Perennials for Sandy Soils: A Toronto Master Gardeners Guide

Perennials such as blue spirea (Caryopteris) – shown here in two foliage variations – and purple Russian sage (Perovskia) can make dramatic additions to the well-drained, sandy garden. Photo: Helen Battersby

Perennials are plants that renew themselves each year from their hardy roots. Some plants live for only 2-3 years while others last a long time. Although there are woody perennials, such as trees and shrubs, the plants most people refer to as perennials are herbaceous meaning they have soft stems. Most die back to the ground at the end of the growing season, but some are evergreen.  All re-emerge each spring to grow and bloom. thespruce.com/what-is-a-perennial-flower-or-plant-1402789

Advantages of Growing Perennials

Planting perennials saves gardeners time and money. They offer excellent value as they only have to be planted once for years of enjoyment. Once established, they require less annual maintenance.

Because the root systems of perennial plants grow and spread each year, they are able to access water and nutrients further down in the soil. Therefore, they require relatively less fertilizer and water. These deep roots also support soil structure and help to prevent soil erosion.  

Perennials provide an amazing variety of both flowers and foliage. There is a range of forms and sizes to suit any site. They will grow in a wide range of soil conditions and have varied light requirements. Perennial plants add colour and texture to the garden in every season. From early spring through late fall they continually change the appearance of the garden as different plants come into bloom.

Uses for perennials

Perennials can form the basis of garden beds and borders or serve as an eye-catching specimen plant, which creates a focal point in the garden.

Low growing perennials can be added to define the edges of beds or borders, create boundaries between adjacent properties or line walkways.

Ground covers such as creeping phlox and perennials with deep root systems, planted on hillsides, will decrease soil erosion.

Perennials can serve as thrillers, fillers and spillers in containers. Thrillers Fillers and Spillers. Container Gardening.  thrillersfillersandspillers.com

Characteristics of Perennials for Sandy Soils

Sandy soils can be hot, dry, and low in nutrients. They are fast draining and therefore, dry out quickly. This aspect is a plus for many plants. However, it can also mean that sandy soils can be too dry for some plants. Ideal candidates for sandy soils are plants that prefer poor, dry soils and are heat and drought tolerant.

Although most of the metro Toronto area has clay soils (nutrient rich and slow draining), sandy soils are found in the Beach, East York and Etobicoke. Most of the perennials that thrive in hot, dry, sandy situations require full sun, which means a minimum of six hours of direct late-morning or afternoon sun. Plants that will tolerate dry shade or semi shade conditions have also been included in the plant list that follows.

What to Consider When Choosing Perennials for Sandy Soils

It is important to choose plants that match your growing conditions to minimize maintenance and maximize plant performance. Water shortages, water-use restrictions and warmer temperatures are factors leading gardeners to consider purchasing drought-tolerant plants which grow well in sandy soil.

Within a genus of plants, not all species or cultivars have the same cultural requirements. For example, although most Artemisias are heat and drought tolerant, Artemisia lactiflora (white mugwort) prefers a moist site. Before choosing cultivars or varieties from the same genus, check the plant label for light, soil and moisture requirements.  Plant labels also list the range of hardiness zones where plants can flourish. It’s important to know how cold it typically gets in your area and whether a particular plant is hardy enough to survive those temperatures.

When choosing perennials, it is desirable to select plants that are not invasive.  Invasive plants have been introduced by human action to areas outside their natural region and may cause harm to the environment, economy and society including human health. These plants grow aggressively and without any natural enemies can spread from gardens to surrounding areas, potentially destroying native habitats. Grow Me Instead, a guide listing common invasive plants and non-invasive and native alternatives is available online at ontarioinvasiveplants.ca/resources/grow-me-instead.

Increased awareness of the need to provide shelter, pollen and nectar for bees, butterflies and other insects has prompted gardeners to incorporate and even substitute native species into their gardens.

Native plants have formed symbiotic relationships with native wildlife over thousands of years, and therefore offer the most sustainable habitat. A plant is considered native if it has occurred naturally in a particular region, ecosystem, or habitat without human introduction.

Many native insects rely exclusively on one native plant to exist.  For example, Asclepias tuberosa (butterfly milkweed) is the exclusive diet of Monarch butterfly larvae.

Foliage from natives provides food for a relative greater variety of caterpillars, the main food source for young birds.  Also, native plants attract beneficial insects that are natural enemies to many garden pests. 

Care and Maintenance

Improving the soil before planting will ensure that the perennials perform well for years in the garden. It will also allow for a wider variety of plant choices.

Before planting new perennials, you should amend dry sandy soils with 10 to 15 centimetres of organic material, composted manure, compost, or leaf mould. This will add nutrients and improve the ability of the soil to hold moisture. When adding organic material, do not dig the amendment into the soil. This will disturb the soil profile, established over many years by every-present soil microorganisms. Instead, top dress the planting area with the organic material, and let the worms and other tiny creatures do their work.. Remove all weeds before planting.

A layer of organic mulch will keep the soil cool and moist, reduce water requirements and lessen weed germination. As well, it improves soil structure, increases mychorrhizal diversity, and feeds the plants when it breaks down. Shredded bark, compost, and pine needles make good mulches. 

Newly planted perennials, even those that are drought tolerant once established, need to be watered at planting time. Then water every week for the first two weeks and during periods of drought. For the first year, all perennials will benefit from regular watering so that they can become successfully established. Because sandy soils are relatively coarse, they cannot store water as well as clay soils. Therefore, it is advisable to water sandy soils with smaller quantities of water applied more frequently than with clay/silt soils.

Monitor and pull out weeds as they germinate and while still young to prevent them from setting seed. Deadhead perennials to prolong bloom.

Monitor your plants regularly for potential problems. For aphids and spider mites, spray with water. Always dispose of diseased foliage in the garbage, not the compost pile. Look for perennials that are noted for pest and disease resistance.

It is beneficial, rather than lazy to postpone fall cleanup of perennials until late spring, when temperatures are above 10 degrees C. Seed heads provide food for birds. Insects, frogs and other small creatures overwinter in the remaining dead leaves and hollow stems. Branches left standing help hold snow around the base of the plant, insulating the roots from cold or freeze and thaw cycles. The shapes and textures of plants left  standing add beauty to the garden in winter. Decomposing leaves nourish the soil.

Growing perennials in sandy soil, though sometimes challenging can be very rewarding.

Perennials for Full Sun

  • Achillea millefolium ‘Paprika’ or ‘Terracotta’(common yarrow); hardy to Zone 2; 45-75 centimetres tall; September bloom (native)
  • Achillea millefolium ‘Moonshine’ (common yarrow); hardy to Zone 3; 45-60 centimetres tall; October bloom
  • Anaphalis margaritacea (western pearly everlasting) hardy to Zone 3; 30-60 centimetres tall and wide, July-August bloom (native)
  • Antennaria dioica ‘Rubra’ (pink pussy toes); hardy to Zone 1; 10-15 centimetres tall; June bloom; evergreen
  • Anthemis tinctoria ‘Sauce Hollandaise’ and ‘Wargrave Variety’ (golden marguerite daisy); hardy to Zone 2; 30-45 centimetres tall; August bloom
  • Arabis alpina subsp. caucasica ‘Snowcap’ or ‘Rosea’ (rock cress); hardy to Zone 3; 15-20 centimetres tall; June bloom; evergreen
  • Armeria maritima ‘Dusseldorf Pride’ (common thrift); hardy to Zone 2; 10-15 centimetres tall; June bloom; evergreen
  • Artemisia ‘Huntingdon’ and ‘PowisCastle’ (wormwood); hardy to Zone 5; 60-90 centimetres tall
  • Asclepias tuberosa (butterfly milkweed); hardy to Zone 4; 60-90 centimetres tall; August bloom(native)
  • Aurinia saxatilis ’Citrina’ (perennial alyssum or basket-of-gold); hardy to Zone 3; 20-30 centimetres tall; June bloom
  • Baptisia australis ‘PurpleSmoke’ (false indigo); hardy to Zone 4; 90-120 centimetres tall; June bloom
  • Buddleia davidii ‘Potter’s Purple’ and ’White Profusion’ (butterfly bush); hardy to Zone 5; 120-480 centimetres tall; October bloom
  • Carlina acaulis subsp. simplex bronze form (friendly thistle); hardy to Zone 3; 30-45 centimetres tall; July bloom
  • Caryopteris x clandonensis ‘Worcester Gold’ and ‘Longwood Blue’ (blue spirea); hardy to Zone 5; 60-90 centimetres tall; October bloom
  • Coreopsis verticillate ‘Moonbeam’ (thread-leaved coreopsis); hardy to Zone 4; 30-45 centimetres tall; September bloom
  • Dianthus x allwoodii  ‘Bath’sPink’ and ‘MountainMist’ (border pinks); hardy to Zone 3; 20-30 centimetres tall; July bloom; evergreen
  • Echinacea purpurea ‘White Swan’ and ‘Magnus’ (coneflower); hardy to Zone 3; 75-90 centimetres tall; late summer bloom (native)
  • Eryngiumplanum ‘Sapphire Blue’ (blue sea holly); hardy to Zone 4; 60-75 centimetres tall; August bloom
  • Gallardia x grandiflora ‘Mandarin’ or ‘Goblin’ (blanket flower); hardy to Zone 2; 50-60 centimetres tall; September bloom
  • Geum triflorum (prairie smoke); hardy to zone 3; 15-45 centimetres tall; May-June bloom (native)
  • Lavandula augustifolia ‘Munstead’ (lavender); hardy to Zone 4; 30-40 centimetres tall; August bloom
  • Liatris spicata ‘Floristan Violet’ or ‘Florisan White’ (blazing star); hardy to Zone 2; 75-90 centimetres tall; September bloom (native)
  • Limonium latifolium (sea lavender / statice); hardy to Zone 2; 60-75 centimetres tall; August bloom
  • Linum perenne ‘BlueSapphire’ (blue flax); hardy to Zone 2; 25-30 centimetres tall; August bloom
  • Lychnis coronaria ‘Angel’s Blush’ (rose campion); hardy to Zone 3; 60-90 centimetres tall; August bloom
  • Nepeta racemosa ‘Walker’s Low’ or Nepeta ‘Dropmore Blue’ (catmint); hardy to Zone 2; 30-40 centimetres tall; September bloom
  • Oenothera fremontii ’Lemon Silver’ (evening primrose); hardy to Zone 4; 10-15 centimetres tall; August bloom
  • Origanum laevigatum ‘Herrenhausen’ (ornamental oregano); hardy to Zone 4; 30-60 centimetres tall; October bloom
  • Papaver nudicaule ‘Flamenco’ or ‘Champagne Bubbles’ (Iceland poppy); hardy to Zone 2; 30-45 centimetres tall; October bloom
  • Penstemon barbatus ‘ElfinPink’ or ‘PrairieDust’ (beard-tongue); hardy to Zone 3; 30-45 centimetres tall; August bloom
  • Perovskia atriplicifolia (Russian sage); hardy to Zone 4; 90-150 centimetres tall; October bloom
  • Phlomis tubersoa ‘Amazone’ (sage-leaved mullein); hardy to Zone 2; 90-120 centimetres tall; August bloom
  • Phlomis fruticosa (Jerusalem sage); hardy to Zone 5; 60-120 centimetres tall; July bloom
  • Phlox douglasii ‘Crackerjack’ or ‘Rose Cushion’ (moss phlox); hardy to Zone 2; 60-120 centimetres tall; May bloom; evergreen
  • Potentilla thurberi ‘Monarch’s Velvet’ (red cinquefoil); hardy to Zone 4; 30-40 centimetres tall; September bloom
  • Ratibida columnifera (prairie coneflower); hardy to Zone 2; 60-90 centimetres tall; September bloom
  • Rudbeckia Hirta (black-eyed Susan); hardy to zone 3; 30-80 centimetres tall; July-September bloom (native)
  • Salvia x sylvestris ‘Caradonna’ or ’Mainacht’ (syn.’MayNight’) (perennial sage); hardy to Zone 3; 45-50 centimetres tall; July bloom
  • Salvia verticillata ‘Purple Rain’ (whorled sage); hardy to Zone 3; 40-45 centimetres tall; August bloom
  • Santolina chamaecyparissus (cotton lavender); hardy to Zone 6; 30-45 centimetres tall; July bloom; evergreen
  • Scabiosa columbaria ‘Butterfly Blue’ (pincushion flower); hardy to Zone 4; 30-45 centimetres tall; October bloom
  • Tanacetum niveum ‘Jackpot’ (snow daisy); hardy to Zone3; 30-45 centimetres tall; October bloom
  • Thymus ‘Doone Valley’ (thyme); hardy to Zone 4; 5-10 centimetres tall; August bloom; evergreen
  • Verbascum ‘Helen Johnson’ (mullein); hardy to Zone3; 75-90 centimtres tall; August bloom
  • Veronica prostrata ‘Aztec Gold’ or ‘Trehane’ (speedwell); hardy to Zone 4; 10-15 centimetres tall; June bloom
  • Veronica whitleyi (Whitley’s speedwell); hardy to Zone 3; 5-10 centimetres tall; June bloom; evergreen

Perennials for Part Sun/Part Shade

  • Aster divaricatus (white wood aster); hardy to Zone 3; 45-90 centimetres tall; September – October bloom; (native)
  • Anemone cylindrica (thimbleweed); hardy to Zone 4; 30-60 centimetres tall; May – June bloom; (native)
  • Aquilegia canadensis (wild columbine); hardy to Zone 4; 60-90 centimetres tall; May- June bloom; (native)
  • Eupatorium rugosum ‘Chocolate’ (boneset); hardy to Zone 5; 90-120 centimetres tall; October bloom
  • Euphorbia myrsinites (donkey tail spurge); hardy to Zone 5; 15-20 centimetres tall; June bloom; evergreen
  • Euphorbia polychroma (cushion spurge); hardy to Zone 2; 30-45 centimetres
  • Gaura lindheimeri ‘Whirling Butterflies’ or ‘Siskiyou Pink’ (butterfly gaura); hardy to Zone 5; 90-120 centimetres tall; October bloom [since the early 2000s known as Oenotherea lindheimeri ]
  • Geranium sanguineum (bloody cransebill); hardy to Zone 3; 30-40 centimetres tall; summer bloom
  • Helianthus divaricatus (woodland sunflower); hardy to Zone 3; 60-180 centimetres tall; July bloom; (native)
  • Hemerocallis ‘Happy Returns’ or ‘Apricot Sparkles’ (daylily); hardy to Zone 3; 45-60 centimetres tall; continuous bloom
  • Iberis sempervirens ‘Snowflake’ (candytuft); hardy to Zone 3; 20-25 centimetres tall; June bloom
  • Persicaria affinis ‘Dimity’ (dwarf fleeceflower); hardy to Zone 3; 15-20 centimetres tall; August bloom
  • Pulsatilla vulgaris ‘Papageno’ (pasque flower); hardy to Zone 2; 15-30 centimetres tall; May bloom
  • Sedum (Herbstfreude Group) Herbstrfeude (syn. ‘Autumn Joy’) or ‘Purple Emperor’ (stonecrop); hardy to Zone 2; 30-60 centimetres tall; October bloom
  • Sempervivum ‘Purple Beauty’ or ‘Thayne’ (hens and chickens); hardy to Zone 1; 5-10 centimetres tall; August bloom; evergreen
  • Stachys byzantina ‘Helene von Stein’ or ‘Primrose Heron’ (lamb’s ears); hardy to Zone 3; 30-45 centimetres tall; evergreen
  • Teucrium chamaedrys ‘Summer Sunshine’ (germander); hardy to Zone 4; 15-20 centimetres tall; August bloom; evergreen
  • Tradescantia ohiensis (Ohio spiderwort); hardy to Zone 4; 60-90 centimetres tall; June bloom; (native)

Perennials for Part Shade/Shade

  • Symphytum ibericum (yellow-flowered comfrey) – hardy to Zone 4; 20-30 centimetres tall; July bloom
  • Waldsteinia ternata (barren strawberry) – hardy to Zone 3; 10-15 centimetres tall; April bloom; evergreen

Note: Many lists of perennials for sandy soil will include perennials such as  Japanese spurge (Pachysandra terminalis), yellow archangel (Lamiastrum galeobdolon) and spotted dead nettle (Lamium maculatum). These invasive plants can spread into natural areas and have an adverse effect on local native plants. For this reason, they are not recommended. For information about invasive plants and non-invasive alternatives, see the link below to the Grow Me Instead brochure.

References

The Spruce. What is a perennial? https://www.thespruce.com/what-is-a-perennial-flower-or-plant-1402789

Ontario Invasive Plant Council. Grow me instead. http://www.ontarioinvasiveplants.ca/resources/grow-me-instead/

National Wildlife Federation. About native plants. http://nwf.org/Garden-for-Wildlife/About/Native-Plants

Tallamy, D. Bringing Nature Home. How you can sustain wildlife with native plants. Timber Press, 2009

Chalker-Scott, L. Mycorrhizae. So, what the heck are they anyway? MasterGardener online 2009 Winter. https://s3.wp.wsu.edu/uploads/sites/403/2015/03/mycorrhizae.pdf

Johnson L. 100 easy-to-grow native plants. Revised third edition. Douglas And McIntyre (2013) Ltd., 2017

Missouri Botanical Garden.  Plantfinder (various plants) https://www.missouribotanicalgarden.org/plantfinder/plantfindersearch.aspx

Valleau, John. Perennial Gardening Guide. Valleybrook International Ventures Inc., 2003

DiSabato-Aust, Tracy. The Well-Tended Perennial Garden, Planting and Pruning Techniques.  Timber Press,1998

Heritage Perennials  https://www.perennials.com

Date Revised: February 2022

Prepared by the Toronto Master Gardeners, these Gardening Guides provide introductory information on a variety of gardening topics.  Toronto Master Gardeners are part of a large, international volunteer community committed to providing the public with horticultural information, education and inspiration.  Our goal is to help Toronto residents use safe, effective, proven and sustainable horticultural practices to create gardens, landscapes and communities that are both vibrant and healthy.

Statement on Invasive Plants: When choosing plants, avoid invasive plants, which can spread quickly and dominate gardens.  Invasive plants are sold by nurseries, big box stores or even at community plant sales.  Invasives may already be present in your garden.  They can invade gardens by spreading from under a neighbour’s fence or may be transported by wildlife.  For beautiful, sustainable options to invasive plants, see the Ontario Invasive Plant Council’s “Grow Me Instead – Beautiful Non-Invasive Plants for your Garden” at https://www.ontarioinvasiveplants.ca/resources/grow-me-instead/before purchasing or accepting “gifts” of plants.

Statement on Home Remedies: The Toronto Master Gardeners do not recommend home remedies, as these have not been proven effective through scientific investigation, and may even damage other living organisms in the soil or plants in your garden.  There are other garden friendly options you can use.

If you have further gardening questions, reach us at our gardening advice line 416 397 1345 or by posting your question here in the Ask a Master Gardener section.  To book Toronto Master Gardener volunteers for talks, demonstrations, advice clinics, or other services, please contact us at 416 397 1345  or bookamg@torontomastergardeners.ca