Category Archives: trees

Tree Varieties You’ll Love

We have Joyce Kilmer to thank for her poem ‘Trees’ that starts with the famous line:
I think that I shall never see
A poem lovely as a tree.

In nature and in the garden it’s the trees that get most of the attention. Cambridge Dictionary defines the Wow Factor as a quality or feature…that makes people feel great excitement or admiration. Majestic and dramatic, no matter the size, a tree makes a garden or landscape speak that it’s here to stay.

Brahea armata – Mexican Blue Palm

Recently I had the pleasure to spend some time in a historic garden that dates back to the 1800’s. Last year this garden was featured on the Garden Conservancy Santa Cruz Open Days. The Conservancy’s mission is saving and sharing outstanding American gardens so I was thrilled to tour this garden, be introduced to several new tree varieties plus see some old favorites that might just work in your garden also.

Many of the hundreds of tall bearded iris were still blooming in the garden as well as early flowering perennials and shrubs. I didn’t see any dragonflies flitting about on this particular day but the stunning ornamental gate and mosaic created on one of the garden paths both feature dragonflies and I’m pretty sure they are regular visitors. The garden is called Odonata which is the order of carnivorous insects encompassing dragonflies and damselflies.

An unusual flowering dogwood from Mexico. Cornus florida ‘Pringle’

One of the most unusual flowering trees in Odonata was the Mexican flowering dogwood. This small ornamental tree, a cornus florida subspecies called ‘Pringle’ had the most unusual flowers. Their white bracts don’t fully open giving them a Chinese lantern look. This tree holds its foliage later than the more familiar Eastern dogwood and has reddish fall color. Glossy red fruit that forms later in the season is readily eaten by birds. This tree is showy and best used where the flowers can be appreciated.

Wedding Cake Tree or Cornus controversa ‘Variegata’

Another dogwood variety growing nearby was also new to me. Cornus controversa ‘Veriegata’ (Wedding Cake Tree) is graceful and spectacular with beautifully layered horizontal branches. Winner of the prestigious Award of Garden Merit by the Royal Horticultural Society the tree was covered with showy creamy white flowers in flattened clusters. Later the blossoms will give way to black berries in late summer that is, if the birds don’t get them first. Fall color is a lovely yellow color.

Golden Chain Tree aka Laburnum x watereri ‘Vossii’

Also in bloom, a laburnum x watereri ‘Vossii’ (Golden Chain Tree) looked spectacular with long, drooping clusters of lightly fragrant, bright yellow flowers. This handsome tree has a beautiful spreading canopy of bluish-green foliage and is a great choice as a single specimen or even in a group planting.

Honorable mention awards would have to be shared between the red form of Henry Lauder Walking Stick ‘Red Dragon’ and the white Flat Rock leptospermum. Well maybe the cryptomeria japonica ‘Dacrydioides’ (Whip Cord Japanese Cedar) or the pinus wallichiana “Zebrina’ (Striped Himalayan Pine) would also place.

Pittosporum ‘Silver Magic’

There were so many other note-worthy specimens in this garden. From showy shrubs like pittosporum ‘Silver Magic’ to large palm specimens such as Mexican Blue Palm and a giant bromeliad variety called a puya this garden is a landscape designer’s candy store. I even enjoyed the more common plants like lomandra ‘Platinum Beauty’, variegated fortnight lily, a huge heuchera ‘a la Rochette’ blooming alongside a brilliant blue native pentstemon as well as gold flowering Moonshine yarrow.

It was an afternoon to remember between rain storms.

Arbor Day in California

California’s Arbor Day is celebrated on March 7th, in honor of famed horticulturist Luther Burbank’s birthday. The day is celebrated on different dates around the world because one of the features of Arbor Day is the planting of trees which is best done at certain times of the year. The simple goal of this day is to inspire people to plant, nurture and celebrate trees.

Second growth redwood fairy ring.

We are fortunate to live here in the Santa Cruz mountains in a temperate rain forest with lots of trees. Our redwoods are especially important in our biodiverse watershed as is all flora and fauna in the forest. Redwoods and many native trees keep our environment moist. Let’s make it a priority to protect them and pass the baton of stewardship to our children who will inherit this place.

So whether you’ve been thinking about planting a redwood, heritage oak or other native tree, a fruit tree to feed the family, a shade tree to save on summer cooling, a flowering tree to attract pollinators, or a tree 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 redwood, ponderosa pine, sycamore and madrone 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. Bark 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, needle-like cellulose fibers bound together by a chemical glue called lignin, it is in many ways as strong as steel.

fog filtering through the redwood trees.

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.

Be kind to all trees. They are a valuable asset to your home and our environment. Earth Day is next month on April 22nd. Let’s continue to celebrate the natural beauty of our planet and learn what we can do to keep it healthy.

Trees for Shade, Wildlife and the Future

We don’t plant enough trees. Everyone wants an instant garden but nature doesn’t work that way. When you look out from your windows into your landscaping what catches your eye first? I’ll bet the most majestic and inspiring sight in your garden is probably a tree that frames your house giving it a sense of permanence, welcoming you home and providing a haven for songbirds that serenade you on a summer day.

Japanese maple- Stanford campus

Large 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 the harmful pollutants or actually change the them into a less harmful form. Trees can filter sewage and clean the 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.

Gingko biloba

Trees slow storm water runoff which helps recharge our aquifers. On top of all the beneficial things trees do for us they provide shade and keep us cool 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 others are classics. All make great additions to the garden.

I like Forest Pansy redbud for its stunning red foliage, Sango Kaku Japanese maple for its year round interest, Strawberry tree, and Tristania laurina Elegant. Evergreen Dogwood, Cornus capitata, is also known as Himalayan flowering dogwood lives up to its name in every respect. 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.

To make your garden more compelling also consider planting a Ginkgo biloba ‘Autumn gold’ or Amelanchier ‘Autumn Brilliance’. Also called Apple Serviceberry it has edible small fruits you can use in jam and grows fast. Chinese Fringe Tree has magnificent clusters of fragrant, fringe-like blooms and is a terrific accent for small yards.

Swan Hill olive

We are all familiar with the huge flowers in late winter of the Saucer magnolia. This beautiful tree also makes a good lawn tree. Oklahoma redbud takes heat and drought but can also tolerate regular garden watering. Chitalalpa ‘Pink Dawn’ grows 12 feet in three years then grows more slowly to 25 feet with a 25 foot spread. It’s pink trumpet shaped flowers are a welcome sight during the summer. Crape myrtle also blooms at the same time providing your garden with color when you’re outdoors the most.

‘Swan Hill’ olive produces no pollen or fruit, takes drought conditions and casts light shade. Chinese pistache provides brilliant fall color growing to 35 feet by 30 feet wide.

Plant a tree for yourself and for future generations.

 

Flowering Trees & Shrubs of Early Spring

Outside my window the Blireiana flowering plum is covered with dark pink, double blossoms. It’s one of my favorite early spring blooming trees with a sweet fragrance strong enough to scent the garden. We look forward to the earliest flowers of the new season knowing that winter will soon be over. Spring officially begins on March 20th.

Old fashioned shrubs like flowering quince and forsythia figure prominently in many old gardens because they are tough plants able to survive neglect and still look beautiful.

Forsythia ‘Kolgold’

The bare stems of forsythia are completely covered with deep golden-yellow flowers in late winter and early spring and become the focal point of the landscape when in full bloom. The showy stems of this easy care shrub are great for cutting. Forsythias are native to eastern Asia but a chance discovery in Germany by a grower who specialized in breeding for the cut flower industry led to the especially vivid variety ‘Kolgold’ in the 1800’s. Forsythia has long been used in Chinese medicine. The flower petals contain powerful bacteria-fighting properties which make it an important dressing.

Flowering quince

Flowering quince is another old garden staple providing early color. They are easy to care for and nearly indestructible in almost any soil that is well drained and not overly fertile. Once established quince is a very drought tolerant plant and their spiny branches make them an excellent choice for hedges, screening or as a security barrier. There are red, pink, orange and white flowering varieties. The Toyo Nishiki cultivar even has pink, white and solid red flowers all on the same branch.

Clivia miniata

What would a shade garden be without a bright orange clivia? Every year I look forward to their huge flower clusters that emerge from between dark green, strappy leaves. Even in dark shade they will bloom and brighten the winter garden although they would do fine in morning sun. If you have a north facing window you can grow them as houseplants. Clivia are hardy to several degrees below freezing but mine, under an overhang, have survived temps of 23 degrees without damage. Clivia breeders have produced gold and peach colored flowers also but I still like the standard orange ones.

A beautiful vine that blooms in winter is hardenbergia ‘Happy

Hardenbergia ‘Happy Wanderer’

Wanderer’. In the pea family, this evergreen vine looks like a small wisteria when in bloom. Pinkish-purple flowers cascade in clusters on twining stems that reach 12-16 feet long. It requires little water once established and is hardy to about 23 degrees. If you have an older, tangled plant you can rejuvenate it with hard pruning in early spring after flowering. Never prune in late summer or fall because you will cut off the wood that is going to bloom the following winter.

The last plant I couldn’t live without is Fragrant Sarcococca. The tiny white flowers of this plant are easily overlooked but you can’t miss their scent. I have one near the front door that greets me with that vanilla fragrance every time I walk in or out. The flowers are followed by a bright red fruit. Sweet Box forms a natural espalier against a wall and if you have a problem spot in deep dry shade where other plants won’t grow give this plant a try. They are easy to grow, deer resistant and trouble free.

Save Water – Save Trees

I had to do it. I couldn’t resist. Even though I’d vowed not to get any new plants until fall planting season when I saw the one gallon Pride of Madeira just begging for a new home I succumbed to my impulse. I rationalized this plant was on my wish list and will be drought tolerant so I wasn’t being totally irresponsible.

I’ve always wanted an echium fastuosum on my hillside. I admire those huge spires of purple-blue flowers whenever I see them in other gardens. These are tough plants getting by with no summer water once established and the flower spikes are bee magnets. I covered it with a layer of shade cloth for a few days because it was so hot when I planted it. This will help it establish more quickly while the roots take hold in the soil.

Flame_tree
Flame tree on Stanford campus

In your own garden it’s wise to establish a drought to-do list. I’m talking about what plants get your precious water and what to let go.

As we enter another dry year many of our ornamental and fruit trees are dying. Many were watered along with the lawn you have now let go brown. Others might have been surviving on natural rainfall. Whatever the case in your garden don’t let your trees die.

Nature has already killed an estimated 12 million trees in Calif. forests since the drought began four years ago. Most of these have fallen victim to bark beetles that attack trees weakened by drought.

In our own neighborhoods, trees are a long-lived asset. A tree is not something that can be easily replaced. It’s OK to appropriately water trees. Dying trees can be a safety hazard and removing a dead tree is expensive.

It takes years to grow a tree to mature size. Save and use shower and cooking water to help them out. Maybe it’s time to install an simple laundry-to-landscape system to water your landscape trees. Or set up a separate drip or soaker hose for your trees and give them a good deep drink at least once or twice a month. And remember that the tree’s feeder roots are not at the base of the trunk but out at the drip line and a little beyond.

laurel tree.1600
Laurel tree on Stanford campus

A rule of thumb for determining when to irrigate is when 50% of the water has been depleted from the soil in the plants’ root zone. This allows a buffer of water in the soil in case the weather suddenly turns hot and windy and applies to trees, shrubs and perennials.

Sandy soils hold less water than clay soils and must be irrigated more frequently. A common misconception is that it takes more water to grow plants in sandy soil than in clay soil. Actually the total amount required for the whole year is the same for both soil types. The amount of sunlight, wind, temperature and humidity control how much water a plants needs – the soil is only the reservoir.

To check the water content in the soil dig 8-16 inches down into the soil with a trowel, shovel or soil tube and feel the soil. At about 50% available water:
* Course soil appears almost dry and forms a ball that does not hold shape.
* Loamy soil forms a dark ball that is somewhat moldable and can form a weak ribbon when squeezed
between the finders.
* Clayey soil forms a good, dark ball and makes a ribbon an inch or so long and slightly sticky.

If you are planning to plant some new trees this fall, be sure they are drought tolerant natives or low water use non-natives. There are many nice specimens to choose from. And don’t skimp on the mulch.

It’s important to maintain our existing tree canopy and plant for the future. Even in times of drought, no especially in drought, planting and stewardship of trees is critical. Not just for their future but for ours as well.

The Best Dogwoods & How to Grow Them

Alluvial_Terrace_wholesale_nursery
Alluvial Terrace Nursery

There’s nothing like learning about trees from someone who has discovered for themselves what makes a winner and how to grow it. Recently I had the opportunity to tour a small wholesale nursery near Corralitos. Jon Craig has evolved from Silicon engineer to a propagator of plants and trees and he’s all the happier for it. He laughs when he says he has loved plants for a very long time starting with his first job mowing lawns. As a former engineer it’s all about the research and the plants he grows showcase his success.

His very favorite tree is the dogwood. Not just any dogwood but the ones that bloom with the largest flowers for the longest time. There are four main species of dogwood trees. From the Himalayas in China comes cornus capitata, Korea is home to cornus kousa. Cornus florida grows on the east coast and the west coast is home to cornus nuttallii or Western dogwood.

Jon_Craig_with_Mountain_Moon.1600
Jon Craig with cornus capitata ‘Mountain Moon’

We are all familiar with the Eastern dogwood that blooms early in the spring. It’s beautiful but rain and wind can cut short the flowering season many a year and the root system is prone to disease. Our Western dogwood is prone to leaf spot fungal diseases. The Kousa dogwood is a more drought tolerant, disease resistant and a tougher plant all around. Large, showy flowers open after the tree has leafed out and remain for a long time. This makes it good for hybridizing with other varieties.

The Stella series is a mix of a florida on kousa dogwood roots. Vesuvius series is a cross of our native nuttallii with a florida as is Eddie’s White Wonder. There is also a nuttullii-kousa cross called Venus that displays huge flowers and gets its disease resistance from the kousa roots. All these cultivars strive to produce a tree with superior disease resistance and huge, long lasting blooms.

cornus_capitata_Mountain_Moon_closeup
Mountain Moon

Deciduous dogwoods don’t like wet feet especially in the winter. That’s how they develop fungal disease. But there’s an evergreen dogwood that can handle moisture all year round. That tree is Jon Craig’s very favorite. With a name like Mountain Moon you can just picture it blooming high in the Himalayas. Huge flowers up to 6” wide can last from late spring into early summer. After flowering, the fruits begin to form and grow into red balls about the size of large strawberries. This is the reason is it also known as the Himalayan Strawberry Tree. They are edible but bland and tasteless to us. The birds love then though and they remain on the tree while woodpeckers and robins have a feast.

Cornus capitata ‘Mountain Moon’ is a tough tree that can handle strong winds and isn’t bothered by any pests or diseases. They enjoy lots of organic matter as do all dogwoods. Many people think of dogwoods as an understory tree but this location is often too shady. Grow them in a full or partial sun location that gets afternoon shade after 4pm. Add a couple of extra drip emitters or inline drip tubing to your irrigation system and they’re happy.

cercis_Ruby_Falls.1600
Ruby Fall redbud

Besides enjoying the hundreds of blooming dogwoods, I learned about a redbud that is not as fussy as the lovely Forest Pansy. Ruby Falls and Merlot promise to be more reliable in the garden and more heat resistant.

Jon will try his hand growing just about any plant that he thinks others will also enjoy. A fine crop of Alice oakleaf hydrangea grew near a block of Michelia ‘Inspiration’ getting ready to flower and scent the air. The lilacs had finished blooming but the peonies were just starting their show. Jon shared a tip about tree peonies he learned recently from a well-seasoned Japanese gardener. He followed her advice and cut back the tree peony stem in the dormant season forcing it to produce new stems. Voila- they are now loaded with flowers.

peony
peony

Jon grows many other types of dogwood and also Copper beech, magnolia macrophylla, Royal Raindrops crabapple , Sheri’s Cloud nyssa and even a Purple-leaved hazel. I could only fit a couple of 5 gallon cans in my car so a beautiful smoke bush in full bloom and a Black Lace elderberry now call Bonny Doon home. But I have my eye on one of those spectacular Mountain Moon evergreen dogwoods for the back garden.