Gardening 101

Gardening can be extremely rewarding and enjoyable. Plants can improve the look of your home and help create outdoor spaces where you’ll want to spend time. You don’t need years of experience to become a good gardener, but there are some important basics that will help you pick plants and site them where they will thrive. 


Some gardening terms helpful when selecting plants for your garden:

Deciduous, herbaceous, & evergreen: These terms refer to what a plant does in winter. Evergreen plants hold on to their leaves in winter. Deciduous plants drop their leaves in winter. Herbaceous plants are soft-stemmed – they die to the ground in winter and come back the following spring.
Annuals, biennials, & perennials: Non-woody plants are grouped according to how long they live – annuals complete their whole life cycle in one year, biennials live two years, and perennials live three years or more. Most perennials are herbaceous, but some are evergreen. Grasses are included in these groups.
Trees, shrubs, and vines: Trees and shrubs are plants that form wood. Vines can be either herbaceous or woody. Think of vines as trees or shrubs without stiff, straight trunks and remember many can grow to huge proportions.
Zones: The USDA developed hardiness zones for different geographic areas based on average lowest winter temperatures. For example, most of western Washington is USDA zone 8, meaning plants labeled zone 8 or lower (7, 6, etc.) will generally survive our winters. 


The intensity of sun changes thru the day as it moves across the sky. During the growing seasons (spring and summer), morning/late afternoon light is much less intense than between 10:00 am- 6:00 pm. Plants cannot all tolerate the same duration or intensity of light, so it is crucial to know how much sun an area gets in summer to pick plants correctly.

Full sun: A plant prefers 8 or more hours each day of direct sunlight. These conditions are generally found out in the open on the south and west sides of buildings, trees, fences, etc.
Part sun and part shade: Prefer 4-8 hours of direct sunlight per day. Plants preferring these conditions usually like to be shaded from the intense afternoon sun. Part sun/shade is usually found on the east sides of buildings and large objects.
Shade: Means 4 hours or less of direct sunlight per day usually found north of buildings or large objects, and under trees and shrubs.


All soil is made up of three things: Inorganic matter (tiny pieces of broken down rock), organic matter (decayed remains of leaves, sticks, organisms, etc), and pore spaces filled with air and water.

Inorganic matter: It takes between 500 and 2,000 years to make one inch of soil through the weathering of rocks. Soil scientists group these inorganic particles based on their size: large particles (2mm - .05mm) are called sand, small particles (.05mm - .002mm) are called silt, and very small particles (.002mm and below) are called clay. The proportion of each determines the type of soil.
The ideal soil for plants is called "loam." Its composition is: 50% pore space filled with 25% water/25% air, 45% inorganic matter, 5% organic matter.
The importance of pore space: If there isn’t enough pore space in soil, water and air can't get to the roots of plants, or to the microorganisms living in the soil. The amount of pore space depends largely on the type of soil (sand, loam, or clay), and whether or not the soil has been compacted.


To improve soil, add compost: Compost is a mix of organic materials that are partially decomposed. Adding compost to clay soil improves drainage by breaking up the tightly packed clay particles. When added to sandy soil, it increases the ability of the soil to hold water by acting like little bits of sponge. Compost returns nutrients that are removed by hungry plants, provides habitat for the microorganisms that live in soil, and attracts organisms (like earthworms) that loosen the soil and increase pore space. Adding compost into soil or layering it on top of soil mimics how organic matter is recycled back into the soil in nature.
How to add compost: When preparing a new bed, till compost into the entire area to a depth of one foot. For existing planting beds, particularly those with annuals and perennials, use compost as a mulch (see below). Rain and earthworms will move the compost down into the soil.
To protect soil, use mulch. Mulch is a generic term that refers to any protective covering put on the surface of soil. Mulch can be organic (compost, leaves, bark, cardboard, etc.) or inorganic (plastic, weed barrier, etc.) and is extremely beneficial because it helps retain moisture, control weeds, moderate temperatures, and prevent erosion.
Which mulch should I use? Organic mulches are better for the soil, plants, and planet. Annuals and perennials - lay about 3 inches of compost or other fine-textured organic mix on top. Shrubs and trees - lay about 3 inches of bark mulch or wood chips on top of the soil.
Note: Leave the area around the base of each plant free of mulch. When mulch gets piled up around the stem or trunk of a plant it can lead to rot, killing the plant.


The basics: Two approaches are used. You can go to a store to find plants for a specific area, or you can find plants and then try to figure out where to put them. Most of us try to do the former but end up doing the latter. That is part of the fun. With either method, there are three main things to think about when picking out a plant: how much light it will need, how much water it will need once established, and how large will it get.
Select plant based on mature size: Avoid plants that will outgrow the amount of space you have. Many shrubs and trees can be pruned to stay smaller, but as they age, the more you prune, the more misshapen they look.
Picking out a plant: Look for plants that appear healthy and have lots of new growth. When removed from the container, they should have a thorough netting of visible roots but not a tight, hard, solid mass of roots (a.k.a. root bound). When shopping for trees, try to look for specimens with evenly spaced branches that are not broken, misshapen, or heading in strange directions.


Proper planting techniques make a big difference in the long-term health of plants, particularly in shrubs/trees. Remove the plant from the container and break up the root ball with your hands or a sharp tool to encourage the roots to grow out into the soil, rather than around and around.

Dig a planting hole as deep as the container and two to three times as wide.

Place plant into the hole, making sure the surface of the soil is even/slightly above level of the surrounding soil.

Important! – do not bury the root flare: For most plants, it is very important that none of the stem or trunk is below the soil level. If it is, or if soil or mulch piles up around it, the stem or trunk can rot and the plant can die. For shrubs and trees, it will often not kill the plant immediately, but rather will lead to problems in the future and shorten its life significantly. If in doubt, planting a bit too high is better than planting too low.

Refill the hole with the original, native soil. Press gently on the soil to remove air pockets and water thoroughly. If desired, fertilize with an organic, low number, balanced organic fertilizer .

Mulch with moist compost or bark.


Water is essential to the survival of plants. Without it, they will die. Proper watering techniques are necessary to create healthy, long-lived plants. Water deeply and less frequently. Frequent watering with small amounts of water creates shallow-rooted, thirsty plants. To encourage the plant roots to grow down into the soil, it’s important to water deeply, to the base of the roots. Using this method of watering, in addition to organic mulch, you’ll find that you need to water much less frequently, as your plants become naturally more drought tolerant due to deeper roots and healthier soil.

How often to water: Most plants need to be watered when the soil below the plant has dried out (just push your finger in a few inches). That said, here are some guidelines:
Annuals: Most annuals require regular watering throughout their life to support their fast growth and profuse blooming.
Perennials: Perennials generally need to be watered regularly until they are established, which takes about a year. After that, their needs vary based on the plant – some plants, like lavender, will need no additional irrigation while others will continue to need regular watering during the dry months.
Trees, shrubs, and vines: Woody plants generally need to be watered regularly until they are established, which takes one to three years. After that, their needs vary based on the plant.
Check your watering skills: To see if you have watered deeply enough, after you water you can dig a hole in the bed. If the water hasn’t penetrated to about 12”, or to 18” for large shrubs and trees, keep watering. Make a note of how long this took. The next time the soil dries out you’ll know how long you need to water.
Water the soil, not the leaves: Plants absorb water through their roots, not their leaves. Therefore, the goal is to water the soil, not the part of the plant that you can see. Overhead watering creates moist air and wet leaves, attracting insects and encouraging disease.


Early spring: Late February through March is a great time to clean up the garden for spring. Dead foliage can be cut off a few inches above ground, and leaves and debris can be raked and composted (or left to decompose naturally). Spring and fall are ideal times to plant, transplant, and divide as needed. Seeds, summer blooming bulbs, and bare root shrubs and trees are readily available. An annual application of organic mulch should be added on top of the soil in fall or early spring to about 3”, and then replenished as needed throughout the year. In March, a light application of balanced, organic fertilizer can be applied, if desired.
Spring: Spring rains will result in lots of lush new growth. Mulch will help keep down weeds, but some weeding will likely be necessary. Keep planting and transplanting as needed. Even though it’s raining, keep an eye on new plants since they can dry out quickly.
Summer: May through September is the time when your “water deeply and less frequently” skills are needed. Replenish mulch where it has gotten thin. Although not ideal, you can continue to plant in early summer if it can’t wait until fall, but you’ll need to pay close attention to watering. Deadheading (removing spent blooms) is not necessary, but will encourage additional blooms on many flowering plants.
Fall: Fall is a great time to start planting, transplanting, and dividing again. Spring blooming bulbs are available and ready to plant. Fall clean up begins as herbaceous plants start dying down and deciduous plants lose their leaves. If not added in spring, an annual application of organic mulch should be added on top of the soil at this time to about 3”. Small leaves can be left in planting beds to decompose. Large leaves can be removed and composted.
Winter: Planting woody plants and groundcovers throughout winter is okay, just avoid planting when soil is soggy and squishy, or when the ground is frozen. Don’t forget to water new plantings if it is not raining significantly. Perennials can be planted but be aware that you may lose some plants if we have a hard winter.