How to Grow Perennials

Perennial Flowers Image Gallery Perennials have many uses in the garden. See more pictures of perennials.

Perennials, unlike annuals and biennials, will grow in your garden year after year, bringing consistency to your flowers or foliage.

 

In this article, we'll discuss using color, height, texture, and foliage when designing with perennials; creating perennial meadow gardens; mulching perennials; growing perennials from seeds; growing strawberries; growing perennial vegetables; and growing perennials herbs.

Plant form, color, and texture are important factors when designing with perennials. But the main difference between designing with annuals and designing with perennials is bloom sequence. Annuals tend to bloom all at once, but perennial plants will be in bloom for only a short part of the growing season. One perennial follows another in the annual sequence of bloom, so the focus shifts as the garden changes. It is important to know when to expect each type of plant to flower and which ones are blooming at the same time.

Color is a key element in any flower garden. On the next page, learn about using color in your perennials garden design.

Savory StepsRemove a few bricks in a garden path to make places for low-growing thyme or oregano. Either herb will thrive in this warm, well-drained location and will give a charming natural look and wonderful fragrance to the walkway.

Want more information about gardening with perennials? Try these:

• Perennials: Learn about plants that will continue to grow in your garden season after season.
  
• Perennial Flowers: Plant perennial flowers for years of blooms.
  
• Tips for Growing Perennials: Use these helpful tips to grow healthy perennial plants.
  
• Garden Design: Design your garden for beauty and practicality.
  
• Gardening: Learn the basics of successful gardening.

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Perennials bloom briefly and only once a year. If you would like flower color throughout the entire growing season, plan on a succession of bloom provided by different species. You can do this entirely with perennials, or mix in annuals for additional color from mid-summer to frost. Both tender (such as dahlia) and hardy (such as daffodil) bulbous plants offer additional possibilities. Throughout summer, hardy lilies -- with their varied colors, heights, and forms -- are especially effective in perennial borders.

The yellow coneflower fills your perennial garden with sunshine.

Perennial gardeners strive for a mix of early, midseason, and late bloomers throughout the garden to keep it in constant bloom. As with any artistic endeavor, the right balance is a personal and somewhat subjective decision. For a powerful display, choose two or more plants that will bloom together in a good color combination. Also try to select flowers for all the seasons. Don't clump all the plants that bloom at once in only one part of the garden.

Observe your plantings through the seasons and note where color needs improved balance. Plant large blocks, three or more (many more) plants of just a few varieties together, per bloom period. The bigger the garden, the larger these blocks of plants should be. The balanced masses of color make the garden successful. Note how the garden changes in both color scheme and balance from week to week. A yellow, blue, pale green, and white spring garden may transform into a red, purple, violet, and forest-green one by July, and then go to gold, rusty-red, purple, and bronze shades in September.

Intermixing and underplanting perennials can get complex. It helps to draw up a plan on paper before digging and planting. On graph paper, draw in the band or blob for each group of perennials. After the garden is planted, it will take another year or more to fill in and get established. Spaces between clumps can be filled with annuals while the garden develops.

If your color combinations are not as good as you'd like, move the plants around. If a plant does not thrive, see if it works better under different conditions. If there's a plant you hate or one that dies, get rid of it. If you see a gorgeous perennial that you've never noticed and it grows in your zone and exposure, give it a try. Take a stroll though a botanical garden in your region for ideas about interesting perennials and ways to combine them. Be warned: Words like "addiction" and "obsession" are often used in discussions of gardening with perennials.

Color isn't the only visual effect perennials can bring to your garden. On the next page, learn about using the height, texture, and foliage of your perennial plants when designing a garden.

Want more information about gardening with perennials? Try these:

• Perennials: Learn about plants that will continue to grow in your garden season after season.
  
• Perennial Flowers: Plant perennial flowers for years of blooms.
  
• Tips for Growing Perennials: Use these helpful tips to grow healthy perennial plants.
  
• Garden Design: Design your garden for beauty and practicality.
  
• Gardening: Learn the basics of successful gardening.

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Each perennial has a flowering height and a foliage height. A plant's flowers are usually held up much higher than its leaves. As you design your perennial garden and plan the placement of plants, arrange the garden so that the flowers show and are not covered up by the foliage and flowers of plants in front of them. When the plants in bloom finish flowering and are deadheaded, the unfolding foliage and flowers of other plants help to camouflage the remaining foliage. Long, narrow bands of the same plant give you the most oomph in the least space, as one species supplants another.

Goldenrod gives your garden height and texture.

Consider these varied aspects of your perennials' appearance when designing your garden:

• Form: Plant shape is an important consideration when designing with perennials. If you select plants with varying forms, the garden will be more interesting. Ground-hugging mats; tall, spiked growth; and arching or rounded plants provide visual variety whether the plants are in bloom or not.
  
  
• Texture: A variety of textures adds to a garden's beauty. Placing plants with feathery foliage next to ones with large, bold leaves will produce a more dramatic garden. To test how plants will look when planted together, place potted samples side by side and evaluate them.
  
  
• Pattern: Some plants have foliage or flowers with stripes, spots, and splotches of color, which provide variety to the basic forms. Some flowers are two-toned, with outer petals of one color and inner ones of another, or with several colors on the same petal. Others, like iris, may have upper petals of one color and lower ones of another. Anthers or other flower parts may have colors that contrast with petals.

Another factor is the attractiveness of the foliage itself, with more and more attention being paid to having gardens of leaves of many colors and forms. There are wonderful gardens composed mainly of hostas. Late-emerging hostas combine well with spring wildflowers and bulbs that bloom before the hostas come up. Then the hostas hide the dying foliage of the ephemeral spring plants. From mats of ground-cover ajuga or ginger to towering canna lilies with striped leaves, foliage is a great element of design.

If you want an informal garden design, a meadow garden might be right for you. Keep reading to learn about using perennials to create a meadow garden.

Want more information about gardening with perennials? Try these:

• Perennials: Learn about plants that will continue to grow in your garden season after season.
  
• Perennial Flowers: Plant perennial flowers for years of blooms.
  
• Tips for Growing Perennials: Use these helpful tips to grow healthy perennial plants.
  
• Garden Design: Design your garden for beauty and practicality.
  
• Gardening: Learn the basics of successful gardening.

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A meadow garden showcases blooms in an informal design. There are many easy, sun-loving plants that combine well in broad perennial beds or in fields or meadows. They can even be used instead of a lawn -- if the neighbors don't mind. The soil usually needs some improvement, as it does for any other garden. Cut back the plants after they flower, but leave some of the flower heads on to ripen for self-sown plants, food for the birds, and texture in fall and winter. Cut remaining stalks down to a few inches high, and remove dead leaves in late winter or early spring. Here are some perennials that make a good meadow:

Yarrow plants are excellent for mass plantings.

• Aster
  
  
• Black-eyed Susan
  
  
• Blanket flower
  
  
• Butterfly flower
  
  
• Coneflower
  
  
• Coreopsis
  
  
• Dame's rocket
  
  
• Evening primrose
  
  
• Gayfeather
  
  
• Maiden pink
  
  
• Penstemon
  
  
• Rock cress
  
  
• Shasta daisy
  
  
• Snow-in-summer
  
  
• Wild lupine
  
  
• Yarrow

Like other gardens, perennials gardens will benefit from mulch. To learn about mulching perennials, go to the next page.

Want more information about gardening with perennials? Try these:

• Perennials: Learn about plants that will continue to grow in your garden season after season.
  
• Perennial Flowers: Plant perennial flowers for years of blooms.
  
• Tips for Growing Perennials: Use these helpful tips to grow healthy perennial plants.
  
• Garden Design: Design your garden for beauty and practicality.
  
• Gardening: Learn the basics of successful gardening.

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If you plant perennials in the fall, mulch your new plants with straw or chopped leaves to prevent root damage during winter. A little mulch used immediately after planting can help to keep the soil moist and encourage continued root growth. But the main reason to mulch lies ahead, in winter. Alternately freezing and thawing, expanding and contracting soil can break new roots or even push new plantings out of the ground, a process called soil heaving. By mulching generously with an airy material like straw when the soil first freezes, you can help keep the soil frozen until winter ends, at which point the mulch can be removed.

In winter, mulch evergreen perennials and ground covers with evergreen boughs to protect them from winter burn (the cold weather opposite of sunburn). When the soil is frozen, the wind is strong, and the sun is bright, moisture is pulled out of the vulnerable leaves and cannot be replaced by the frozen roots. A protective layer of evergreen boughs, possibly obtained by recycling the branches of a Christmas tree, forms a protective shield over vulnerable greenery. Straw will also do the job, especially in colder areas where there is less chance of rot in winter.

Growing perennials from seeds isn't hard, as long as you know what kind of treatment your seeds need to sprout. Keep reading to learn about growing perennials from seed.

Want more information about gardening with perennials? Try these:

• Perennials: Learn about plants that will continue to grow in your garden season after season.
  
• Perennial Flowers: Plant perennial flowers for years of blooms.
  
• Tips for Growing Perennials: Use these helpful tips to grow healthy perennial plants.
  
• How to Start a Garden: Find out how to get your garden in the ground and growing.
  
• Gardening: Learn the basics of successful gardening.

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You can grow perennials from seed -- it's not that hard. Perennial seeds are more varied in their germination requirements than those of most annual plants. The sprouts need the right cue from nature before they venture out of their seeds. Some need a cold treatment, which signals winter, followed by a moist, warm period, which signals that spring has arrived. Garden centers, mail-order catalogs and Web sites, and plant societies have good perennial seeds to sell or trade. Some perennials (foxglove is one) have seeds that sprout in days if they are fresh off the plant but go into dormancy if they dry out.

Perennials can be sown indoors or out.

Perennials can be sown indoors or out, but outdoor-sown seeds have a higher attrition rate due to pests and other factors. If you plant seeds of a named cultivar, such as Hosta Frances Williams, which is variegated, you will get baby hostas, but they most definitely will not have precisely the same color and leaf size and shape as their parent. They may grow up to be attractive but different. They will also differ from one another in subtle and not so subtle ways, so a breeder's excitement comes in looking for those few that may be of special interest.

Sow perennial and wildflower seeds outdoors in raised beds or spacious nursery pots (the kind you get big flowers in at the nursery), and let nature get them ready to sprout. Hardy perennials and wildflowers often have a special defense called dormancy that keeps them from sprouting prematurely during a temporary midwinter thaw (which would be damaging when the frost returned). They require a certain amount of cold -- or alternating freezing and thawing -- to indicate that winter is truly over and spring has begun. The easiest way to accommodate the cold requirement is by putting them outdoors.

Another way to give plants a cold treatment is to stratify perennial seeds that require it. Sow them in a community flat of moist seed-starting mix. Label each row with the date planted, the seed source, and the plant name. Wrap the entire flat in a plastic bag and close with a twist tie. Set the flat in the refrigerator for the time indicated on the seed packet or in a seed-sowing handbook. When the recommended stratification time is up, move the flat into warmth and bright light so the seeds can sprout and grow.

For a sweet crop, consider growing strawberries in your garden. Learn about growing tasty and attractive strawberries on the next page.

Want more information about gardening with perennials? Try these:

• Perennials: Learn about plants that will continue to grow in your garden season after season.
  
• Perennial Flowers: Plant perennial flowers for years of blooms.
  
• Tips for Growing Perennials: Use these helpful tips to grow healthy perennial plants.
  
• How to Start a Garden: Find out how to get your garden in the ground and growing.
  
• Gardening: Learn the basics of successful gardening.

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Strawberries (Fragraria species, Zones 3-10 with different types for different zones) are fun to have around for garden tastes, even if the crop is not that large. Various raiders such as birds and squirrels will get most of the crop if you don't keep them out with netting or repellants. The plants like full sun or bright partial shade and moist, rich soil. Buy from local sources for types that thrive in your climate.

Strawberries can flower and produce fruit all summer long.

If you'd like a summer-long harvest, grow day-neutral strawberries. While June-bearing strawberries bear fruit heavily in early summer and ever-bearing strawberries bear in June and again in fall, day-neutrals can keep flowering and fruiting throughout much of the summer.

Plant day-neutral strawberries as early in spring as possible and pinch off all the flower buds for six weeks afterward. This lets the plants grow strong before they begin to fruit. Once the plants are flowering, fertilize them monthly to keep the plants vigorous and productive. Heavy producers such as these may not keep up the pace year after year. When you notice berry production diminishing, consider starting a new strawberry patch with fresh plants.

High-Speed Gardening: Simple Strawberries

Plant strawberries in a strawberry jar for an edible feast on a patio. Strawberry jars stand about two feet high and have openings along the side, perfect for planting with strawberry plants. They look especially charming when little plantlets sprout on runners and dangle down the sides.

Plant in peat-based potting soil mixed with extra compost. To make watering easier, run a perforated plastic tube down the center of the pot before planting. You can pour water down the tube to moisten the entire container from the inside out.

Some common garden vegetables, such as artichokes and asparagus, are perennials. To learn about growing perennial vegetables, go to the next page.

Disease-resistant Strawberries Allstar Cavendish Delite Guardian Lateglow Redchief Scott Surecrop

Want more information about gardening with perennials? Try these:

• Perennials: Learn about plants that will continue to grow in your garden season after season.
  
• Herb Gardens: Grow parsley, sage, rosemary, thyme, and more in your herb garden.
  
• Vegetable Gardens: Find out how to grow a bountiful vegetable crop.
  
• Gardening: Learn the basics of successful gardening.

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A few vegetables are herbaceous perennials that return every year. Vegetable plants need fertile soil and prefer full sun.

Artichokes

In regions with warm winters (Zones 7-11) you may be able to grow true artichokes (Cynara scolymus), as they do in California. Each artichoke is actually the flower of this six-foot perennial, which has what landscapers call "architectural form" -- that is, it is large and bold. Harvest artichokes before the flowers open. If you wait too long, use them in flower arrangements instead of for dinner. Artichokes usually flower their second year and afterward. There are also Jerusalem artichokes (Helianthus tuberosus), which are sunflowers with fleshy, edible tubers. These plants grow 6 to 12 feet tall in Zones 3-10, but there are some shorter cultivars. The late-blooming yellow flowers are attractive. Plants spread quickly.

Asparagus, once planted, takes about four years to become established.

Asparagus

Once planted, asparagus (Asparagus officinalis, Zones 3-8) takes about four years to become established. It grows best in rich soil in full sun. The plants can last dozens of years, and a good asparagus bed is quite a treasure. The spears of established plants are harvested when they are under a foot tall, in spring. At least half of the spears are left to grow into fernlike, leafy stems about four feet tall. In flower borders, fit in clumps of five to seven asparagus plants for double duty as edibles and ornamentals. Do not plow asparagus once it has been planted.

Mulch asparagus every spring with several inches of compost or decayed livestock manure. Asparagus, a greedy feeder, will use all the nutrients it can get its roots on and grow that much better for it. By mulching in the spring, you can fertilize, help keep the soil moist, and reduce weed germination all in one effort. The shoots that arise through the mulch will grow especially plump and succulent.

Perennial herbs can be grown for their looks as well as their culinary uses. Keep reading to learn about growing perennial herbs.

Fancy White AsparagusMake fancy white asparagus spears with a simple blanching basket. When the spears first emerge in spring, cover them with a bucket, basket, or mound of soil that will exclude all light. Harvest when the spears reach eight to ten inches tall and before the ferny leaves begin to emerge.

Want more information about gardening with perennials? Try these:

• Perennials: Learn about plants that will continue to grow in your garden season after season.
  
• Herb Gardens: Grow parsley, sage, rosemary, thyme, and more in your herb garden.
  
• Vegetable Gardens: Find out how to grow a bountiful vegetable crop.
  
• Gardening: Learn the basics of successful gardening.

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Plant perennial herbs in beds and borders in sunny places. Pinch back the tips for bushy plants, but use the parts pinched off for cooking or aroma. Herbs are attractive, easy to grow almost everywhere, and have many uses:

• Sweetly fragrant bee balm has flowers and foliage wonderful for tea or drying for potpourri.
  
  
• Oregano can be short or tall. The leaves have great flavor and are used in stews and pasta dishes. Marjoram has similar growth form and uses.
  
  
• Mint comes in many flavors and types, and it's always nice to have peppermint around for tea. It is rampant in the garden, spreading on long underground runners, so grow it in pots or place it where its spread will not be a problem.
  
  
• Tarragon has narrow leaves and is not as hardy or long-lived as other herbs. It is a good pot plant.
  
  
• Culinary sage plants can have purple leaves; variegated gold leaves; tricolor green, white, and pink leaves; or whitish-green leaves that are a cooling contrast to other plants.

  Thyme is a delicious and aromatic perennial herb.

• Thyme makes hardy mats with many small flowers in summer. The aroma is nice, and the herb is delicious in soups and stews and with beans. There are creeping and upright forms of thyme, and all make good garden plants.
  
  
• Savory has small, delicious leaves that are similar in flavor to thyme. It looks great in a container, by itself or with other herbs.
  
  
• Lavender has flowers for sachets and also for use in herb mixtures, imparting an interesting flavor that people cannot place.

Herbs for Light, Sandy Soil Hyssop Lavender Marjoram Oregano Sage Santolina Sweet fennel Tarragon Thyme Winter savory

Want more information about gardening with perennials? Try these:

• Perennials: Learn about plants that will continue to grow in your garden season after season.
  
• Herb Gardens: Grow parsley, sage, rosemary, thyme, and more in your herb garden.
  
• Vegetable Gardens: Find out how to grow a bountiful vegetable crop.
  
• Gardening: Learn the basics of successful gardening.

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