Adding a tree to your landscape is like making an investment, choose a good one and it will grow and provide shade and beauty for your family for a long time. But choose the wrong one and you may be battling surface roots, smelly flowers, brittle wood, excessive litter or pest problems. So many possible trees, where do you start? Recommended Trees Fall 2016
How big should your tree be? The first step should be to decide the mature size of the tree. Trees generally fall into four sizes: tiny (up to 15′ tall and wide), small (20-30′ tall and wide), medium (35-50′) and large (50′ and taller). Look at your landscape and estimate the size of trees that will be right for you.
- How much shade you want for a patio or outdoor living area. A hot, west facing patio will not be comfortable on summer afternoons without shade.
- Shade the house, on the east and west sides of the house to keep hot summer sun out of the house. South facing windows should be shaded in the late spring through early fall, but unshaded during the winter to absorb the warming sun. Deciduous trees can be chosen to provide this shading. Much of the heat that enters buildings comes through windows, so pay attention to shading them. Keeping the house cool can markedly reduce your air conditioning and your electric bill.
- Shade over the driveway or parking area keeps parked cars cool, this shade helps preserve the paint and interior of the car and keeps the occupants comfortable. Parking in the shade helps improve air quality by minimizing fuel evaporation and reducing the air conditioning needed.
Trees need room to grow, both above the ground and below.
- Foundations of buildings, patio, pool, walkways, driveways, roads and sidewalks do not benefit from large tree roots growing into or onto them. Recommended clearances are included on our tree pages.
- Solar collectors need maximum sun to work the best, if you are adding trees near a solar installation, be sure that they will not shade the collectors when the trees mature.
- High voltage power lines (the ones on the tops of the power poles which are uninsulated) must have clearance from tree branches to avoid dangerous situations. The electric utility will prune trees that are too close to power lines, but the resulting shape of the tree may not be what you had in mind. The power “drop” and telephone lines to the house is insulated and can be in contact with foliage. Obviously, a large branch falling on the lines would break them though.
- Transformers or other ground level electric equipment must be kept clear from so that work can be done safely. Contact your electric utility to find out the required clearances.
- Many newer homes and buildings have underground utilities which may affect tree placement. We suggest you avoid planting directly on underground lines because if the lines needed to be repaired, the tree might have to be removed. Most underground utilities are 2-4′ deep, and well-sealed from root invasion. Older sewer lines may leak at joints and may allow roots to penetrate, so consider keeping trees away from them. You can find out where your underground utilities are located by marking possible tree locations using white paint or white flags, then contacting USA (Underground Service Alert, call 811 ( 800/227-2600 or http://www.usanorth.org/). Within 2 business days, the utilities will come out and mark the locations of underground utilities with paint or flags.
Deciduous or Evergreen? Deciduous trees drop their leaves in the winter which does leave you with a raking chore for a few weeks in the fall. Without leaves, the trees allow the winter sun in. Evergreen trees keep their leaves on all year so it will always be shady under their canopy. Evergreen trees do shed their leaves though, a few a day usually, so you will have a clean-up chore. Evergreen trees may have needles, like pines or Coastal Redwoods, or broad leaves like Magnolia or Camphor trees.
Fall color, flowers, fruit or seeds? Usually these features are a welcome addition to the landscape, but think about what you like.
- Many deciduous trees develop yellow, red or orange leaves in the fall. This usually lasts a few weeks before the leaves drop and may vary in intensity depending on weather and type of tree.
- Showy flowers on trees are often welcome. Trees like Flowering Plums, Crabapples and Magnolias have very showy flowers that last for 1-3 weeks. Other trees, like Birches, Maples and Oaks, have inconspicuous flowers. A few, like the Little Leaf Linden are fragrant.
- Fruit and seeds can be a desirable feature, think of a ripe, tasty peach in the summer or bright red crabapples decorating the tree in the winter. But most every tree will make some sort of fruit or seed. As you can imagine small, dry fruit or seeds will be easier to clean up. Some trees, like Chinese Pistache, Tupelo or Ginkgo are entirely female producing seeds, or male producing pollen.
How much water will the tree get? In our climate, most trees will need water in the dry season to keep them healthy and vigorous. Think about how much irrigation water is applied to the area and choose a tree that matches.
- High water areas like lawns receive frequent irrigation. Red Maples, Coastal Redwoods, River Birch, Tupelo are all trees that will be happy in high water areas.
- Moderate water is the level of that most conventional landscapes receive. Most nursery plants and trees are adapted to this level. Some examples are: Crabapples, Japanese and Trident Maples, Dogwoods, Eastern Redbuds, and Flowering Pears.
- Low water, “Waterwise” or “Xeriscape” landscapes receive lower amounts of irrigation. Some trees that do well in these water saving situations are Chinese Pistache, Goldenrain Tree, and Hedge Maple.
- Very low water is just natural rainfall. Our California native oaks are good options for areas that will not be irrigated. They are tough trees that are adapted to this situation and grow best in it. You will need to provide some irrigation to get them started for the first few years.
What about trees that attract pests? Some trees are known for having pest problems in our area and we suggest you minimize or avoid them. Japanese White Birch and Raywood Ash are two that have serious pests in our area that can severely damage or kill them. We suggest you avoid or minimize their use. Most trees may occasionally be attacked by pests, but not enough to severely damage them. Having different kinds of trees in your landscape will help prevent severe pest problems because pests and diseases often are specific to a type of tree.
How can I avoid a “weed” or “junk” tree? Some trees are not suitable for developed landscapes, their growth may be too vigorous or they may have invasive or surface roots or reseed vigorously. Examples include trees like Glossy Privet, Box Elder, or Chinese Tallow tree. Others, like the Purple Robe Locust grow so fast that they tend to split and break before they are mature. We recommend that you avoid these trees. Some trees are fine for a large property where they can be far from the house, but due to weak wood, should not be planted near buildings. Weeping Willow and Silver Maples are examples.
I need trees that grow fast. We are all anxious for our new trees to grow up to be their mature size very quickly. But choosing a tree just because it is fast growing can lead to problems. Very fast growing trees tend to have weak wood, poor structure and may be susceptible to pests and diseases because they put their energy into growth and not strength or pest resistance. Some examples are Willows, Silver Maples and Purple Robe Locusts. Other fast growing trees will eventually grow too large for most landscapes, Coastal Redwoods grow to be over 200′ tall when mature.
Choose trees that will last a lifetime and be the right tree for the location in your landscape. Look at their characteristics and choose ones that have the most desirable features while minimizing the least desirable ones.