beautiful about now covered with giant flowers in sky blue, dark pink or white. Maybe it's the purple and red spikes of your salvias that both you and the hummingbirds enjoy. But I'll bet the most majestic and inspiring sight in your garden are the trees that frame your house giving it a sense of permanence, welcoming you home and providing a haven for songbirds that serenade you on a spring day.

cornus_capitata_closeupLarge or small trees make the world go round. They produce oxygen and act as a giant filter that cleans the air we breathe. A mature leafy tree produces as much oxygen in a season as 10 people inhale in a year.

Trees clean the soil by absorbing dangerous chemicals and other pollutants that have entered the soil. They can either store harmful pollutants or actually change the pollutant into a less harmful form. Trees can filter sewage and clean water that runs off into our streams. They can absorb and lock away carbon dioxide as wood so it is not available as greenhouse gasses.

If you live near a busy street trees can muffle the noise almost as effectively as a stone wall. They also act as a windbreak during windy and cold seasons reducing the drying effect of the wind and keeping it from blowing  precious topsoil away.

Trees slow storm water runoff helping to recharge our Santa Margarita and Lompico aquifers. On top of all the cool things trees do for us they provide shade and cool us in the summer. In the winter they break up the wind reducing heating costs. Trees increase property values.

If you've been thinking about adding a few trees to your own property here are some of my favorites. Some don't get enough recognition and some are classics. All make great additions to the garden.

Early in spring the flowering plums and cherries let us know that winter is over and a new season has begun. Then the dogwoods start to bloom and we're awestruck. Maybe you know of an especially beautiful specimen that gets your attention each year when it blooms. There are a couple varieties that I like to include in designs that are easy to grow and live for many decades.

Introduced to me by Barrie Coate, the renowned arborist and horticultural consultant, the Evergreen cornus_capitataDogwood, Cornus capitata, is also known as Himalayan flowering dogwood and lives up to its name in every respect. This under used tree is breathtaking in late spring and early summer with large flower bracts over 3" across.  A friend has one in her garden and it is the showiest tree on her property for several months. This variety is slow growing reaching 20 ft tall in sun or partial shade after about 25 years. After flowering, red fruit provides a treat for the birds.

Another dogwood variety that makes a wonderful addition to the garden is the Venus dogwood. I've heard it said that some consider it even showier than the Evergreen dogwood but I like them all. It's a fast growing deciduous hybrid with white flowers as large as your hand. Summer flowers give way to strawberry-like fall fruit as the leaves turn color. It's highly resistant to disease and drought conditions.  What's not to love? I also recommend Cornus Eddie's White Wonder for it's beauty and disease resistance.
Cercis_Forest_Pansy
If you would like a tree in a certain spot but don't have lots of room, consider  a Drimys winteri, commonly known as Winter's Bark. This evergreen, slender tree from Chile has aromatic mahogany-red bark which cured sailors in past centuries from scurvy and leathery fragrant leaves. Small clusters of jasmine-scented, creamy white flower appear in winter and spring. It grows to only 20 feet tall.

Other trees that are favorites of mine include Forest Pansy redbud for its stunning red foliage and Sango Kaku Japanese maple for its year round interest. Arbutus Marina, Oklahoma Texas redbud and Tristania laurina Elegant are also wonderful trees for the landscape.

Plant a tree for yourself and future generations.
 

Saving Trees by Removing Ivy & other tips

Well, it’s that time of year again when all things seem possible. Hope springs eternal –  the spring will be warm and the veggies will get off to a good start this year. That torrential rains won’t knock off the fruit blossoms and that all will be right with creatures big and small.  The narcissus are blooming already signaling the start of the new season.

An important thing to remember is that garden is a verb as well as a noun. It’s the act of gardening that’s important not so much what your garden looks like. So relax a little and enjoy it. With that in mind here are some tips to improve the health of your garden.

I received an email from a reader asking that I please advise people to save the life of their trees, including redwoods and oaks, by removing the ivy that grows up the trunk. Ivy can kill trees by tightening its hold on the trunk while both of them grow and can eventually stop the supply of nutrients and water from the roots to the branches. Trees supporting heavy ivy growth can be uprooted or broken by wind. The environment ivy creates is also harmful to trees. It keeps moisture against the bark of the trunk, creating a state of constant wetness which attracts insects. It covers up any developing problems with the tree. Many tree diseases and decay became major problems because they were hidden by ivy growth.

If you have a tree with a lot of ivy coverage, there are a few simple steps you can take to remove the ivy. Go around the tree and cut out a vertical section of ivy about 1-2 feet wide around the entire tree. A large screwdriver or forked garden tool can be used to pry and snap the cut section away from the trunk. The lower portion of ivy will need to be pulled and cut off periodically to prevent further growth from the base. The upper ivy will die on its own and can be removed much later when it’s easier to pull.

What else should we be doing to enjoy our gardens more?
    Use plants that bloom over a long season, have colorful leaves and attractive bark and berries.

    Garden on a small scale using containers and small, easy to manage plots for organic vegetables, flowers     and herbs.

    Add low voltage, LED or solar lighting so you can use the garden after dark.

    Furnish your patio during the warm season with pots, furniture,a fire pit and a patio heater.

    Add water to your garden with a small recirculating fountain or pondless waterfall.
gold, chartreuse, variegated or burgundy colored foliage in the     garden. Abelia Kaleidescope paired with Purple Smoke tree is one of my favorite combinations.  A combo     to try for the shadier parts of the garden is Black mondo grass with white variegated Jack Frost brunnera.     Look at your garden as a series of small vignettes and pair new plants together you haven’t tried before.
    Go through one of your seed catalogs and see what’s being offered in these tones.

Remember that garden is a verb as well as a noun. It’s the act of gardening that’s important not so much what your garden looks like so don’t sweat the small stuff.    
   
 

National Arbor Day 2010

National Arbor Day was founded by J. Sterling Morton in 1872 and is celebrated on the last Friday in April. This year it falls  on April 30th.  The simple goal of this day is to inspire people to plant, nurture and celebrate trees.  So whether you’ve been thinking about planting a fruit tree to feed the family, a shade tree to save on summer cooling, a flowering tree to attract pollinators, or some trees to hang the hammock on this is a good time to plant as well as nurture and celebrate all trees.

Trees are remarkable in how they grow and adapt to their environment.  Some trees, like crape myrtle, sycamore, madrone and cherry have especially beautiful bark. This is the tree’s protection from the outside world. Continually renewed from within, it helps keep out moisture in rain and prevents the tree from losing moisture when the air is dry. It insulates against cold and heat and wards off insect enemies.

The inner bark, or phloem, is the pipeline through which food is passed to the rest of the tree, It lives for only a short time, then dies and turns to cork to become part of the protective outer bark.

The next layer in is the cambium cell layer which is the growing part of the trunk. It annually produces new bark and new wood in response to hormones that pass down through the phloem with food from the leaves.  These hormones are called auxins and stimulate growth in the cells.  They are produced by leaf buds at the ends of branches as they start growing in spring.

Inside the cambium layer is the sapwood or xylem which moves water from the roots to the leaves. Sapwood is new wood. As newer rings of sapwood are laid down, inner rings lose their vitality and turn to heartwood.

Finally, the central supporting pillar of the tree is called heartwood. Although dead, it will not decay or lose strength while the outer layers are intact. A composite of hollow, needlelike cellulose fibers bound together by a chemical glue called lignin, it is in many ways as strong as steel.

Leaves make food for the tree. Their shapes help them reduce wind resistance, shed rain that could decay the leaf if left standing and produce chlorophyll. The narrow needles of a Douglas fir, for instance, exposes as much as three acres of surface to the sun.

There is a tree to please everyone. Don’t have much space for a fruit tree? Consider a Garden Annie dwarf apricot, a dwarf Garden Prince almond, Compact Stella cherry, dwarf Red Sunset nectarine or a Garden Delicious apple.

Rather not have fruit to contend with? How about a flowering crabapple, cherry or plum? Want a deciduous shade tree that grows fast? Red maples with blazing fall color fit the bill.

Need to screen a neighbor quickly? Then plant a honey locust or catalpa. Another fast growing,deer resistant tree is the silk tree.   It’s flat topped, spreading canopy make this a good patio tree and is especially beautiful when viewed from above, as from a deck or hilltop.  If left unpruned it will become a multi-stemmed tree but with training can be grown as a single trunk 10-20 foot umbrella.   Fluffy pink flowers like pincushions bloom in summer.  Grow it in full sun to partial shade.  With regular water it grows fast.  They are attractive to birds, too. 

Be kind to your trees. They are a valuable asset to your home and our environment.

Planning this Summer’s ‘Staycation’

Picture yourself this summer with your family outdoors  during your  "staycation" – relaxing, cooking on the barbie, entertaining, playing with the kids or maybe just reading in the shade. Maybe you need to make some changes to truly have a relaxing backyard.  Now is the perfect time to plan while the yard is still a bit bare and you can see the space for what it really is.  Here are some ideas to get you started on your backyard makeover.

Make sure you have enough shade in your garden to keep everyone comfortable in the hot summer. We usually get a heat wave in May so be prepared early.  National Arbor Day in the last week of April but each state sets its own day of celebration. California celebrates this week, March 7-14, as the week to plant a tree.

There are so many good choices for our area.  First, determine how wide and tall you want your tree to grow. Next, know your soil and growing conditions.  Those who live in sandy areas might consider a strawberry tree, chitalpa, crape myrtle, Grecian laurel, fruitless olive, Chinese pistache, Purple Robe locust, California pepper tree or native oak.  Good choices for those who live with clay soil are arbutus ‘Marina’, western redbud, hawthorn, gingko, Norway or silver maple.  If you have quite a bit of shade but still need a bit more for the patio area, think dogwood, strawberry tree, Eastern redbud or podocarpus.

What would entice everyone out to the backyard after dark when it’s cooler? How about a simple metal fire bowl set on gravel, with brick or pavers?  If a piece of crackling firewood throws any sparks, they fall on the the gravel and expire.

How about a hidden getaway to read or just sit and relax? All you need is a quiet nook carved out of the larger garden.  Place a comfortable chair or love seat on some flagstone pavers, add a table and a dramatic container planted with flowers or colorful foliage and your retreat is complete.

After you’ve planted your tree and planned your hidden getaway take advantage of the moist soil to fertilize your garden .  Lawns and groundcovers are beginning their spring growth spurt and new leaves on trees, shrubs and perennials are starting to emerge. Spread compost, manure, or organic fertilizer to help plants get off to a strong start.  If you need to move any plants in the garden, now is a good time.  Plants are full of growth hormones and recover quickly from transplant shock. Pull weeds regularly before they set seed. They pull out easily from moist soil. Think of weeding as free gym time. The last frost of the season is approximately March 15th.  Spring is on its way.