Watering & Fertilizing

Correct watering is the single most important factor in establishing your new plantings. During the first year after planting, check all plants weekly by inserting your finger into the soil to a depth of two to three inches. Water when the soil is no longer moist. Slow, deep watering is preferred.

  • A slow trickle of water from a garden hose for 20 - 40 minutes should be adequate for trees and larger shrubs. We recommend the use of a gator bag or equivalent slow watering product.
  • Water smaller shrubs at a slow trickle for 10 - 20 minutes.
  • For perennials, annuals, and groundcover, running a soaker hose for 5 minutes or hand watering the area should be adequate.
  • Excessive, frequent watering is as bad for plants as no water, so check your soil before watering. Allowing the soil to dry out between waterings forces the roots to go deep in search of moisture, which will make the plant more resilient.
  • Fertilizer - Always read the directions when using fertilizer!
  • Fertilizer - If using fertilizer we always recommend going organic, which is slower to release and better for plants and lawn. Higher dosages are not always better - lower fertilizer values are more balanced.
  • Fertilizer - If using mulch, you do not need to fertilize. We recommend SteerCo Soil Conditioner and Cedar Grove compost.

When to water:

  • The best time to water is early morning before the temperatures begin to rise. Watering in the morning allows water to soak deeply into the soil providing the plants with a good amount of water to face the heat of the day.
  • If watering cannot be done in the early morning, late afternoon is also an option. It is important to water early enough in the afternoon so the leaves have time to dry before nightfall.
  • Allowing the leaves to dry before nightfall reduces the development  of fungal diseases.

How often to water:

  • The frequency of watering varies due to several factors - how recently the plants have been installed, season of the year, plant type, soil conditions, sun, temperature, and drying winds.
  • Grass seed should not be allowed to completely dry out from the day it is installed until well rooted. New sod should be watered twice per day in summer, and once per day in spring and fall until rooted.
  • A good rain measuring 1” or more is equivalent to one watering.

Watering with irrigation:

  • Please remember to keep an eye on your new plants.  Although the irrigation system has been installed and is running, larger plants and especially trees will need supplemental watering in dry and hot weather.  This is because the irrigation system design is predicated on the root systems of the plants being more extensive than they are at planting. The plants are container grown and all their roots are, at planting, contained in an area the size of the container they were grown in.  Over the coming years, their root systems will grow wider and deeper, but in the next 3 years especially they will need additional water.  Stick a finger in the ground adjacent to the root ball and if the soil is not moist – water!  Over time allow the soil to dry out between watering and that will force the roots to go deeper for moisture, creating a more resilient plant.


Tips for Weed Control:

Let sleeping weeds be

  • All gardens contain weed seeds, but only weeds in the top inch or two of soil get enough light to trigger germination and growth. Digging brings hidden weed seeds to the surface, so assume weed seeds are there ready to erupt every time you open a patch of ground.
  • Dig only when you need to and immediately amend the disturbed spot with plants or mulch.
  • In lawns, minimize soil disturbance by using a sharp knife with a narrow blade to slice through the roots of dandelions and other lawn weeds to stop their feed source rather than digging them out. Keep in mind that weed seeds can remain dormant for years.


  • Mulch benefits plants by keeping the soil cool and moist and depriving weeds of light. We always recommend organic mulches, which you can find at your local nursery.
  • Some light passes through chunky mulches, and often you may find that the mulch you used was laced with weed seeds. Replenish the mulch as needed to keep it about 2 inches deep (more than 3 inches deep can deprive soil of oxygen).


  • Commit to a weeding schedule. This will keep maintenance manageable.
  • There is an old saying “Pull when wet; hoe when dry”, which we think is wise advice with weeding. After a rain storm, equip yourself with gloves, a sitting pad, and a tarp for collecting the corpses. An old fork will also help because there’s nothing better for twisting out tendrils of weeds. When going after bigger weeds, use a fishtail weeder to pry up taprooted weeds, like dandelion.
  • If weeding large areas, nothing beats a shuffle hoe. Make sure to keep the edges sharp.


  • When you can’t remove weeds, the next best thing is to chop off their heads. With annual weeds, dead­heading buys you a few weeks of time before the weed “seed rain” begins.
  • Use pruning loppers to take down tall weeds, or you can step up to a string trimmer equipped with a blade attachment to cut prickly thistles or brambles. No matter which method you choose, chopping down weeds before they go to seed will help keep them from spreading.

Mindful Watering

  • Water the plants you want, not the weeds! Put drought on your side by depriving weeds of water.
  • Placing drip irrigation beneath mulch efficiently irrigates plants while leaving nearby weeds thirsty. In most climates, depriving weeds of water reduces weed-seed germination by 50 to 70 percent.

Keep Soil Healthy

  • Enriching your soil with organic matter every chance you get can help your garden down the weed-free path.

Invasive Plants to Avoid:

  • Acer plantanoides, Norway Maple
  • Aesculus hippocastanum, Horse chestnut
  • Buddleja species, Butterfly bush
  • Calystegia sepium, Hedge false bindweed
  • Clematis vitalba, Wild clematis
  • Cotoneaster spp., Cotoneaster
  • Cytisus scoparius, Scotch broom
  • Daphmone laureola, Spurge laurel
  • Equisetum, Horsetail
  • Hedera helix, English ivy
  • Ilex aquifolium, English holly
  • Ipomoea purpurea, Morning glory
  • Lamium galeobdolon, Yellow archangel
  • Lythrum salicaria, Purple loosestrife
  • Lysimachia vulgaris, Garden loosestrife
  • Polygonum, Knotweed
  • Prunus laurocerasus, Cherry laurel
  • Pyrus calleryana 'Bradford', Bradford pear
  • Rubus discolor, Himalayan blackberry*
  • Rubus laciniatus, Evergreen blackberry*
  • Sorbus aucuparia, European mountain ash
  • Taraxacum, Dandelion

Links for a full list of King County Noxious Weeds:

  • http://www.kingcounty.gov/environment
  • http://www.kingcounty.gov/environment/animalsAndPlants/noxious-weeds/laws/list.aspx

* If you have a steep slope with blackberry shrubs, do not tear them out! Blackberry shrubs have deep and strong root systems that do an excellent job of retaining slopes.

Irrigation System

Similar to any other product installed in your home, an automatic sprinkler system needs to be properly maintained. Maintaining your sprinkler system will conserve water and save money, and regularly scheduled maintenance will ensure that your irrigation system operates efficiently throughout the year.

Spring Maintenance:

  • Each spring, your irrigation system should be turned on: its control panel should be plugged in and adjusted, water should be slowly turned on, and each zone of the system should be run on a short cycle to allow for a visual inspection.
  • Broken, clogged, and misaligned parts; broken pipes; and inadequate water pressure are common problems caused by normal wear and tear that can be addressed at this time.
  • Common irrigation maintenance issues to look out for:
  • Clogged sprinkler nozzles should be cleaned out.
  • Misaligned sprinkler heads should be repositioned and their spray should be adjusted for proper coverage.
  • Broken sprinkler heads and pipes can be repaired or replaced by a knowledgeable homeowner or professional contractor.
  • Water pressure issues should be handled by a professional contractor. Low water pressure will not adequately water your lawn, while high water pressure can cause damage to sprinkler heads, or ‘misting’ which results in inefficient watering.
  • Backflow prevention assemblies are installed inline after the main water control valve. The assembly is important to your health and safety, preventing water used to irrigate your lawn from returning to the indoor water lines and contaminating your home's water supply. Most cities and municipalities will test or require a yearly test of the backflow prevention assembly by a certified professional tester. You should contact your local authorities to determine the requirements for your area.

Summer Maintenance:

  • It’s good practice to check your irrigation system during the daytime on a monthly basis to make sure your system is working properly. Any necessary repairs or adjustments should be made as soon as possible.
  • During the summer months, areas of your landscape may require more or less water depending on heat and rainfall. Making the proper adjustments as needed will ensure that water is not wasted by overwatering.

Winter Maintenance:

  • As the cooler weather of fall creeps in, keep up with your monthly maintenance checks.
  • In Fall, you should winterize your sprinkler system before the first freeze. Winterizing an automatic sprinkler system is accomplished by blowing all of the water out of the system with an air compressor. Although some systems have drains, it is still good practice to blow them out, as any residual water has the potential to freeze, expand, and crack the system's pipes and fittings. We recommend having a professional irrigation contractor blow out your system.

Lawn Care

The natural cycle of cold weather grasses in the PNW is to go dormant in summer. A green lawn is a social and cultural phenomenon, not a natural one, maintained through forcing growth with water and nitrogen.


  • Mow frequently
  • Do not mow more than1 ⁄ 3 of the blade, and no shorter than 2″


  • There are two schools of thought regarding summer lawn care… here are both, you decide!
  • Let your lawn go brown. Water once a month to keep the roots alive. Lawn can be dormant for three months without damage. This will save greatly on water, but some weed invasion will occur.
  • Keep watering to keep your lawn green. Lawn is still dormant so use very little or no fertilizer. If you do use fertilizer, make sure to use slow release.


  • Lawn starts growing again with cooler weather and increased rains. Fall is a good time for intensive lawn management. Mow as needed and aerate annually each fall. Overseed to develop a thick sward before winter when the grass goes dormant again and the moss invasion commences.
  • Lime - If fertilization does not seem to work your soil could be too acidic - add lime to balance the soil pH. This can be done every 2 - 3 years.


  • Winter is time to leave your lawn alone. Do not mow and do not fertilize.

Care for New Sod Lawns

Your new lawn has been carefully installed, and needs proper continuing maintenance, particularly in the next several weeks, to ensure the success of the installation. Please follow the watering and care instructions below for the next several weeks.


  • You may walk on the lawn to move sprinklers, but keep non-essential foot traffic to an absolute minimum during the initial establishment period.
  • If the edges between the sod pull apart or are separating, you are not applying enough water. The sod is shrinking and pulling apart.
  • Do not water at night or late in the evenings. New seedlings are susceptible to diseases, which are encouraged by prolonged periods of being wet.
  • Make sure to water along pavement surfaces when the temperatures are warmer, as the sod will literally bake next to the hot surface during the establishment.

Maintenance Practices (0-10 days):

  • Water each day for at least 15 to 20 minutes in each area of lawn (according to how much water your sprinkler emits).  Watering a second time each day is recommended if the temperatures are over 65º and sunny. It is important to get the water through the sod and into the soil below the sod. Check to make sure you are watering enough by pulling back the corner of the sod in several places throughout the lawn to make sure the soil below is moist.  Do not fertilize or mow the lawn yet.

Maintenance Practices (10 to 21 days):

  • Water every other day for approximately 30 minutes. By watering for longer periods of time, you are encouraging root growth deeper into the soil.  Check to make sure you are watering enough by pulling back the corner of the sod in several places throughout the lawn to make sure the soil is moist – not wet. The sod should be difficult to pull up – do not force it up. The root system is establishing... and should not be pulled from the soil. Just tug lightly to assure good rooting.  If the lawn is not rooting, you may not be watering enough.
  • Once rooted, cut the grass as needed. Do not remove more than a third of the grass plant at one time while cutting. For instance, if the grass is 5” tall, do not cut below 3.5” in height. In general, keep the lawn at 2.75” to 3.5” during the establishment. If the lawn is too wet to cut, do not water for one more day and then cut the lawn.  Do not apply fertilizer to the lawn yet.

Maintenance Practices (3 weeks and beyond):

  • You may begin to cut the lawn as needed. The lawn should be fairly well rooted and can take normal wear and tear.  Water the lawn approximately twice a week making sure to apply 1” of water each week. Use a pie tin or similar container to measure your irrigation by placing it in the path of the sprinkler. Multiply the amount of water in inches by the number of times you water each week to total 1” per week. For instance, 1/2” for two waterings equals 1” of total water.
  • You may apply a balanced organic turf fertilizer six weeks after installation. Either your lawn care company will apply your fertilizer or you may use a consumer product,. If you are applying the product, follow the label instructions very carefully. It is recommended that you use a rotary spreader as opposed to a drop spreader.
  • Look for a fertilizer that has a nutrient ratio of 3:1:2, which indicates the amount of nitrogen, phosphorus and potassium (NPK).  Apply fertilizer at half the normal rate in shady lawn areas.  Make spot weed control applications as needed, no sooner than 10 weeks from installation date.  If you decide to use pesticides, use them sparingly and only as needed.

Ongoing Lawn Maintenance

Mowing is one of the three primary cultural practices that are used to sustain turfgrass growth. Mowing that is consistent and frequent can help develop a turf grass stand that is dense, of fine texture, more resistant to insects and diseases and becomes more drought tolerant due to the establishment of deeper root zones. Some frequent questions include:

How high should I mow my turf?

  • The actual height of the turf is dependant on the turf species. Northwest lawn mixes are a mix of three species that performs best when maintained at a height ranging from 1 ½ inches to 2 ½ inches. If you maintain your lawn at heights above this range the turf may present a more ragged, natural look. These heights are usually in areas that require less maintenance requirements and aesthetic demands are minimal. At  the lower part of the range and below, our grass respond with increased density, finer texture and improved playability. However, lower cutting heights also produce some potential negative side effects. These include crown tissue damage (scalping), increase potential for diseases, reduced carbohydrate reserves, less root mass, increased temperatures at the soil/plant interface and the reduction of photosynthetic area.

How often should I mow my turf?

  • Some say that once per week is how often a lawn should be mowed. However, the determination of when the grass should be cut must be based on grass growth and the underlying functions of grass growth. These include time of year, grass species, intensity of use and maintenance practices. A good rule of thumb is the '1/3 rule'. This rule states that no more than one-third of the grasses top growth should be removed at any one mowing. This rule provides a balance between the benefits of frequent mowing (increased density, regrowth) and the negative consequences of too frequent mowing (decreased shoot and root growth, depleted carbohydrate reserves, and a weakened, stress intolerant plant).

Should I collect my grass clippings?

  • Whether you remove the clippings or not depends on a few, specific factors. First, if the turf stand is intensively maintained with closely mown surfaces, such as for sports fields, the clippings should be removed to maintain appearance and playability. Second, so long as the turf is mowed in a regular and consistent manner in which the amount of top growth is minimal, the clippings may be left. If, however, the clippings are larger than normal due to infrequent mowing the clippings should be removed. Regardless, the fertility program should be altered to account for either the increase of nutrients (leaving the clippings) or the absence of nutrients from the organic material.

What type of mower should I use?

  • The best mower you can use is a sharp mower. The differences between a rotary mower and a reel mower are technical and are only apparent in intensely maintained turf grass applications. For the majority of uses, the type is not as relevant as the sharpness. A dull mower will damage the ends of the leaves causing brown, ragged ends and allow for increased disease development.


Once a lawn is established it will require about one inch of water per week between May and October. During the hottest weeks of summer the lawn may require 1 ½ " – 2" of water per week. Encourage deeper root growth by watering less often, but deeply. A lawn that sheds water quickly will need to be watered in several shorter cycles. Lawn areas are commonly over watered and improving water distribution and application timing can usually save significant amounts of water. The best time to water is early morning to reduce vaporization and evaporation. As a rule of thumb, watering during periods when "dew" would be expected to appear naturally will minimize fungal infections (Red Thread, Rust) caused by water standing on the leaf surface for long periods of time. If you use an automatic irrigation system be sure to adjust the timer throughout the year. In running your system, make sure you have programmed the proper duration and frequency of your watering cycles (as necessary for your soil type, slopes, plantings, and exposure to sun and shade). Watering needs in your landscape will change as weather patterns change during the season, and from year to year as your plantings mature or are modified.

Signs of inadequate watering:

  • Blue/gray tint
  • Brown spots
  • When walked on, footprint stays for more than 30 seconds.

Planted Yard: Perennials & Grasses

Perennial Plants

A perennial is a plant that lives for more than 2 years. Most perennials bloom over the spring and summer, die back every fall and winter, and then return in the spring from their root-stock.

  • Watering Perennials - There's no one-size fits all rule for watering perennials. Some varieties stand up to drought and others need to be kept moist all the time. The important thing to remember is to be sure to keep them well watered the first year. That allows them to become well established.
  • Fertilizing Perennials - If you have rich soil or amend it with compost or other forms of organic matter on a regular basis, you probably won't need to fertilize your perennials. But if your perennials seem to be struggling it may be worth testing your soil. Local nurseries have soil test kits that can help determine the acidity of your soil. If you decide you need to fertilize they can also help you decide on a product that matches your soils needs.
  • Deadheading Perennials - Deadheading simply means cutting the faded flowers off your plants. It makes your plants look better and it prevents them from setting seed. Many perennials respond to deadheading by putting out more blooms!
  • Dividing Perennials - One of the best things about perennials is that they grow bigger and better each year. But many will start to crowd themselves out if they get too big. Keep them performing well by digging them out of the ground and splitting them into smaller chunks every three or four years. Early spring and fall are the best times to do this as the weather is cool.
  • Winter Care for Perennials - Perennials that are reliably cold hardy in our region shouldn't need any special winter care, but spreading a layer of mulch over them after the soil freezes can help prevent winter damage during an especially cold season.

Ornamental Grasses

There are many varieties of ornamental grasses that thrive in our region. Grasses are generally classified as cool season or warm season. Cool-season grasses put on most of their growth in spring before temperatures begin to reach 75 degrees Fahrenheit, and in the fall when temperatures cool down. They generally maintain good color through the summer but won't grow much when it is hot. Warm-season grasses start growing mid to late spring or even early summer. Their major growth and flowering happens when the weather is hot. They will usually turn shades of brown for the winter.

Cutting Back Ornamental Grasses

There are two options when considering cutting back ornamental grasses, 1) cut them back prior to new growth or 2) don’t cut them back but be prepared to sift out the dead blades in spring to allow for the new growth to emerge. If you decide to cut back here are our tips:

  • Cutting back warm season grasses - Once your warm season grasses turn brown you can trim them back at almost any time. If you like to tidy your garden in fall trim warm season grasses so they are just a few inches tall. You can also leave the dried grasses and seed heads in your garden for winter interest. If you leave the trimming until spring try to make sure to cut them back to the ground (you can leave a couple of inches) by late spring, before new growth begins. Not all ornamental grasses look good through the winter, trim back those that don't look good in the fall.
  • Cutting back cool season grasses - Cool season grasses tend to look good even as the weather cools, so you can leave their foliage in place until early spring. Leave about 1/3 of the plant in place when cutting back.

Planted Yard: Trees & Shrubs (Planting, Transplanting and Pruning)

Planting and Transplanting Trees and Shrubs

When thinking about planting and transplanting trees and/or shrubs the most important thing to remember is ‘right plant, right place.’ By this we mean that it is crucial to consider a plants light, water and drainage needs when deciding where to plant it in your garden. Plants will have information regarding their needs, all you need to do is follow them! If you do this correctly you shouldn’t have much maintenance to worry about.


  • It is best to plant and transplant new trees and shrubs in the fall (after they have gone dormant, late October or early November) or early spring (before new growth appears, around late March).


  • When planting and transplanting watering is important. Newly planted plants require routine watering. Typically, 5-7 gallons, applied to the root ball once a week, is an appropriate quantity of water to add to a newly planted tree or shrub. If the soil feels dry or just slightly damp, watering is needed. Soil type and drainage must also be considered. Well-drained, sandy soil will need more water, and more often than a clay soil that may hold too much water. A slow trickle of the garden hose at the base of the plant until the soil is thoroughly soaked is a good method. Short, frequent watering should be avoided as this does not promote deep root growth.


  • Adding a mulch around the base of the plant is a very important part to planting and transplanting. By mulching plants, a more favorable environment is provided for the tree roots. Apply a 3 inch layer of mulch, spread to form a 3-6 foot diameter circle around the plant, and keep the mulch material away from direct contact with the plants trunk(s).

Pruning Trees and Shrubs

  • Trees and shrubs generally do not need to be pruned immediately before or after planting as most nurseries prune prior to sale.

Pruning Trees

  • Avoid pruning a young or newly planted tree - it needs as many leaves as possible to produce good root growth. Remove only dead, broken, or injured branches, as well as those that cross or rub each other. Prune back to a healthy stem or branch, which eliminates hiding places for pests and diseases, and looks better. Do not cut back the plant's leader — the top-most growing point of the tree — which is vital to letting the tree develop its natural form.
  • Once the tree is a few years old, you can shape it by gradually pruning over the course of several years to maximize foliage and flowering. The tree's branches should be well-spaced up the trunk and spiraling around it. As a guideline, prune no more than one-fourth of the tree's total leaf area in a single year. To raise the tree's crown or create clearance beneath it, remove the lowest branches. Also target branches that are spaced too closely together or that join the trunk at a narrow angle. These form weak limb attachments and will break easily in wind or under the weight of snow.
  • Mature trees require only occasional pruning to maintain their structure and appearance. Never cut off the top of a tree's canopy to reduce its size. Topping typically leaves the tree much less attractive and much more prone to weak growth and pests.

Pruning (Flowering) Shrubs

  • Young shrubs can be pruned lightly to make them grow fuller. With hand pruners, trim long, unbranched stems by cutting just above a healthy bud. This type of pruning is called heading, and it encourages lower side branches to develop and enhances the shrub's natural form. When selecting a bud tip to trim to, keep in mind that the new branch will grow out in the direction of the bud. Like most pruning, pruning should be timed to avoid disrupting the plant's flowering.
  • As shrubs grow, thin out old, weak, rubbing, or wayward branches where they merge with another branch. This opens up the middle of the plant to more sunlight, which keeps interior branches healthy, stimulates growth, and increases flowering.