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Herbaceous perennials are plants that live for more than one year but are not a woody plant such as a tree or shrub. Perennials grow and flower during the spring, summer, or early fall and then die back to the ground during the winter. Although they may produce seeds, these plants rely on vegetative reproduction unlike annuals which reproduce primarily by seed. The different forms of vegetative reproduction structures include bulbs, rhizomes, tubers, and woody crowns. Perennials are better-suited to surviving in colder climates such as Connecticut which ranges from USDA zones 7b to 5b. The larger root systems of perennials allow it to access water and nutrients that may be deeper in the soil making them more drought-tolerant than shallow-rooted annuals may be. Another benefit to perennials is that they will grow for many years with minimal care and do not need to be replaced every spring as annuals do.


Site Selection

Site selection is an important consideration when choosing perennials. While some perennials may adapt to less than perfect sun or shade availability, they may not bloom as abundantly or vibrantly in light conditions that are not optimum for the species. Before any planting, a soil test  will determine any soil amendments that may be needed and will also give fertilizer recommendations. It may be best to select species for the soil conditions that are present rather than to amend soils for a particular plant.

Water Requirements

Regular watering is essential. As with most plants, perennials require about an inch of water at least once a week to keep plants looking good and producing more blossoms. Even drought tolerant species need water to get established and also during long dry spells. Check to see that plants are getting adequate water by either digging down after watering to see how deep the water has penetrated or set out a container and water until the one inch of water is collected. Avoid overwatering established perennials to promote deeper rooting.

Mulching your perennial plantings will keep weeds down and also decrease evaporation as soil under mulched plants will stay moist longer. Any organic material can serve as a mulch but fine-textured shredded bark, cocoa bean hulls or buckwheat hulls may be more in keeping with the scale of smaller annuals. Usually only an inch or so of mulch is necessary around perennials. See Mulch Basics for additional information.

Fertilizer Requirements

In general, fertilizers formulated for flowering plants would contain amounts of nitrogen less than or equal to the amounts of phosphorus (i.e. 10-10-10 or 5-10-5). This is because phosphorus encourages flowering. Too much nitrogen will stimulate green leafy growth at the expense of flower production. Also, the recommendations are made for granular fertilizer formulations. These will generally supply nutrients to the plants for about 6 to 8 weeks. During periods of excessive rainfall or frequent irrigation, the nutrients may be leached out of the soil and fertilizer may need to be reapplied. See Suggested Fertilizer Practices for Flowering Plants for additional information.

Early-season Perennial Suggestions

Variety Bloom Time Height Sun or Shade Comments
Allium, Allium Late spring 12" to 60" Full sun Large globe-like blooms in shades of purple, pink, and blue that can be up 10" wide.
Ajuga reptans, Bugleweed May to June 6" to 9" Full sun to part shade Will grow in full shade but best foliage color will be in part-sun.
Anemone sylvestris, Snowdrop anemone Late spring to summer 12" to 18" Full shade or filtered sun. White flowers with yellow centers, blue-green foliage. Naturalizes easily.
Aquilega, Columbine April to May 18" to 24" Full sun to part shade Spurred flowers that are attractive to pollinators and hummingbirds. Susceptible to leafminers.
Arabis caucasica, Garden rockcress April to May 6" to 12" Full sun White blooms that tolerate gritty but well-drained soils.
Aurinia saxatilis, Basket of gold April to May 6" to 12" Full sun A low-growing, spreading perennial that is very attractive in rock gardens.
Bergenia sp., Saxifrage Spring 12" Full sun to part shade Glossy dark green leaves that turns reddish-bronze, pale pink to ruby red blooms.
Brunnera macrophylla, Siberian bugloss Spring 12" to 18" Dry shade Sky-blue, forget-me-not-like flowers mix well with daffodils. Self-seeder that spreads.
Caltha palustris, Marsh marigold, Cowslip April. May 12" to 24" Part shade, shade Yellow blooms. Prefers boggy areas so plant by a pond, stream, or marsh.
Convallaria majalis, Lily of the Valley Spring to early summer 4" to 8" Part shade Nodding stems covered with tiny, white, bell-shaped flowers. Can spread to many areas.
Crocus, Crocus March to April 6" Full sun to part shade Purple, white, or yellow blooms that will naturalize.
Dicentra, Bleeding Heart Early to late spring up to 36" Full to partial shade An old-fashioned perennial with dangling heart-shaped flowers.
Disporum flavum, Fairy bells, Solomon's seal Mid to late spring 30" Part shade, shade Short-lived, nodding yellow flowers.
Doronicum, Leopard's bane Mid-spring to early summer 12" to 18" Full sun to part shade. Bright yellow daisy-like flowers and heart-shaped foliage. Pairs well with tulips.
Epimedium, Epimedium, Fairy wing's, Bishop's hat April 12" to 24" Light shade Long-lived, shade tolerant groundcover, foliage often evergreen. Blooms in pink, white, yellow, and reddish-rose.
Galanthus, Snowdrop Mid-March 3" to 6" Full sun to part shade So named because it may actually bloom with white, bell-shaped flowers through a cover of snow.
Helleborus sp., Lenten rose Mid-March to April 12" Part sun to light shade Rose-like blossoms in shades of pink to maroon. Glossy evergreen leaves that turn bronze in the winter.
Hyacinthus, Hyacinth Early spring 10" Full sun White, pink, red, pale yellow, and purple very fragrant blooms.
Iris sp., Bearded Iris (Miniature Dwarf, Standard Dwarf, Arils, Spuris) Early to late spring Varied Full sun Many varieties in shades from white to deep purple-black. Grow from rhizomes in well-drained soils.
Lupinus, Lupine Late spring 12" to 48" Full sun Tall, spiky racemes of sweet pea-like flowers in shades of pink, yellow, salmon, blue, and purple.
Muscari, Grape hyacinth Mid-spring 6" to 9" Full sun Deep purple-blue upright stalks of dense bell-like blooms. Will naturalize.
Myosotis scorpioides, Forget-me-not May to October to 24" Shade 5-petaled petite blue blooms that grow well near streams and brooks.
Narcissi, Daffodil Late-march to mid-June 12" to 18" Full sun Long-lived blooms in combinations of white, yellow, salmon, orange, and pink. Will naturalize.
Papaver orientalis, Oriental poppy Late spring up to 36" Full sun Delicate, crepe-paper like blooms that can be up to 6" across.
Peony sp. Mid to late spring 24" to 48" Full sun Bloom time may be extended up to 8 weeks by planting a variety of Peony species.
Phlox divaricata, Wild blue phlox April to June 12" Part shade Pale blue to lavender to violet blooms.
Primula polyantha, Primrose Early spring through summer 18" to 24" Full sun to part shade Wide variety of colors: white, cream, yellow, orange, red, and pink. Do not transplant well.
Pulmonaria, Lungwort Early spring 14" Part to full shade A woodland plant that prefers a shady or moist location. Blue, pink or white flowers.
Pulsatilla vulgaris, Pasque flower April to May 9" to 12" Full shade or filtered sun. Pale or dark violet flowers. Easy to raise from seed.
Sanguinaria canadensis L., Bloodroot March and April 6" to 9" Part to full shade Bloodroot likes to grow along the edge of a wood or stream. Solitary 2" wide white flower.
Tiarella cordifolia, Foamflower May 9" to 12" Part to full shade Easy to grow in moist soils. Pinkish buds open to tiny white flowers.
Trillium sp., Trillium Late winter to early spring 12" to 18" Part shade 3-petaled blooms in shades from white to purple. Plants grown from seed will not bloom for 7 to 9 years.
Viola odorata, Wild violets Late winter to early spring 6" to 8" Part shade Heart-shaped leaves with purple-blue flowers. Naturalize easily.

Mid to Late-season Perennial Suggestions

Variety Bloom Time Height Sun or Shade Comments
Acanthus, Bear's breeches June to August 36" to 48" Full sun to part shade White, pink or purple snapdragon-like flowers on spikes that rise above the foliage.
Achillea millefolium, Yarrow June to September 30" to 36" Full sun White to pink flowers in clusters of 15-40 tiny blooms in a single disc. Deadhead spent flowers to promote additional blooms.
Agastache foeniculum, Anise hyssop Early summer to first frost 24" to 48" Full sun to part shade Upright lavender to purple blooms that are great for pollinators.
Alcea, Hollyhock June to August 72" to 96" Full sun An old-fashioned garden favorite with white, pink, or red blooms growing on tall stems.
Anemone sp., Japanese anemones, Windflowers Late summer, early fall 24" to 34" Full or part sun Delicate masses of 2-3" blooms swaying on slender stems. 6 to 8 weeks of bloom time in shades of white, pink, or violet.
Asclepias, Milkweed June to August 12" to 30" Full sun The many varieties of milkweed provide blooms in white, yellow, pink, and orange that are not only attractive to pollinators but provide food for the caterpillar of the Monarch butterfly.
Aster, Aster Summer to fall 8" to 48" Full to part sun Daisy-like flowers ranging from white to pale pinks and blues to deep pinks and purples. Pinch back before July to control height and encourage bushiness.
Astilbe, False spirea May to June 18" to 24" Part to full shade Fern-like mounds with erect, feathery, plumed flower panicles in pale to dark pink.
Boltonia asteroides, False aster Mid-summer to early fall 48" to 60" Full sun to part shade Clouds of white, yellow, or pink aster-like blooms. Cut back by 1/3 in May and again in July for denser blooms.
Campanula, Bellflower June to July 36" Full sun Upturned, open cup-shaped blooms purple-blue, pink, or white.
Chelone, Turtlehead July to September 24" to 48" Full sun to part shade White to pink flowers, grow in dense spikes. Grows in moist to wet soils.
Chrysanthemum, Mums Late July through October up to 18" Full sun Pinch back new shoots to 2-3 leaves when 6" tall, pinch back again when 12" prior to mid-July to encourage fuller plants. Divide plants every 3-4 years.
Chrysopsis, Golden asters Late summer through fall 18' to 36" Full sun Bright yellow flowers open in late summer and continue through fall. The grey-green leaves are curiously twisted.
Coreopsis, Tickseed Early summer to fall 12" to 24" Full sun, some afternoon shade. Gold, yellow, orange, or red flowers bloom on wiry stems with delicate, narrow foliage. Some varieties may be bi-color.
Digitalis purpurea, Foxglove Summer 36" to 72" Full sun to part shade Stately plants that are suitable for the back of borders. White, yellow, pink, red, lavender, and purple blooms.
Echinacea, Coneflower June to August 24" to 60" Full sun to part shade Showy, daisy-like purple flowers up to 5" in diameter. Best in full sun, divide when overcrowded. Great in borders.
Eryngium planum, Amethyst sea holly June to September 12" to 36" Full sun The silver blue, teasel-shaped flower heads of sea holly are encircled with shiny bracts. Easily grows in dry, well-drained soil.
Eutrochium purpureum, Joe-pye weed July to September 60" to 84" Full sun to part shade Dull pinkish-purple flower clusters, very attractive to pollinators. Seed heads persist into winter.
Heuchera, Coral bells June to July 12" to 18" Full sun to part shade Grown more for the interesting shades of foliage than the slim stems of tiny bell-like flowers.
Hemerocallis sp., Daylily Late spring to fall 12" to 36" full sun to part shade Thousands of cultivars in every color except blue and pure white. Each bloom lasts just a day.
Hibiscus, Hibiscus July to September 48" to 60" Full sun Hardy hibiscus is a woody perennial with large, showy blooms (6"-10") in in white, pink, and red combinations that bloom for one day. Many blooms are open at any time.
Lavandula angustifolia, Lavender June to August 24" to 36" Full sun Gray-green foliage with whorls of tiny, fragrant flowers in purples, pinks, white, and yellow.
Lilium asiatica, Asian lilies June to July 12" to 48" Full sun to part shade Large star-shaped blooms atop long stems, great cut flowers. Susceptible to the Lily leaf beetle.
Lilium oreintalis, Oriental lilies August 12" to 48" Full sun to part shade Large star-shaped blooms atop long stems, great cut flowers. Susceptible to the Lily leaf beetle.
Lobelia cardinalis, Cardinal flower July to September 24" to 48" Full sun to part shade Erect terminal spikes of large, red, tubular flowers. Needs consistently moist soil.
Monarda, Bee balm Summer 24" to 48" Full sun Pink, purple, red, and white spiky blooms that are very attractive to pollinators.
Nipponanthemum nipponicum, Montauk daisy Mid-summer to early fall 18" to 36" Full sun White daisy blooms from mid-summer to frost. Dark green leathery foliage.
Perovskia atriplicifolia, Russian sage Summer 36" to 48" Full sun Showy, tall, airy spikes of lavender-blue flowers with finely-textured foliage.
Platycodon grandiflorus, Balloon flowers Late summer 12" to 24" Full sun to part shade Star-shaped white, pink, or blue blooms from puffy buds.
Polemonium reptans, Jacob's ladder Late spring to early summer 12" to 36" Full to part shade Loose clusters of bell-like flowers in shades of white, pink, yellow, or blue. Low maintenance.
Pycnanthemum sp., Mountain mints July to September 12" to 36" Full sun to part shade Best flowering in full sun, will bloom in bright shade. Pink blooms are a favorite of pollinators
Rudbeckia hirta, Black-eyed Susan June through October 12" to 36" Full sun Large, daisy-like, golden blooms with black centers. Good cut flowers. Does not reproduce true from seed.
Sanquisorba canadensis, Canadian burnet June through October up to 6' Full sun or part shade Great for back of a border with cream colored flowers that resemble bottle brushes.
Sedum sp., Stonecrops August to November 6" to 24" Full sun Hardy succulents with fleshy, water-storing leaves. Great for rock walls and gardens, borders and containers. Divide in early spring.
Solidago, Goldenrod Mid-July to September 36" September to November Tall yellow spikes of tiny yellow blooms, often mistaken for the allergy-inducing ragweed.
Stachys officinalis, Betony July to September 18-24" Full sun An easy-to-grow herb with late-summer spikes of purple flowers that are loved by pollinators
Tricyrtis hirta, Toad lily Late summer to early fall 24'" to 36" Shade Fuzzy, ear-shaped leaves combined with the mottled, curiously shaped mauve flowers at the tips of the stems. Self-seeds.


  • Most perennials will benefit from division every 3-4 years.
  • Spring blooming perennials may be divided in the very early spring, after flowering, or in the fall.
  • Perennials that bloom later in the season can also be divided in the early spring or after flowering.
  • Plants do best if they are divided when the weather is cool and wet to lessen the amount of stress on the plant.
  • Plants should be divided six weeks before the ground freezes to give the plant time to set new roots.
  • Prepare new holes before dividing the mother plant so that roots don't remain exposed to the air and sun longer than necessary.
  • New holes should be twice the width of the root ball.
  • Perennials may be cut back to 6" prior to division.
  • Use a spade or a sharp knife to divide clumps or separate rhizomes.
  • Make sure that the crown of the plants are placed at the same depth in the soil as it was prior to division.
  • Newly divided plants should be watered immediately after re-planting and then receive at least 1" of water per week until the ground freezes.
  • A layer of mulch will help the soil to retain moisture.

Despite good cultural practices, pests and diseases at times may appear. Chemical control should be used only after all other methods have failed.
For pesticide information please call UConn Home and Garden Education Center weekdays, in Connecticut call toll free 877-486-6271. Out of state call 860-486-6271.

UConn Home and Garden Education Center, 2019