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CITY OF

PACIFIC GROVE       

New Tree Planting Design Guidelines

How Do Trees Reduce and Remove Pollutants from Stormwater Run-off?
 
Trees and forests improve watershed health primarily by decreasing the amount of stormwater runoff and pollutants that reach our local waters. Trees and forests reduce stormwater runoff by capturing and storing the rainfall in the canopy and 
releasing it into the atmosphere through evapotranspiration. In addition, tree roots and leaf litter create conditions that promote infiltration of rainwater into the soil. 
Trees also help to slow down and temporarily store runoff, which further promotes infiltration and decreases flooding and erosion downstream. Trees and forests reduce pollutants by taking up nutrients and other pollutants from soils and water through their roots, and by transforming pollutants into less harmful substances. 
Additional benefits of trees include: 
  • Improved air quality 
  • Reduced air temperatures in summer 
  • Reduced building heating and cooling costs 
  • Increased property values 
  • Habitat for wildlife 
  • Recreation and aesthetic value 
Tree 1
 
Planning Tree Planting 

Location 
It is important to plan in advance the appropriate location for your tree or group of trees. Please use this checklist to ensure that you comply with the design guidelines for properly locating a tree(s): 

  1. Decide what function you would like your tree(s) to accomplish:
    • Shade a certain area 
    • Provide edible fruit 
    • Provide flowers or aesthetic interest 
    • Screen or frame specific views 
  2. Research the tree’s mature size (height & width) and ensure that it will not outgrow the location that you have intended.If there is insufficient space to allow the tree to grow full size, choose a different site or a small growing tree species. 
  3. Tree planting sites should contain adequate soil volumes to allow root growth. Below ground space requirements should be twice the area of the above ground canopy coverage extents. 
  4. Trees should be located away from overhead and underground utilities. The property owner is responsible for checking location of above and underground utilities before installation of a RainScapes LID Technique to ensure there will be no conflicts with the project. Contact “Call before you dig!” 811 hotline to locate underground utilities. 
  5. Tree planting sites should allow adequate distance between the tree trunk and the hardscape elements that may be damaged by root development. Determine an adequate distance based on the mature growth characteristics of the tree. Root barriers are recommended for trees planted within 5 feet of foundations, walls, or other hardscape features. See ‘Root Barrier’ Section in this document:
    • To be located away from septic systems and wells.
    • To be located away from building foundations.
    • To be located 3 feet from public sidewalks and 5 feet from property lines. 
    • New trees to be located at a safe distance from other existing trees which may have large root systems. 
Tree Selection
Trees can be planted as a beautiful landscape feature and also be functional. Select tree species that are appropriate for your location such as Central Coast California native plants or non-native drought tolerant trees. Species planted in the City of Pacific Grove shall be selected from the list of appropriate landscape trees for Pacific Grove
 
After determining an appropriate tree location from the guidelines above, evaluate your site conditions further to determine an appropriate tree species: 
  • How much sun and shade will your tree(s) receive? Be aware that when planting similar tree species in different locations, the tree exposed to more sun will grow quicker than the other, if placed in a shadier location. 
  • Is the potential tree location exposed to high winds or sheltered from wind? 
  • Is your home located near the coast, within a Coast Live Oak stand, or upland in the Monterey Pine Forest? 
In addition, consider any tree characteristics you would like to have: 
  • Provide flowers, decorative bark or leaves 
  • Provide fall color 
  • Consider tree form such as columnar, vase-shaped, wide canopy 
  • Multi-trunk tree or standard (one straight trunk) 
  • Deciduous or evergreen tree 
  • Consider the required maintenance for future property owners 
Tree Sizes
Tree container and box sizes are controlled by AmericanHort trade association (a consolidation of the American Nursery and Landscape Association and the Association of Horticulture Professionals). To understand the height, width, and tree structure requirements for container and box sizes, see the American Standard for Nursery Stock document
 
Typically the cost varies per the container or box size of the tree purchased at the nursery. Much larger box sizes may need special delivery services. This may also require professional contractor fees for installation. Call the nursery in advance to 
determine costs. 
 
Please note that plant nurseries carry different tree species. Call in advance to find out the availability of the tree(s) you want in the right container/box size, so you can plan for any substitutions that may be needed. 
 
Note:
  • You will be required to submit site photographs of your tree location before installation with your rebate application. 
  • Take a couple photos of the desired location on your property and print. Include your name, contact information, and address where the tree will be planted 
  • Mail with your rebate application

Installation

Tree Pit 
After you have properly located the placement of your tree and have purchased your tree from the nursery, it is time to dig the pit or planting hole. Place the dug soil in a pile as you will use it later as soil backfill. 
 
Depth of Hole:
A firm, flat-bottom hole will prevent the tree from sinking. Dig the hole only deep enough to position the root collar (where the bottom of the stem meets the surface of the soil) even or slightly higher with the landscape soil surface. See Figure 4. 
 
Width of Hole:
Dig a hole twice the root ball diameter. Loosen the soil on the edges of the hole. 
 
Watering Tubes / Irrigation / Hand Watering 
Irrigation or extra hand watering will be needed for tree establishment. Extra water at the time of planting and for a few months after planting will help tease the roots from the root ball into the new surrounding soils. Once the tree is established, irrigation and watering can be limited to the dry seasons of the year. Native trees to the Central California Coast, if planted in the correct conditions/location will need minimal watering throughout the year in addition to a reduced need for pest 
management practices. 
Watering Tubes 

Watering tubes allow water to be delivered directly to the root zone of the tree, encouraging deep roots. Also, it prevents any surface runoff when watering the tree. There are two ways to install watering tubes: 

  1. not connected to an irrigation system, therefore being an aid to hand watering, and
  2. connected to an irrigation system. 

If you are unsure how to incorporate an irrigation system into a design, consult with an irrigation specialist or licensed landscape contractor. 

For setting up a watering tube for hand watering purposes, place a 4 inch by 24 inch watering tube (PVC Pipe or Perforated PVC Pipe with perforations set next to root ball) set flush at the finished grade of soil. See Figure 1. The tube should be open on the bottom end and filled with loose gravel. The top of the tube should be covered with a cap. Two tubes can be installed on opposite sides of the root ball. The application of water through the watering tube should only be done after the tree is established (one to two growing seasons/18-24 months). Installation of the tube is important at the time of planting so roots can grow around it. 

Tree 2

FIGURE 1: A drawing showing the proper position of a watering tube for a tree. 

Watering tubes can also be incorporated into an existing irrigation system or become a part of a new irrigation system. See Figure 2 for an example of such a system. 
 
Tree 3
FIGURE 2: Irrigation Watering Tube Example from Rainbird, RWS Root Watering System. Intended to be incorporated into an new or existing irrigation system. 
 
Drip Tube Irrigation 
If your soil is pure sand, the infiltration rate of the water will flow too fast and will not reach the tree’s root system effectively. If this is the case, drip tube ring(s) is recommended. Multiple emitters around the root ball deliver water slowly to the roots. This system is indented to be connected to an irrigation system. Emitter spacing and flow rates vary per manufacturer. Research and follow manufacturer’s recommendations. If you need further assistance contact an irrigation specialist. See 
Figure 3. 
Tree 4

FIGURE 3: Example of drip Tube Installation around tree. Note that drip tube is to be properly staked and covered with mulch so it is not visible. Follow manufacturer’s 
recommendation for drip tube layout and installation. 
 
Root Barrier
If you need to locate your tree within 5 feet of a building foundation, wall, or other hardscape surface, a root barrier will need to be installed to redirect roots down, away from hardscapes that you want to protect from root damage. There are many 
kinds of root barrier products for various scenarios. Follow the manufacturer’s recommendations of the product you choose. 
 
Planting 
Remove soil and roots from the top of the root ball to expose the root collar. Cut away any roots that grow over the collar. Also cut any roots that circle or mat along the sides and bottom of the root ball. The root collar should be even or slightly 
higher with the landscape soil after planting. Set the tree so it is centered at the bottom of the hole. See Figure 4. 
 
Soil Backfill
Fill the hole with soil backfill to promote rapid root growth and quick establishment. Soil backfill is the existing soil that was dug from the tree pit. Apply in 12 inch lift, packing the soil and/or watering around the tree to remove any air pockets. Set 
watering tubes if applicable. Create a water basin to hold water around the outside of the root ball. See Figure 4. Hand water each plant thoroughly after planting. 
Adding fertilizer or soil amendments is not recommended as most nursery-grown trees are well fertilized during production and seldom respond to fertilizing at planting except in the most infertile soils. 
 
Tree 5
FIGURE 4: Proper planting of a landscape tree. (From University of California Agriculture and Natural Resources, Publication 8046, Planting Landscape Trees) 

Pruning 
The less a young tree is pruned, the more total growth the tree will make. However the growth may not be where you want it or where it will develop the most desirable tree structure. After planting, remove broken, dead, or diseased branches and branches that interfere with more desirable placed ones. 

 
Tree Staking & Wind Screens
Staking holds trees erect and allow the root ball to anchor. Secure the trunk at the point where the tree stands straight. There are various methods to stake a tree based on the landscape situation, tree height, and form (multi-trunk or standard). 
Stakes are not necessary if trees can stand by themselves or planted where little or no protection is needed. Consult with a landscape architect or licensed landscape contractor for advice. If the tree is exposed to wind, a wind screen may need to be erected as the tree becomes established. See image below.
 
Tree 6
 
Mulch
Mulch is a protective layer of material spread on the top soil. Mulch keeps the soil moist, replenishes organic material in the soil, prevents erosion, and discourages weeds. A 2-3” layer around the tree is recommended, however, remove bark away 
from the tree collar location. See Figure 4.
 
Deer Deterrent 
If you don’t have deer fencing erected around you property, you may want to consider a deterrent method to keep deer from eating the leaves and stems of your new tree. When trees and plants come from a nursery they are lush and extremely appealing to deer, even if the plant is known to be “deer resistant”. As the tree grows taller, larger, and more woody, it will become less tempting to deer. However, if deer are hungry and have a difficult time finding food, especially in times of drought, they are most likely going to nibble on the lower leaves of your tree. Temporary fencing or environmentally friendly deer repellents are recommended at the time of planting and during times of drought. 
 
Maintenance 
  • Trees require regular landscape maintenance and each tree species has specific needs. Research the tree species and required maintenance to ensure you are providing the right care. 
  • After planting, check around the tree for weeds and pull immediately. 
  • Avoid using synthetic fertilizer or herbicides around your tree because these chemicals are pollutants. For preferred alternatives, see Monterey Regional Stormwater Management Program and Our Water Our World.
  • When the tree has established itself (approximately 1-2 growing seasons), reduce the amount of irrigation and start using the watering tubes if applicable.
  • Apply deer deterrent as necessary.