If needed, tree support can be provided by staking, which stabilizes the root ball and supports the tree until it can stand alone. Over time, stakes and ties should be progressively reduced in height to a point where the trunk does not bend when unsupported. This adjustment should occur after the tree is in full foliage (bare trees may appear sturdier without the weight of foliage). Bare root trees, which are grown in nursery fields rather than in containers, may not require staking. With a few exceptions, most trees will be properly developed within two seasons and able to stand without staking. Often, short stakes (18″ – 24″) without ties are left or placed around the tree to protect against mechanical damage from mowers and string trimmers.
Pruning and Training
Proper pruning is essential to ensure a structurally strong, attractive, and mature tree. Pruning needs vary by species and not all trees should be pruned in the same manner. Generally speaking, creation of a main stem or leader is desirable, with the scaffold branches spaced vertically and radially on the trunk. This spacing also varies by species: medium sized trees should have 6″ – 8″ between permanent limbs, while large trees should have at least 18″ of vertical separation. When removing a branch, the pruning cut should be in branch tissue just beyond the bark ridge and the collar. Normally, limbs being removed will be smaller in diameter than the main trunk or parent branch to which they are attached.
If your new tree is planted in a lawn, keep turf cleared at least two feet from the trunk. Regular lawn irrigation may supply enough water for young trees, however check the tree in between waterings to make sure it’s not wilting. If it is wilting, water deeply once a week in addition for the first few months. Use caution not to over-water or over-saturate the soil, as this may cause root rot.
Watering is generally not necessary during wet winter months. In spring, wait to begin watering until 3-4 weeks after new growth begins. This will encourage deep root growth by avoiding the over-saturation of surface soil. As the weather warms, water weekly for two months and then every two weeks for the rest of the dry season. Irrigating once every 2-3 weeks the second and subsequent years should be adequate. Remember to increase the amount of water, while watering on a less frequent schedule as the root system develops.
Eliminate competitive grasses, weeds, and ground cover within 12″ of the trunk.
Maintain 3-4″ of mulch around the base of the tree, but not against the trunk where rot can occur.
DO NOT use string trimmers near trees/trunks — it can be lethal.
Remove or shorten vigorous shoots along the trunk, but maintain small branches to strengthen the trunk and protect it from sunburn and vandalism.
Inspect regularly for insects and disease.
Ensure your tree is still properly staked.
Trees usually respond only to nitrogen (N); additional fertilizers are needed only if other deficiencies have been identified. Ammonium sulfate with 20% N generally will provide the necessary requirements when spread evenly above the root zone: 2nd year – 1/2 cup (*); 3rd year – 3/4 cup; 4th year – 1 cup. (*) or equivalent amount of nitrogen (N), e.g. 1/4 cup urea (40%N)
Pull mulch back to fertilize. Replace after application.
Larger tree canopies yield greater benefits. Cities can maximize the benefits of trees by selecting the largest canopy tree for the available planting space. The surface area of a tree’s leaves covers between 2 and 8 times the area directly covered by the tree. As a result, larger tree canopies result in improved air quality, cooler summer air, greater reduction of storm water, better water quality, and reduced demand for summertime peak electricity.
100 trees remove 5 tons of CO2 and 1,000 lbs of pollutants per year.
Water Quality and Runoff
100 trees save $550 annually in storm water infrastructure costs.
Shaded pavement can last 50% longer before needing resurfacing with slurry seal. This saves our communities $30,000 per mile in road resurfacing costs.
Cars in shaded parking lots release 18%-21% less hydrocarbon emissions due to heat-induced leakage. Cabin temperatures are up to 60 degrees Fahrenheit lower.
From: E. Gregory McPherson, James R. Simpson, Paula J. Pepper, Qungfu Xiao, Guidelines for San Joaquin Valley Communities, March 1999
Plants in parking lots have been traditionally used for aesthetics and traffic guidance. Regulations generally mandate the quantity and distribution of plants, including trees, based on the size of lots. Increasing emphasis is placed on the ecological services and benefits of urban vegetation, a trend that can be seen in laws regarding parking lot trees. Davis, a small city about 20 miles west of Sacramento, California, was one of the pioneers of parking lot shade regulations. Davis’ ordinance requires that all parking lots be 50% shaded by tree canopy 15 years after development. Although the regulation has been in place for nearly 40 years, there are been no enforcement of shade coverage. The city partnered with Tree Davis to monitor parking lots in 2006 and 2007, but the project was terminated soon after due to budget cuts. In 2013, a Tree Davis intern revisited parking lot shade regulations in Davis as well as other cities in the U.S. The report titled “Parking Lot Shade Regulations: Review and Recommendations” is a summary of that work.
On May 4, Tree Davis volunteers working with volunteers from Pacific Gas and Electric and planted 61 trees back into the neighborhood. The trees picked included crape myrtle, chitalpa, dwarf purple pony, red oak, and blue oak. These trees were picked because they do well in our climate here in Davis and chitalpa, crape myrtle, and dwarf purple pony will grow to a mature height of 15-20 feet leaving clearance under the high voltage power line. Additional red oak and chitalpa were planted along the bike path in front of Nugget.
As part of PG&E’s annual routine work, trees on both private and City owned property along both sides of Claremont Drive that were potentially causing a public safety hazard under a 115kV transmission line have been removed. In the past these trees have been topped, which is a poor arboriculture practice. Trees need space to grow both above and below ground. PG&E asks customers to carefully consider their surroundings when planting trees using “Right Tree, Right Place” methods. Proper selection of trees under or near power lines reduces fire hazards, limits the need for frequent pruning, increases property value and adds beauty to the community. It is recommended that customers choose a tree and location where the ultimate height and spread of the tree will grow no higher than 15 feet tall so the tree will not grow into or interfere with the power lines. Further, the location of underground facilities should be considered as roots may be damaged if underground facilities need to be dug up for maintenance or repairs. To ensure each property owner is able to fully enjoy their newly planted tree PG&E recommends a consultation with a PG&E arborist.
Eight Tree Davis volunteers planted 50 valley oak trees on Saturday, March 16th in honor of Arbor Day. The plantings were done in conjunction with the Russell Blvd. Tree Project which has planted over 400 trees along the Russell Blvd. bike path west of Davis since 2009.
Funding for this planting was provided to Tree Davis by the Sacramento Tree Foundation as part of its California ReLeaf 2013 Arbor Week Tree Planting Grant Program which is done in cooperation with the Department of Forestry and Fire Protection.
The trees were donated by the L.A. Moran Reforestation Center on Chiles Road in Davis which is managed by Rich Marovich, the Streamkeeper for the Lower Putah Creek Coordinating Committee.
The holes were dug ahead of time by volunteer Dan Garrett of Garrett Landscape Construction, who donated the use of his company’s Bobcat auger.
The water was provided by Phil Kitchen of Three Palms Nursery, which is located near the plantings at the junction of County Road 95 and Russell Blvd.
Many passersby on the bike path have voiced their appreciation to the volunteers as they plant the trees, which is so very nice” reports Janet Mercurio, Coordinator of the Russell Blvd. Tree Project. “But some people have also voiced concern about the trees that are planted directly under the utility lines. I clarify for them that the lines are only telephone lines and not electrical lines, so there is no problem. The telephone company allows trees to grow right through the phone lines with only occasional minor pruning needed.”
Tree Davis and the Russell Blvd. Tree Project are hoping to plant another 36 trees this fall to complete the plantings along the Russell Blvd. Bike Path.
Twenty-five Tree Davis volunteers came together today to plant 10 donated trees at Davis City Hall, one of many events taking place in celebration of California Arbor Week (March 7-14), a statewide initiative led by California ReLeaf. Tree Davis is a member of California ReLeaf’s network of nonprofit and community tree planting groups committed to increasing green spaces in their communities.
“We’re glad we could plant these trees today and as a result improve the air quality and tranquility of the area,” said Keith McAleer, Executive Director of Tree Davis. “California Arbor Week is a great opportunity for individuals and organizations to not only plant trees but also raise awareness about the important benefits trees have in our lives and our communities.”
In addition to today’s event, the City of Davis is celebrating its 35th year as a TreeCity USA, making it the second longest running TreeCity USA in California. TreeCity USA cities follow established urban forestry management standards such as having a tree commission and celebrating Arbor Day. Tree Davis and the City of Davis will continue to celebrate this honor by planting more trees to celebrate national Arbor Day in April.
“We were fortunate to be able to provide nearly $35,000 in funding to organizations this year for urban forestry projects and anticipate that thousands of trees beyond those funded will be planted throughout the state,” said Joe Liszewski California ReLeaf executive director. “We work with local organizations like Tree Davis that understand the specific urban forestry needs in their communities and help us achieve our ultimate goal to preserve and enhance California’s urban and community forests.”
California Arbor Week runs March 7-14 every year to mark famed horticulturist Luther Burbank’s birthday. This year, legislation was proposed to define California Arbor Week in statute. Visit www.arborweek.org for more info.
Tour downtown Davis on this fun, informative Tree Walk!
Learn about some of the oldest, biggest, and most interesting trees in downtown Davis. Start at the Tree Davis leaf emblem sculpture at 2nd St. and D St. Pick up a guide at the kiosk or come prepared by downloading and printing your own guide here.