Ultimate Guide to Shrubs: Types and Classifications Explained

Shrubs are the backbone of the garden, offering structure and interest all year round. Whether they’re flowering, evergreen, or deciduous, these versatile plants can add depth, texture, and color to your landscape. They can be classified in a number of different ways. Some common groupings are by size (dwarf, medium, or large), growth habit (upright, spreading, or mounded), or main feature (flowering, foliage, or fruit). In this guide, I’ll run through the primary types and classifications to help you pinpoint the best types of shrubs for your own garden project.

What Are Shrubs?

Shrubs are woody plants that are between flowers and trees in size. Unlike trees with a single trunk, they usually have multiple stems growing from the ground.

These versatile plants come in many shapes and sizes. Some stay small, like rose bushes, while others grow into tall hedges. You’ll find both deciduous shrubs that lose their leaves and evergreen varieties that stay green year-round.

They also play important roles in gardens and nature:

• Prevent soil erosion
• Provide food and shelter for wildlife
• Offer privacy and windbreaks
• Add beauty with flowers and foliage

Gardeners love using shrubs as foundation plantings near houses. They also work well in borders, as focal points, or grouped together in beds.

Growth Habit Classifications

Shrubs come in various growth habits that affect their appearance and care needs.

Deciduous Shrubs

Deciduous shrubs lose their leaves in fall and regrow them in spring, bringing seasonal changes to the garden. Forsythia, with its bright yellow flowers, is a popular choice. It bursts into bloom before its leaves appear, signaling the start of spring.

Hydrangeas are another popular deciduous shrub. They offer big, showy flowers in summer, and their colors can change based on soil pH. Lilacs are prized for their fragrant spring blooms and heart-shaped leaves.

Evergreen Shrubs

Evergreen shrubs keep their leaves year-round. They add constant color and structure to gardens, even in winter. Boxwood is a classic option used for hedges and topiary. It’s easy to shape and stays green all year.

Rhododendrons and azaleas are flowering evergreens that bloom in spring. Yews are versatile evergreens that can be shaped into various forms. They’re often used for privacy screens or as backdrop plants.

Semi-evergreen Shrubs

These fall between deciduous and evergreen types. They may keep some leaves in mild winters but drop them in harsh conditions.

Abelia is a semi-evergreen with small, glossy leaves and delicate flowers. It blooms from summer into fall and attracts butterflies.

Nandina, or heavenly bamboo, is another semi-evergreen option. It has lacy foliage that turns red in fall and winter. Cherry laurel is a tough semi-evergreen that works well as a hedge or screen.

Size Classifications

Shrubs come in various sizes to fit different garden spaces and needs. From tiny dwarf varieties to towering large shrubs, there’s a perfect fit for every landscape.

Dwarf Shrubs

Dwarf shrubs are the pint-sized powerhouses of the garden world. These little guys typically grow less than 3 feet tall and wide. They’re perfect for small spaces, rock gardens, or as border plants.

Some popular options include:

• Dwarf boxwood
• Compact rhododendrons
• Miniature roses

These are great for containers too. You can move them around to change up your garden look.

Medium-sized Shrubs

Medium-sized shrubs usually grow between 3 to 6 feet tall and wide.

They’re versatile players in the garden, working well as:

• Foundation plantings
• Privacy screens
• Focal points

Some of my favorites include:

• Hydrangeas
• Azaleas
• Butterfly bushes

These offer a nice balance of impact and manageability. They can create structure in your garden without overwhelming smaller plants.

Large Shrubs

These giants can grow over 6 feet tall and wide. They make a bold statement and can really transform a space.

Some uses for large shrubs include:

• Creating privacy
• Defining property lines
• Serving as windbreaks

Popular options include:

• Lilacs
• Camellias
• Forsythia

These shrubs need more room to spread out. But they reward you with lots of flowers, foliage, and sometimes even fruit.

Growth Form Classifications

Shrubs come in various shapes and sizes, each with unique characteristics. These different growth forms affect how they fit into landscapes and gardens.

Compact Shrubs

These are small and dense, perfect for tight spaces. They typically grow 2-4 feet tall and wide and keep a neat, rounded shape without much pruning.

Popular varieties include dwarf boxwood and small hydrangeas. They work well as foundation plants or in rock gardens and make great borders and low hedges.

Spreading Shrubs

These grow outward more than upward. They can cover large areas, making them helpful ground covers. They often reach 3-6 feet wide but stay under 3 feet tall.

Juniper and cotoneaster are common varieties. They help control erosion on slopes and work well under trees or along fences.

Climbing Shrubs

These can grow vertically with support and use various climbing methods, like twining stems or clinging roots. They can reach heights of 20 feet or more.

Many types of climbing roses and clematis are popular choices. They add vertical interest to gardens covering walls, fences, or trellises.

Leaf Type Classifications

Shrubs have different leaf types that help identify them. The two main categories are broadleaf and needle-leaf shrubs.

Broadleaf Shrubs

These plants have wide, flat leaves that come in many shapes and sizes. Some are round, while others are oval or heart-shaped. The edges can be smooth, wavy, or have tiny teeth.

They often change colors in the fall. Some drop their leaves in winter, while others keep them all year.

Leaf arrangement matters, too. Some have leaves that grow opposite each other on the stem, and others have leaves that alternate sides as they grow up the branch.

Popular varieties include:

• Hydrangeas
• Azaleas
• Boxwoods
• Lilacs

Needle-leaf Shrubs

Needle-leaf shrubs have thin, pointy leaves. These leaves are usually evergreen, staying on the plant all year. They’re often clustered in groups or grow along the stem.

Some common varieties are:

• Junipers
• Yews
• Pines
• Spruces

They make great privacy screens. They also add year-round color to gardens.

Flowering And Non-flowering Classifications

Shrubs are divided into two main types based on their ability to produce flowers. Some bloom with colorful blossoms, while others focus on foliage.

Flowering Shrubs

Flowering shrubs add pops of color to gardens. These plants produce showy blooms in various shapes and hues.

Hydrangeas are popular for their big, round flower clusters that change color based on soil pH.

Roses offer classic beauty with their fragrant petals. Lilacs fill the air with sweet scents in spring. For year-round interest, try camellias. They flower in fall and winter when other plants are dormant.

Some also attract helpful wildlife. Butterfly bushes, as the name suggests, bring butterflies to your yard. Azaleas provide nectar for hummingbirds and bees.

Non-flowering Shrubs

Non-flowering shrubs shine with their leaves instead of blooms. These plants offer texture and structure to landscapes.

Boxwoods are prized for their dense, evergreen foliage. They’re perfect for hedges and topiary.

Yews are another evergreen option. They’re tough plants that tolerate shade and pruning well.

For a splash of color without flowers, try barberry. Its leaves are red, purple, and gold.

Some also have interesting bark or berries. Red-twig dogwoods have bright stems that stand out in winter.

Climate Tolerance Classifications

Shrubs have different tolerances for weather conditions. Some thrive in cold areas, while others prefer heat. Light preferences also vary among shrub types.

Cold-hardy Shrubs

These plants can handle freezing temperatures and snow. These tough plants often keep their leaves year-round.

Popular options like junipers and boxwoods stay green even in winter. Some, such as forsythia, also do well in cold climates. In early spring, it showcases lovely yellow foliage.

Rhododendrons and azaleas add color to shady spots in cool areas. Many berry-producing shrubs, like hollies and barberries, can also withstand the cold.

Heat-tolerant Shrubs

Hot climates need shrubs that can take the heat. These plants often have features that help them save water.

Thick or waxy leaves slow down water loss. Some drop leaves in very hot weather to conserve moisture.

Lantana is a colorful choice that loves the heat. It blooms all summer long with little care.

Oleander is another heat-lover with pretty flowers. But be careful – it’s poisonous if eaten.

For dry heat, try desert plants like yucca or agave. They store water in thick leaves or stems.

Crape myrtle is a good choice in humid heat. Its showy flowers and peeling bark add extra interest.

Shade-tolerant Shrubs

Shade-tolerant shrubs grow well with less sunlight. They’re perfect for spots under trees or on the north side of buildings. Many have big leaves to catch what light they can get.

Hydrangeas are popular shade options with big flower clusters. For year-round interest, try shade-loving evergreens. Yews and hollies keep their leaves and add structure to shady spots.

Some even bloom in the shade. Camellias have glossy leaves and pretty flowers. They do well in partial shade in milder climates.

For colder areas, try flowering quince. It has bright blooms in early spring.

Sun-loving Shrubs

Sun-loving varieties need at least 6 hours of direct sunlight daily. They often have smaller leaves to prevent water loss.

Roses are classic sun-loving shrubs, available in countless colors and styles. Lavender is another sunny favorite, with fragrant flowers and silvery leaves.

Butterfly bush is a sun-lover that lives up to its name. Its long flower spikes draw butterflies all summer.

Water Requirement Classifications

Shrubs have different water needs depending on their species and natural habitats. Some thrive in moist conditions, while others can handle dry spells.

Moisture-loving Shrubs

Moisture-loving plants need regular watering to stay healthy. These plants often come from areas with high rainfall or grow near water sources in nature.

Examples include hydrangeas, azaleas, and rhododendrons. They do best in spots that stay damp but not waterlogged.

Drought-tolerant Shrubs

Once established, drought-tolerant shrubs can handle periods of dry weather. These tough plants often have features that help them save water, like small leaves or waxy coatings.

Lavender, rosemary, and juniper are good examples. They need less frequent watering than their moisture-loving cousins.

Landscaping Classifications

Shrubs play key roles in landscaping, serving different purposes based on their placement and characteristics.

Hedge Shrubs

Hedge shrubs create living walls and borders in landscapes. These plants grow densely and can be trimmed into neat shapes.

Popular choices include boxwood, privet, and yew.

Border Shrubs

Border shrubs soften edges and fill spaces in garden beds. They come in many sizes, shapes, and colors.

Good picks include hydrangeas, spirea, and barberry.

Specimen Shrubs

These stand out as focal points in the garden. They often have striking features like unusual shapes, showy flowers, or dramatic foliage.

Examples include Japanese maples, camellias, and certain types of rhododendrons.

Groundcover Shrubs

Groundcover shrubs spread low and wide, covering bare soil. They prevent weeds and erosion while adding greenery.

Good choices include creeping juniper, cotoneaster, and low-growing spireas.

How To Choose The Best Shrubs For Your Garden

Picking the right shrubs for your garden can be fun and rewarding.

Start by looking at your space. How much sun does it get? Is the soil dry or moist? Knowing these basics will help narrow down your options.

Think about what you want from your plants. Do you need privacy, colorful flowers, or year-round greenery? Make a list of your top priorities.

Consider the size of mature shrubs. A tiny plant now could grow huge later. Check the plant tags or ask at your local nursery about expected heights and widths.

Don’t forget about maintenance. Some need regular pruning, while others are low-fuss. Be honest about how much time you want to spend caring for your plants.

Mix it up! Combine different types for visual interest. Try pairing evergreens with flowering varieties. This gives you color and texture all year long.

Resources And Further Reading

There’s a lot to learn and love about shrubs. Here are some of my favorite books and resources:

Books:

• Rodale’s Ultimate Encyclopedia of Organic Gardening – A go-to for organic gardening enthusiasts, this book covers everything from vegetables to shrubs with up-to-date advice on earth-friendly gardening practices and pest control. It’s a must-have for any serious gardener.
• Dirr’s Hardy Trees and Shrubs: An Illustrated Encyclopedia – Michael Dirr is a renowned expert in woody plants, and this book offers comprehensive information on shrubs and trees. The detailed descriptions and growing tips make it an invaluable resource for both beginners and experienced gardeners.
• Wyman’s Gardening Encyclopedia – This classic covers 9,500 plant species, including a wealth of information on shrubs. It’s well-organized, scientifically thorough, and includes both expert knowledge and practical observations for your garden.
• The Well-Tended Perennial Garden by Tracy DiSabato-Aust – Known for its extensive coverage on pruning, deadheading, and care of perennials, this book also covers many shrub species. It’s a great guide for keeping your shrubs looking their best year after year.
• Encyclopedia of Plants & Flowers by the Royal Horticultural Society – An extensive plant catalog that includes detailed shrub profiles, helping you choose the right plant for your space based on climate, size, and bloom season.

Online Resources:

• The National Gardening Association – This site offers plant care guides, a comprehensive pest control library, and a wealth of information on growing shrubs in different regions of the U.S.
• A Way to Garden by Margaret Roach – Margaret Roach’s blog covers a wide range of gardening topics, with a particular focus on native plants, shrubs, and perennials. She provides both practical advice and musings on nature.
• Cornell University’s Gardening Resources – Offering a wealth of horticultural information, this resource includes extensive guides on shrub selection, planting, and care for various regions and climates.

Forums and Communities

Getting advice from fellow gardeners can be incredibly useful. Websites like GardenWeb and The National Gardening Association have forums where people share their experiences and tips for growing shrubs.

YouTube Channels

For visual learners, channels such as Garden Answer offer practical video tutorials. They cover everything from planting techniques to seasonal care tips for shrubs.

Wrapping Up

Shrubs are a great way to add beauty and structure to gardens. They come in many shapes, sizes, and types. Some have colorful flowers, while others offer lush foliage year-round. Choosing the right options will ultimately depend on your garden’s needs. Think about sun, soil, and space, and consider mixing different shrubs for visual interest. Whilst evergreens provide a green backdrop, flowering varieties bring pops of color, and deciduous shrubs change with the seasons. Remember, shrubs grow over time, so plan for their mature size when planting.

Happy gardening!