Monthly Archives: July 2021

Nathan’s Best Picks for Columnar Street Trees

By Nathan Lawrence—ISA Cerified Arborist, OSU Master Gardener and owner of Good News Tree Service, Inc. at in Wilsonville, Oregon

The following is my list of the best street trees for small front yards that have space for only narrow, non-spreading street trees. All of these trees grow well in the western valleys of the Pacific Northwest, are not messy, and have little or no problems with diseases based on my decades of experience as a tree care provider and plant health care expert. You can search online for photos of these trees to see what they look like.

  • Dogwood—Hybrid White Dogwood (Cornus ‘Eddie’s White Wonder’): This unusual hybrid is a cross between our native Western dogwood, Cornus nuttallii, and the Eastern North American species, Cornus florida. The large (four inch diameter), bold flowers open in early spring and have broad overlapping bracts (false petals) that are gleaming white and abundant against a dark green foliage making for a striking display. The tree has a narrow, upright and rather pyramidal in form, with slightly drooping branching. It has shown resistance to dogwood anthracnose, a common foliage disease. This tree grows to height of 20 to 30 feet and a width of 15 to 20 feet. The leaves turn reddish pink in the autumn and small red berries decorate its branches in the winter. The tree can tolerate full sun to partial shade.
  • Dogwood—Starlight Dogwood (Cornus x nuttalii ‘Starlight’): A close relative to Venus is the variety Starlight® which is the result of crossing Korean dogwood with the Pacific dogwood. 35 feet high and 20 feet wide Resistant to anthracnose. Abundance of 4-5” creamy white flowers create a showy spring display against its deep green foliage. Orange strawberry-like fruit in early fall, followed by a show of red fall color. Resistant to anthracnose. Full sun to partial shade; size 25-30 feet tall by 15-20 feet wide.
  • Ginkgo—Sky Tower Ginkgo (Ginkgo biloba ‘JN9 Sky Tower’): Rich green foliage. Narrow crown. Brilliant yellow fall color. Height 20 feet by 6 feet wide. Make sure you plant only male trees. Female trees produce a messy and nasty-smelling fruit.
  • Hornbeam—American Hornbeam (Carpinus caroliniana): This North American native grows to about 30 feet tall and 20 feet wide. It is slow-growing, deciduous, small to medium-sized with an attractive globular form. It prefers moist soil and is not drought tolerant.
  • Hornbeam— (Carpinus Lucus pyramidal): Narrow, slender growing habit. Dense canopy. 16 to 18 foot height. Attractive yellow, green catkins in the spring.
  • HornbeamUpright European Hornbeam (Carpinus betulus ‘fastigiata’): Dense green foliage with golden fall color. Height 40 feet and width 20 feet.
  • Maple—Crimson Sentry (Acer platanoides ‘Crimson Sentry’): This tree grows to a height of 25 feet and width of 15 feet. It has purple leaves, which turn maroon to reddish bronze leaves in the fall. Oregon State University says of this tree, “In western Oregon the trees appear rather susceptible to powdery mildew, a fungal disease. This is especially noticeable in mid-to-late-summer. The affected leaves become a dull maroon color followed by a white-gray color, as if dusted with powdered sugar. One authority suggested that Crimson Sentry™ should not be recommended for mass or street plantings ‘unless a ghostly pallor on purple foliage is actually wanted.’”
  • Maple—Karpick Red Maple (Acer rubrum ‘Karpick’): This columnar red maple grows to a height of 45 feet tall and 20 wide with red-orange foliage in the fall.
  • Oak—Columnar English Oak (Quercus robur ‘Fastigiata’) and Crimson Spire Oak (Quercus robur x Q. alba ‘Crimschmidt’): These trees are slow to moderate growing reaching a height of 50 to 60 feet tall and 15 to 20 feet wide. They prefer full sun and well-drained soil. They are extremely adaptable and very tolerant of urban conditions. The trees tolerate drought, but do best with occasional irrigation.
  • Oak—Pacific Brilliance Pin Oak (Quercus palustris ‘Pacific Brilliance’): The crown height is 50 feet and the crown spread is 20 to 25 feet at maturity.
  • Paperbark Maple (Acer griseum): This tree grows to a height of 20 to 30 feet and width of 12 to 20 feet. Its crown is oval to oval rounded. Tree is noted for its unique copper orange to cinnamon reddish brown peeling bark and its showy orange to red colored leaves in the fall.
  • Stewartia—Japanese Stewartia (Stewartia pseudocamellia): This slow-growing tree grows to crown height of 12 to 40 feet and a crown spread 10 to 25 feet with white camellia-like flowers that bloom in the late spring. Several smaller varieties of stewartia are available too (e.g. Korean stewartia [Stewartia koreana] and tall stewartia [Stewartia monadelpha]).
  • Tupelo, Afterburner (Nyssa sylvatica ‘David Odom’): This tree grows moderately fast to a height of 35 feet and a crown spread of 20 feet. The shape of its crown is upright and pyramidal to oval and is symmetrical and uniform. Its high gloss foliage is bright green tuning bright red in the fall. It has a blue-black berry-like fruit that’s less than a half-inch in size.

July in the Garden—A To Do List

This guide is tailored for the western valleys of Oregon and Washington. 

YOU can help to make the world a better, a more friendly, loving and beautiful place by being a good steward of the spot on this earth that you are privileged to be borrowing for a time—your garden. Nathan, the Treevangelist, urges you to treat your spot on this planet like your own personal Garden of Eden paradise. Then notice the joy that it will bring to you! This is your Divinely mandated responsibility.  Your trees, shrubs, flowers and the wildlife in your yard will express their smiling appreciation back to you as they radiate love , joy and beauty bursting forth with vibrant and verdant life. Here is a to do list to help you to do just that…

Wow! June ended with a bang a few days ahead of July’s Independence Day celebrations with its record high temperatures of 110 to 120 degrees in our region. Temperature records were not only made, but shattered to smithereens! We’ve never seen anything like it, and neither have the plants. Despite our most valiant efforts, some of us lost some of our green friends. At my house we had three days of triple digit temps: 106˚, 111˚ and 115˚. The more tender plants in region just refused take this heat. A few succumbed to it while many suffering heat stroke.

The climatological extremes this season have been off the charts with record ice from freezing rain in February to record high temps in June. Our tree service is still cleaning up from the epic, 150-year ice storm event of February 12, and now the summer heat, which has started a whole month early is upon us. What more can be said? If you want to keep many of your plants alive, plan on budgeting more money for your water bill.

Beyond all the aforementioned seasonal weather anomalies, in July as Americans, we celebrate our independence from extreme and overreaching  governmental tyranny as well as our liberty and freedom to pursue our happiness, to speak freely and practice our beliefs and religions according to the dictates of our own individual conscience without fear of others fascistically imposing their beliefs upon us.  To be sure, our freedom and liberty from oppression is a God-given blessing that most other countries don’t have!

In a similar though slightly oblique vein, in the garden, our plants have a celebration of their own going on as they declare their freedom to express their full potential as they burst forth with a panoply of starburst blooms of all shades of red, white and blue. The photo above is a montage of flowers from my own garden.

Let’s all rejoice along with our flowers and be thankful for the blessings that we have of living in the greatest nation on God’s green earth! As one person recently said in light of current negative events rocking the U.S. and the world, it is all too easy to focus on the weeds in the garden instead of on the beautiful flowers, vegetables along with the trees and shrubs. Let’s all work together at pulling the weeds out of our own personal garden without destroying other people’s gardens along with all the other good plants that are out there! Those who are  wise among us will ponder these words and will work to be part of the solution rather than part of the problem, that is, without destroying the whole garden of our society in the process.  — Nathan, the Treevangelist

Readers’ suggestions on how to improve this list are gladly solicited. If you, the reader, have any suggestions for additions to this month’s list, please put them in the comments section of this article, and I will add them to the list. Thank you in advance! — Nathan

Tree and Shrub Care

  • Birch trees: Thanks to the bronze birch borer beetle, a large number of the Pacific Northwest birch trees are dying. To make your tree less hospitable to this nasty and lethal pest, there are two inexpensive things you can do. First, apply several inches of mulch to the ground under the canopy of your birch tree. Second, with a whirly bird sprinkler, irrigate the area under the birch’s canopy. The more water the better, since birches are water-loving trees. Irrigate once a week for several hours during warm weather and twice during hot weather. These two actions will lessen the chances that the beetle will attack and kill your birches. The bronze birch borer beetle can be treated in the late spring, but treatments are expensive. Call GNTS. Inc. for more info.
  • Dogwood trees: Monitor leaves for signs of anthracnose. (See more info below.)
  • Hedges: Shear after spring growth and before hot weather. Shearing during hot weather may result in sun scald of newly exposed under-foliage.
  • Maples (including Japanese maples): Monitor the leaves of all maples and other trees and shrubs for symptoms of the potentially lethal verticillium wilt fungal disease. If you see branch dieback, call GNTS, inc.
  • Mulch: Apply two to three inches of mulch around all trees and ornamental shrubs. This helps to fertilize the plants and feed the soil, and also protects them against weed growth and loss of water when the warmer  weather returns.
  • Pine tree pruning: Don’t do major pruning of pine trees during the growing season, since this attracts sequoia pitch moth infestation.
  • Pruning of trees and shrubs: You can do all aesthetic pruning of all ornamental shrubs and trees (except pines) at any time of the year including summer. Don’t over-prune the top crowns of thin barked trees (e.g. Japanese maples, flowering cherries), since the sun’s UV rays can cause trunk and branch bark dessication resulting in cracking and dieback of sapwood and even heartwood resulting in entry points for diseases and potential structural failure of branches and trunks.
  • Be careful not to do major pruning during periods of hot weather, since doing so exposes tender leaves underneath that haven’t acclimated to the sun’s ultraviolet rays yet, since they have been shielded by the layer of leaves you’ve just removed by pruning. Sun scald of these tender leaves may occur, especially on southern and  southwestern sides of the plant. Sun scalded leaves won’t kill the plant, but it looks unsightly and diminishes the plant’s ability to photosynthate (produce food for itself).
  • Pruning of large trees: Most trees in the temperate western valleys of Oregon and Washington can be pruned anytime of the year. If you’re not sure what to do, or how to do it, call Good News Tree Service, Inc. for a consultation, pruning lessons or to have them do the pruning for you. It is likely best to wait for cooler weather to prune stressed or sick looking trees. Call us if you have questions about this.
  • Prune fast growing ornamental shrubs (e.g. laurel, privet, photinia, laurustinus, barberry) that are beginning to look shabby. You may need to prune them again in the early summer for a more neat and manicured look. 
  • Tree and shrub removal and stump grinding can be done all year long. 
  • Trees: Have an ISA Certified Arborist with an ISA Tree Risk Assessment Qualification (like Good News Tree Service, Inc.) inspect your large trees for the potential of failure due to weak root systems and defects in trunks and branches. This can be done anytime of the year.
  • Conifer trees that are drought stressed: The Willamette Valley remains in a severe drought. Large native trees (e.g. Douglas-fir, western redcedar, spruce, native firs) are getting stressed and some are dying. If you have a tree that is showing signs of drought stress (e.g. pitch globules exuding from the bark, excess needle drop, yellowing of foliage), then you need to water your tree to save it, or pay the high price to have it removed after it has died. With a whirlybird, impulse or similar sprinkler or soaker hose, saturate the soil under the tree out to the tree’s drip zone (i.e. the outer tip of tree’s crown) for several hours once or twice a week to achieve deep root watering. Typical lawn irrigation systems don’t put out enough water to adequately irrigate the deeper roots of a tree, so don’t rely on your irrigation system to proved the water that large trees need to survive.

Plant Health Care

  • Watering trees and shrubs: During the hot summer months, well established trees and larger ornamental shrubs need little or no watering. However, newly planted trees and shrubs will need watering for the first two to three summers until their roots get established. Regular lawn irrigation isn’t sufficient to give trees and shrubs the deep watering they need to survive the summer heat. During warm weather, deep water your new plants at least once per week. During hot weather, twice per week.
  • Deep Root Fertilization: Don’t do so after the weather becomes too hot. Fertilizer will push out new growth, which will likely scorch in sun. This is a waste of fertilizer and plant resources.
  • Dogwood Anthracnose: If you missed the spring sprays topical fungal sprays,  and you see signs of anthracnose on your tree’s leaves (reddish, purplish, brownish splotches), you can spray your trees with a basal bark fungicide. Call GNTS, Inc. for information on this treatment.
  • Monitor trees and shrubs for insect pests: Piercing and sucking plant pests (e.g. aphids, lacebugs, scales, weevils, mites, etc.) are now out and active. If major infestation occurs, plan a course of action to treat your trees and shrubs against these pests. Small numbers of piercing and sucking insects are not harmful to plants. In fact, they provide food for the beneficial, predatory insects that feed on them. To control harmful insects, one can apply systemic insecticides against piercing sucking insects (aphids, lacebugs, scales, weevils, etc.) via soil injections (one treatment gives season-long control). If applied according to label directions, this will kill only the harmful and not beneficial insects.
  • Spider mites will start to become active as the weather warms. Systemic insecticides are available against this pest.
  • Tent Caterpillar: Apply systemic pesticide for season-long control.
  • Verticillium Wilt: You can still treat trees for this soil born fungal pathogen during the summer, but fall is the best time to treat, and spring is the second  best time. Maples are especially plagued by this disease. During hot weather, symptoms include smaller than normal cupped leaves in the upper canopy, often with the death of the entire branch occurring.

Elsewhere in the Garden

  • Slugs and snails. Put slug bait around your flowers and tender perennials like hostas. 
  • Mulch. Apply two to three inches of mulch (e.g. bark dust, garden compost or wood chips) on all of your shrub beds. Covering bare dirt areas in your yard with mulch helps to prevent soil compaction from rains, and weed growth, and helps to enrich our heavy clay soils.
  • Flowers. Continue planting annual and perennial flowers. Water and fertilize annuals and perennial flowers. The hotter the weather, the more water they will need. Flowers in pots and hanging baskets dry out especially quickly, and so need watering every day or two.
  • Ivy. Cut English ivy off of the base of trees. (This can be done any time of the year.)
  • Backyard birds feeding. Don’t stop feeding the birds even during the spring and summer seasons. Dutifully maintain your bird feeders. Why? Even though we’re now past the winter season and there is more food available for the birds, having these feathery friends frequent your garden serves several purposes. First, they bring life and excitement to your backyard by turning it into a bird sanctuary. Second, your singing friends will thank you for your generosity by providing you with hours of entertainment, and by eating insect pests that harm your ornamental trees and shrubs. So bring life and excitement to your backyard by turning it into a bird sanctuary. Don’t forget to keep bird baths full. In hot and dry weather, birds need water to drink and to bathe in.
  • Vegetable garden. Start making plans for your vegetable garden. Once the soil has dried out, you can begin working it for planting our veggies. Usually this will occur in late April or early May and sometimes later depending on the weather. The earlier you plant, the sooner you’ll be feeding on delicious veggies from your own garden! 
  • Planting trees and shrubs. This is a good time of the year to plant trees and shrubs. Visit your local nursery and select your favorite ornamental shrubs and shade trees. After planting your new shrubs, just make sure that you water them well immediately and regularly subsequently for the first two or three summers until their roots get established. During warm weather (in the 60s to low 80s), deep root water once per week. During hot weather (mid-80s and higher) deep root water at least twice per week.
  • Fertilizing shrubs. Fertilize your ornamental shrubs with a slow release fertilizer. If the shrubs have a layer of barkdust or other mulch around them, rake the mulch away and apply the fertilize to the bare dirt, so that it actually reaches the plant’s root zone.
  • Water and fertilize annuals and perennial flowers. The hotter the weather, the more water they will need. Flowers in pots and hanging baskets dry out especially quickly, and so need watering every day or two.

Rose Care

  • Dealing with rose pests: Spray or treat roses with a fungicide as needed preventively to insure protection against fungal pathogens such as black spot, powdery and cottony mildew, rust and spot anthracnose. Apply a fungicide only after the rose has put out several inches of new growth. Excellent choices of both organic and inorganic fungicides are available at your local garden center or nursery. Some fungicides require spraying in the early spring as the new growth is emerging. Major plant pests include mites, aphids, thrips, rose slugs, leaf rollers, rose midge, spittle bug and sawfly. Determine what pest or disease your rose has, do some research online if necessary to ascertain this, and then visit your local garden center or nursery to find the right product for the job. Always read and follow all label directions. It’s the law! 
  • Late spring, summer and into early fall: During prolonged warm, dry weather, deep root water your roses at least once a week. A rose needs five gallons of water per plant per week.
  • As needed, remove spent flowers after they are done blooming.

Summer Lawn Care

  • Summer lawn maintenance. Summer is about mowing, watering, and pest control. Stay on top of mowing for a healthy lawn.
  • Irrigation. Water deeply, slowly and as infrequently as possible. Try to avoid watering established lawns more than two or three times per week if possible except during extremely in hot conditions. It is not a bad idea to let the soil under your grass to dry out for a short time in between watering as this forces the grass roots to grow deeper in search of water thus making for a more drought tolerant lawn. It is best not to rely on timers for irrigation as temperatures will dictate water needs in addition to lack of rainfall. However, timers are helpful if you have lawns areas that are to large to micromanage or you will be gone for a period of time. 
  • Mowing. Mow once a week, removing no more than one-third of the height of the grass to avoid stressing it. Mow regularly to prevent weed seed spread.
  • Letting your lawn go dormant. If you want to save on your water bill during the summer months, you can skip watering your lawn if you don’t mind it turning brown. It is not dead; it is merely sleeping or in a dormant state. When the rains start up again in the fall, your lawn will turn green and start growing again.