Food Forest Perennials List: Essential Plants for Abundant Yields

If you want your garden to work for you year after year, a food forest packed with diverse perennials can give you fresh fruits, nuts, vegetables, and herbs with less replanting and maintenance. Unlike annuals, perennial plants keep coming back without starting from seed every season, saving you both time and effort. Planting a mix of edible perennials fills out every layer in your food forest, from tall fruit trees and nut trees to small berries, leafy greens, and even ground-cover crops.

Adding more perennial crops isn’t just practical—it builds a healthier ecosystem in your yard. The right mix supports the soil, encourages pollinators, and helps your space adapt better to weather changes. If you’re ready to start or expand your own backyard food forest, a well-chosen list of perennials matched to your climate and needs is the best place to start.

Key Takeaways

• Choose perennials for a productive, low-maintenance food forest.
• Use a layered approach to maximize space and yield in your garden.
• Match perennial selections to your climate for better success.

What Is a Food Forest and Why Grow Perennials?

A food forest is a carefully planned garden that copies how natural forests grow by layering different types of edible and useful plants. Growing perennials in a food forest helps you get more food with less work while also supporting the soil, water, and wildlife on your land.

Benefits of Edible Perennials

Edible perennials, such as asparagus, rhubarb, and berry bushes, come back year after year with little effort on your part. You only need to plant them once, and they will produce food for many seasons. This saves time and cuts down on yearly planting.

Perennials often have deeper roots than annuals. These roots allow plants to gather water and nutrients from deeper in the soil. Because of this, they are more drought-resistant and can survive weather changes better than many annual vegetables.

Planting edible perennials also helps create a stable, low-maintenance food supply in your garden. These plants improve soil by dropping leaves and organic matter, which adds nutrients back into the ground. Perennials also offer steady habitats and food for insects, birds, and pollinators, which helps your whole garden ecosystem.

Differences Between Perennials and Annuals

The main difference between perennials and annuals is their life cycle. Perennials live three years or more, regrowing from their roots each spring without replanting. Common examples are raspberries, herbs like oregano, and trees like apple and pear.

Annuals, like tomatoes, beans, or lettuce, finish their life cycle in one growing season. They need to be replanted each year, which takes more time and effort.

With perennials, your food forest can keep producing with less work. You don’t have to dig, replant, or disturb the soil as often. This approach helps maintain soil structure and reduces erosion. A garden with a mix of both lets you enjoy reliable crops now and in the future. See more on starting a food forest with perennials.

Role of Perennial Plants in Ecosystem Health

Perennial plants play a key role in ecosystem health by helping your land stay fertile and resilient. Their thick roots hold soil in place, stopping erosion and protecting water quality. These plants pull up nutrients from deep in the ground, making them available for nearby plants.

As perennials shed leaves and parts of their stems, they build up organic matter that feeds the soil’s living organisms. This natural cycle leads to richer, healthier soil over time. A diverse food forest with many perennials also attracts pollinators and beneficial insects, supporting birds and other local wildlife.

By choosing a mix of different perennials—such as berry bushes, vines, understory herbs, and ground covers—you help mimic the natural patterns found in wild forests. This supports a productive, balanced food forest ecosystem that can handle pests, changing weather, and other challenges with less work.

Designing a Food Forest: The Seven Layers

Each layer of a food forest has a specific role, from tall trees that provide shade to low plants that build soil health and protect roots. Including a variety of perennials in the right places helps increase harvests, support pollinators, and keep your forest garden healthy.

Canopy Layer

The canopy is made up of the tallest trees in your food forest. You will usually find full-sized fruit trees and nut trees in this layer. Apple, pear, chestnut, walnut, and pecan are strong choices.

These large trees block wind, create shade, and provide a home for birds. Their leaves and fallen branches make great mulch for fruit trees and help the soil hold water. Sometimes, you can add nitrogen-fixing species like black locust or alder to enrich the soil.

Be careful not to overcrowd this layer. Choose trees that give enough space and sunlight to smaller plants below. Trees in the canopy often bloom early, giving pollinators a food source in spring.

Understory Layer

Directly underneath the canopy, you will find smaller fruit trees on dwarf or semi-dwarf rootstocks, such as peach, nectarine, and plum. These trees need less sunlight and fit well in the partial shade created by the tallest trees.

Nut trees like hazelnut can also work in this layer if the canopy is open enough. Dwarf varieties are especially helpful in limited spaces. Some people add trees such as medlar, pawpaw, or serviceberry for more variety.

Prune these understory trees to keep them open and make sure light reaches the forest floor. Select types that flower at different times to keep pollinators coming throughout the season. Mixing species reduces disease and attracts more helpful insects. Visit this guide on food forest layers for a detailed plant list.

Shrub Layer

The shrub layer fills the space between tree trunks. Bushes like currant, gooseberry, blueberry, and raspberry are common. Some people also add nitrogen-fixing shrubs, such as Siberian pea shrub or Elaeagnus.

Shrubs can provide berries and nuts, attract insects, and break up the wind for lower plants. Many shrubs flower at different times, feeding bees and other pollinators when trees are not blooming.

Add flowering woody plants like rose or butterfly bush for extra color and biodiversity. This layer can be dense but should not block sunlight from lower layers.

Example Shrubs Table:

Groundcover, Vine, and Root Layers

The groundcover layer covers bare soil to stop weeds. Low-growing plants like strawberries, clover, and creeping thyme are great for holding in moisture and building healthy soil. Many groundcovers attract pollinators too.

Vines use vertical space and can be grown alongside trees or shrubs. Grapes, kiwi, and hardy passionfruit will climb if you provide them with something to cling to. These plants increase the yield in smaller spaces.

The root or rhizome layer includes perennial root crops like Jerusalem artichoke, garlic, and daylily. These add food production below ground and loosen the soil for healthier trees and shrubs.

When picking plants for these layers, look for varieties that are not aggressive or invasive in your area. Rotate groundcovers and root crops to maintain soil fertility. Having many layers with a wide range of plants will provide year-round food and habitat. For an overview, see this description of the seven food forest layers.

Top Fruit Perennials for Food Forests

Fruit perennials are critical in any food forest. These plants give you reliable harvests, support wildlife, and can thrive in different climates and soils.

Apples and Pears

Apples and pears are classic and productive choices for food forests. Both trees offer a range of varieties suited for fresh eating, baking, or making preserves. Apples come in hundreds of cultivars, and you can select disease-resistant types for less maintenance.

Both trees prefer full sun and well-drained soil. Apples and pears typically need a second tree nearby for pollination and best fruit set. Dwarf and semi-dwarf rootstocks keep trees compact and easier to harvest.

Pears are more tolerant of less-than-ideal conditions than apples. Pruning once a year helps shape the canopy and maintain airflow, which reduces disease. These trees can live for decades, giving you fruit year after year. Their spring blossoms also attract lots of pollinators.

Mulberries and Jostaberry

Mulberries are fast-growing and well-suited for a low-maintenance food forest. Their trees handle a range of soils and climates—from temperate to subtropical. The fruits look like long, dark raspberries and are sweet with a hint of tartness.

Mulberry trees start producing in just a few years. Their berries are great for eating fresh or making jams and pies. They also attract many birds, so some netting may be helpful to protect your harvest.

Jostaberry is a cross between currants and gooseberries. The bushes are hardy and easy to grow. Jostaberries produce large, black berries that taste slightly sweet and tart. Their spreading habit makes them good for hedges or as understory plants. Jostaberries don’t have thorns and are resistant to common berry diseases.

Olives and Haskap

Olive trees are best for warm, dry climates and can live for centuries. They need full sun and well-drained poor soils. Olives produce fruit for oil, pickling, and eating. While they are cold-sensitive, some newer varieties can handle mild frosts.

They need pruning to control shape and airflow. Olives require a few years of growth before fruiting, but after that they give regular crops with little extra care. If you live somewhere with very cold winters, olives likely won’t survive outside.

Haskap is also called the honeyberry. These shrubs are well-suited for cold climates. The plants yield blueberry-like fruits in early summer. Haskap bushes tolerate a range of soils and are resistant to most pests and diseases. They are very hardy and can survive freezing winters, making them popular in northern areas. Plant at least two different varieties for best pollination.

Kiwi, Grapes, and Blueberries

Kiwi vines can produce a lot of fruit in a small space if you use a strong trellis. Hardy kiwi varieties grow in cooler climates and do not need as much heat as the fuzzy kiwi in supermarkets. Plant male and female vines for fruit set. Kiwis need regular watering and well-drained soil.

Grapes are productive and useful for eating fresh, juicing, or making raisins. Choose disease-resistant varieties when possible. Grapes need full sun and strong support for their vines. Regular pruning in winter keeps them healthy and improves yields.

Blueberries are small shrubs that prefer acidic, well-drained soils. They perform best with at least two varieties planted for cross-pollination. Blueberry bushes need a few years to mature but are long-lived. Their berries are high in antioxidants and can be eaten fresh or frozen. Birds also love them, so consider protecting any ripening crops with netting. Learn more about edible perennials like blueberries and others to include in your food forest at this guide to growing edible perennials.

Nut Trees and Their Role in Food Forests

Nut trees are reliable producers of high-calorie foods that also boost biodiversity and improve soil health. Adding them to your food forest helps provide long-term harvests and creates useful shade and habitat for many species.

Growing Nut Trees: Key Considerations

When planting nut trees, make sure you select species that fit your climate and soil. Most nut trees need well-drained soil and good sunlight for healthy growth. For best yields, check if your chosen type needs a pollinator partner. For example, almonds need a second variety for fruit set.

Many nut trees, like pecans and walnuts, are large and take years to mature, but their shade and deep roots can help other plants. Prune young trees to shape them, and give them plenty of space—plan for their mature size from the start. Resist planting them too close together.

Nut trees may need extra water while young but will need less care as they mature. Regularly check for pests and diseases, even if some varieties are hardy. Trees like chestnut and hazelnut handle pests better than others. Starting early gives you a head start on their long wait for nuts—some may not produce heavily for 10 years or longer, so patience is important.

Common Nut Bearing Perennials

Many perennial trees offer reliable nut harvests and support food forest health. Popular types include:

• Chestnut: Sweet, starchy nuts; prefers well-drained, slightly acidic soil; grows tall and resists most pests.
• Hazelnut: Small tree or shrub; tolerant of some shade; quick to mature and easy to grow; nuts are protein rich.
• Almond: Needs two trees for pollination, grows in sunny, dry climates; almonds are high in protein and healthy fats.
• Pecan: Tall tree that loves deep, moist soil; resists drought once established; nuts are rich and flavorful.
• Walnut (English and Black): Needs plenty of space; tolerates heat and drought; used for food and timber.
• Macadamia: Suited to warm, humid places; takes years to bear nuts; offers valuable high-fat harvests.

Other choices—such as butternuts, filberts, and heartnuts—provide different flavors and adapt to a variety of climates. These species support soil structure, more animal life, and long-term food security as part of a layered, thriving food forest.

Shrubs, Bushes, and Berry Perennials

Perennial shrubs and bushes make up the backbone of a productive food forest. These plants provide fruit year after year, help feed pollinators, and are usually easy to grow with the right care.

Blackberries, Raspberries, and Strawberries

Blackberries are hardy perennials that produce sweet, dark fruit in summer. Most varieties grow as canes that need some support, but once established, they offer large harvests with minimal care. Prune dead canes each year to maintain plant health and encourage new growth.

Raspberries are another favorite, thriving in well-drained soil with plenty of sun. They come in red, yellow, black, and purple types. Raspberries spread through underground shoots, so give them space to grow. Regular pruning helps keep the patch under control and the harvest plentiful.

Strawberries form dense, low-growing patches, spreading by runners. They are best started from bare root crowns. After planting, you can expect fruit by the second year. Remove older plants every few years and use their offspring to keep your strawberry bed productive. For more details on growing these essential perennials, visit this comprehensive edible perennials list.

Lesser-Known Berry Bushes

Currants and gooseberries offer tart berries ideal for jams and fresh eating. These bushes tolerate partial shade and colder climates, making them a good choice if your yard isn’t always sunny.

Haskaps (honeyberries) bear early blue fruit with a sweet-tangy taste. These plants are cold-hardy and generally pest resistant. Saskatoon berries and mulberries provide high yields of nutritious fruit on shrubs or small trees. Mulberries in particular are favored for their long lifespan and ease of care.

Some of these shrubs can double as privacy screens or windbreaks in your garden. They support local wildlife, produce berries over many weeks, and need little attention once mature. For a detailed look at hardy berry bushes and their benefits, check out this food forest plant guide.

Essential Perennial Vegetables

Certain perennial vegetables are easy to grow and can reliably return harvests for many years. These plants deliver dependable yields and are often well-suited to a food forest setup, requiring less maintenance after they become established.

Asparagus and Artichoke Varieties

Asparagus (Asparagus officinalis) is a classic perennial vegetable. Once planted, asparagus crowns can produce tender spears each spring for up to 20 years. Asparagus thrives in sunny spots with well-drained soil and benefits from annual mulching.

Globe artichokes (Cynara cardunculus) grow in mild climates and prefer full sun and rich, fertile soils. The edible flower buds of artichokes are picked before they open, providing a tasty and unique vegetable for your table. In colder climates, artichokes might need winter protection.

Growing asparagus and artichokes requires patience, as both take a year or two before you can start harvesting. However, their long productivity and low ongoing needs make them key choices for a perennial vegetable patch. For more on different perennial vegetables, see this helpful list.

Egyptian Walking Onions and Other Alliums

Egyptian walking onions (Allium × proliferum) are unusual perennial onions that form clusters of small bulbs on their stems. These bulbils can be planted to grow new plants, giving them the name “walking onion.” The green tops, immature bulbs, and bulbils are all edible.

These onions survive tough conditions and are highly adaptable. They tolerate various soils and return year after year. Walking onions are among the easiest perennial vegetables to grow, and they quickly expand, allowing you to multiply your crop easily.

Other perennial alliums include Babington’s leek and bunching onions. Both are low-maintenance and add a consistent, mild onion flavor to meals. Any of these choices are excellent for adding resilience and diversity to food forests.</p>

Oca and Jerusalem Art

ichoke

<strong>Oca (Oxalis tuberosa) is a lesser-known perennial from the Andes. Oca is grown for its small, colorful, tangy tubers that are harvested late in the season. It does best in cooler climates and benefits from loose, fertile soil. Tubers can be eaten raw or cooked, adding variety to your harvest.

Jerusalem artichokes (Helianthus tuberosus), sometimes called sunchokes, are hardy and productive perennials. These sunflower relatives produce knobby, edible tubers that are high in inulin. They’re easy to grow, tolerate poor soils, and can reach over six feet tall.

Both oca and Jerusalem artichokes spread via their tubers, so choose a spot where they can expand. Harvesting the tubers in fall reveals a nutritious, starchy food with a crisp texture. These root vegetables are particularly valuable for food security in diverse gardens. To learn more about options for root vegetables and other perennials, visit this in-depth perennial vegetables guide.

Herbs and Medicinal Perennials

Many perennial herbs add flavor to your food forest and some provide healing uses as well. These plants are easy to grow, come back every year, and can serve as both food and natural remedies.

Chives, Mint, and Lovage

Chives (Allium schoenoprasum) are reliable and hardy. You can use the leaves in salads, soups, or as a garnish. Their purple flowers attract pollinators, and the plants tolerate full sun to partial shade with minimal care. Chives are well known for their mild onion flavor and are a staple in perennial herb gardens.

Mint varieties, including peppermint and spearmint, thrive in many soils but spread fast. Mint is great for teas, garnish, and fresh flavor in drinks. For best results, grow it in a pot or use barriers to keep it in check. Unique types like chocolate mint offer unusual flavors. Chocolate mint is popular for desserts and tea.

Lovage (Levisticum officinale) looks like celery and has a strong flavor. You can use the stems, leaves, and seeds in soups and stews. Lovage grows tall and adds structure to planting beds. The leaves taste like a mix of celery and parsley and often get used for seasoning stocks.

Parsley, Rue, and Sorrel

Parsley (Petroselinum crispum) is usually grown as a biennial, but in mild climates, it can survive and return. Both flat-leaf and curly types are popular. Use parsley leaves for garnishes, salads, and sauces because of their fresh flavor and nutrients.

Rue (Ruta graveolens) stands out for its blue-green leaves and herbal bitterness. It has a history as a medicinal plant but is best kept away from kids and pets due to skin irritation risks. Rue’s yellow flowers add color to your food forest, and some gardeners use its scent to deter pests.

Sorrel (Rumex acetosa) is a leafy green with a sharp, lemony taste. The leaves are good for salads and soups, and the plant comes back year after year. Sorrel grows well in partial shade and is one of the first greens you can harvest in early spring.

Echinacea, Wintergreen, and Watercress

Echinacea (Echinacea purpurea), also known as coneflower, is grown for its purple blooms and medicinal properties. It’s used in teas and supplements said to support immune health. Echinacea is drought-tolerant and attracts butterflies and bees.

Wintergreen (Gaultheria procumbens) is a ground cover with glossy leaves and red berries. The leaves are used to make tea with a minty taste. Wintergreen prefers shady, acidic soil. The plant produces wintergreen oil, which you can find in some natural remedies and chewing gum.

Watercress (Nasturtium officinale) grows best in wet soil or even shallow water. It provides peppery leaves that you can harvest almost year-round in the right conditions. Watercress grows fast and offers vitamins A and C. Plant watercress by a pond edge or in a damp area for a steady harvest of edible greens.

Support Species and Soil Enhancers

Support plants in a food forest do more than just fill space. They help build healthy soil, cycle nutrients, and support the entire ecosystem with useful flowers and foliage.

Comfrey and Dynamic Accumulators

Comfrey is a standout perennial that many gardeners use for building soil. Its deep taproots pull up nutrients from lower soil layers, making minerals more available to other plants. You can chop and drop comfrey leaves around trees and shrubs to use as a natural mulch. The leaves break down quickly, adding both nitrogen and potassium to the soil.

Dynamic accumulators are plants that gather specific minerals or nutrients in their tissues. Besides comfrey, other examples are borage, yarrow, and nettles. Planting these in your food forest can help reduce the need for store-bought fertilizers. They also offer organic matter for your compost pile or mulch layer. This makes them useful support species for any permaculture design. Learn more about the role of support plants in food forests at PFAF’s food forest support plants guide.

Key support species for soil health:

• Comfrey
• Borage
• Yarrow
• Nettle

Pollinator Attractors

Attracting pollinators is critical for encouraging fruit and seed production in your food forest. Many perennial plants play a key part in bringing beneficial insects such as bees, butterflies, and hoverflies. For instance, bee balm, lavender, and clover all offer nectar and habitat for pollinators.

When you choose flowering perennials for your garden, look for a mix of bloom times. This keeps pollinators visiting throughout the growing season. Herbs like thyme, oregano, and rosemary also attract helpful insects while providing useful leaves for your kitchen. A diverse mix of flowers, colors, and shapes will give your food forest a stable pollinator population. See a detailed list of perennials with pollinator and soil benefits at Permaculture Women’s food forest perennial vegetables.

Common pollinator-friendly perennials:

• Bee balm
• Clover
• Lavender
• Oregano
• Thyme

Climate Adaptation: Matching Perennials to Your Hardiness Zone

Planting the right perennials for your local climate is vital for developing a stable and productive food forest. Understanding hardiness zones and selecting plants adapted to your area helps reduce losses, saves time, and supports strong, healthy growth.

Understanding Hardiness Zones

A hardiness zone is a geographic area defined by its average minimum winter temperature. In the U.S., the USDA Plant Hardiness Zone Map divides the country into zones, each representing a 10°F temperature range.

Knowing your zone helps you pick perennials that can survive winter where you live. For example, a plant suited for Zone 5 may not make it through a Zone 3 winter. Hardiness zones range from 1 (coldest) to 13 (warmest). To look up your exact zone, check your ZIP code against the most current USDA map.

Gardeners in the same region often share a zone, but local factors like wind, altitude, and snow cover shift temperatures. Keep notes on what survives in your microclimate over several seasons to fine-tune your selections.

Choosing Perennials for Your Region

To match plants to your zone, start by looking for varieties listed as hardy in your area. Many nurseries and gardening resources tag perennials with recommended zones, making it simple to find what fits your region. Lists of zone-appropriate perennials help narrow your choices further.

If temperatures in your area often go below what a plant can handle, it might die back or fail to produce. Focus on perennials that are well-adapted, such as berries, herbs, or nitrogen fixers proven in your climate. For example, currants, sea buckthorn, and hardy asparagus grow well in colder zones, while figs and pomegranates work in warmer regions.

Track plant spacing, soil needs, and sunlight along with zone recommendations for best results. Always watch for new cultivars bred to extend the growing range of classic food forest favorites.

Best Practices for Planting and Managing Perennials

Establishing a healthy food forest with perennials depends on good preparation, smart care, and long-term management. Careful planning leads to strong growth, fewer problems with pests or disease, and more productive harvests.

Site Selection and Preparation

Choosing the right location is the first step to success. Most perennials need at least 6 hours of sun each day, though some, like currants or ferns, can handle partial shade. Check your soil texture and drainage—water should not pool or stay soggy for days.

Test your soil pH before planting and adjust as needed. Many berry bushes do best in slightly acidic conditions, while asparagus and herbs often prefer closer to neutral. Clear the area of sod, weeds, and invasive roots.

Loosen soil to a depth of 12-18 inches. Add compost, leaf mold, or well-rotted manure to increase organic matter and encourage healthy roots. Group plants with similar needs together for easier care. Plan for mature sizes, leaving space so airflow keeps leaves dry and healthy.

Mulching and Soil Health

Mulch helps prevent weeds, keeps soil moist, and feeds your plants as it breaks down. Use wood chips, chopped straw, grass clippings, or shredded leaves. For fruit trees, apply a thick layer of mulch for fruit trees in a wide circle, keeping it a few inches back from the trunk.

Replenish mulch every year or as needed. Avoid using grass clippings with weed seeds or chemically treated material. If possible, apply organic amendments such as compost or worm castings under the mulch for an extra boost.

Monitor earthworms and soil texture as you work, because they show soil health is improving. A healthy mulch layer supports fungi and microorganisms that benefit perennial roots. Over time, this natural layer will reduce the need for fertilizer, improve water retention, and help your plants withstand drought.

Long-Term Maintenance Tips

Caring for perennials requires patience but pays off over time. Water new plantings regularly until established, then gradually reduce frequency. Mature perennials often tolerate dry spells but may still need extra water during hot, dry weeks.

Prune dead or diseased branches to keep bushes and small trees productive. Divide clumping perennials like rhubarb or chives every few years for better growth. Watch for common pests, such as aphids or slugs, and control them with hand picking or barriers.

Remove weeds by hand or with a hoe before they go to seed. Walk your site weekly to spot problems early. In late fall, replace or top up mulch to protect roots over winter. With steady attention, your food forest perennials can thrive and produce for years. For more details, see this guide on perennial garden care.

Frequently Asked Questions

Perennial foods in a forest garden can provide fruits and vegetables for many years with minimal replanting. Choosing the right crops and design helps create a garden that thrives and is easy to care for.

What are the most popular perennial fruits for a food forest?

Apples, pears, and plums are common choices because they grow well in many climates and give good harvests. Blueberries, raspberries, and blackberries are popular berry options that come back year after year. You might also consider strawberries and figs for reliable fruit over many seasons.

Can you provide a selection of perennial vegetables suitable for forest gardening?

Asparagus, rhubarb, and globe artichoke are well-known perennial vegetables. Other good options include sorrel, sea kale, lovage, and Egyptian walking onions. Plants like alpine strawberries and bamboo shoots also add variety to the edible landscape. For more ideas, see this food forest perennial vegetable list.

How can one design a perennial vegetable garden for optimal yield?

Plan for layers, using tree canopies, shrubs, ground covers, vines, and root crops. Plant sun-loving vegetables in open spots and shade-tolerant ones under trees. Group plants by how much water and space they need. Focus on plant diversity and include crops that fix nitrogen, like beans, for better soil health.

Which forest plants thrive best alongside food forest perennials?

Clover, comfrey, and yarrow attract pollinators and support healthy soil. Herbs like thyme, oregano, and rosemary fit well among perennials and repel pests. Native shrubs and small trees, such as hazelnut and elderberry, offer wildlife habitat while complementing food crops in mixed plantings. You may find more about plants for food forest layers helpful.

What perennial fruits and vegetables are recommended for Zone 6?

For Zone 6, consider apples, pears, cherries, and hardy kiwis as fruit options. Blueberries and currants also perform well. Asparagus, rhubarb, horseradish, and chives are dependable perennial vegetables. Sea kale and Turkish rocket survive cold winters and produce every year in this zone.

How can one identify forest plants within a food forest ecosystem?

Pay attention to leaf shapes, growth habits, and where the plants grow. Perennials often have woody stems or a clumping form and return each spring. Many have deeper roots compared to annuals. Look for clusters of similar plants, layered growth, and perennials that maintain green foliage across the seasons.