The word prairie means grassland – specifically of the American Midwest. However, the term as a garden style has come to include plantings that consist not only of North American grasses and flowering

Perennials are any plant living for at least three years. The term is also commonly used for herbaceous perennials which grow for many years (To compare: annual = one year, biennial = two years).

You could design a plant scheme based on a South African meadow or Mediterranean maquis, but in other examples, plants within the same project may originate from varying parts of the world. As long as the climatic conditions and soil conditions are similar, they can be successfully combined.

The methods described are suitable for establishing naturalistic plantings in borders in medium-sized gardens but much larger areas given over to this style have the greatest impact.

This style of planting offers enormous opportunities for wildlife, from providing nectar and pollen from late-flowering

Perennials are plants that live for multiple years. They come in all shapes and sizes and fill our gardens with colourful flowers and ornamental foliage. Many are hardy and can survive outdoors all year round, while less hardy types need protection over winter. The term herbaceous perennial is used to describe long-lived plants without a permanent woody structure (they die back to ground level each autumn), distinguishing them from trees, shrubs and sub-shrubs.

The ideal time to plant is March. Some planting could be carried out in September, but this would not suit warm season grasses. In March the soil is starting to warm up and all plants will have the whole season to establish.

Timing of seed sowing depends on the seed mix or your custom choice of seeds. Choose species with the same germination requirements.

There are two ways in which you can do this; each creates a different style.

1. By planting established grasses and flowering perennials in drifts or blocks of varying proportions. Although always evolving, the plantings are redolent of a traditional border.
2. By broadcast sowing, to create ecological communities. Competition between plants is natural and planting changes continuously over the years. This is more akin to true prairie.

In general, choose a site that receives full sun for most of the day.

1. Planting a prairie-style border

This interpretation of prairie planting is closer to the traditional perennial border, which has always used prairie plants such as phlox, golden rod (Solidago), Monarda and asters. With the addition of ornamental grasses, you can enjoy an area inspired by the prairies.

Advantages

• Ideal in smaller areas
• Planting well-developed plants gives them a head start in establishment and resistance to pest damage
• Planting in drifts and blocks makes identifying weeds easier than establishment from seed

Disadvantages

• Needs as much maintenance and management as a traditional herbaceous border
• Less dense than a seeded prairie, so there are more opportunities for weed seedlings and over-dominant plant species to get a hold, changing the character quickly of the border if not regularly maintained

How to prepare the ground

Ensure the ground is absolutely free of perennial weeds such as couch grass, ground elder, bindweed and dandelions.

Rotovate the ground if you are creating a border on a new site, incorporating a 7.5cm (3in) layer of well-rotted garden compost or manure.

Design and planting

Next you can build up your palette of plants to suit the conditions. Within these constraints, you can make your design choices.

• Decide how much sun the proposed planting area receives
• Decide the soil type
• How long must flowering last and when would you like the main display to be?
• Aim to include variety in flower shape and flowering time – daisies, spires, round, spiky, umbrella-like and ethereal ‘see-through’ plants
• In small areas, plant in informal drifts of at least five plants. Drifts can be variable in shape, but are usually longer and thinner than blocks and can give an attractive naturalistic impression
• Make use of back lighting to show off grasses and other ‘see through’ plants, as opposed to a fence. Island beds work well
• Choose plants that will provide interest throughout the growing season, which means planning in layers. Start with a low understory of spring perennials with a mix of taller perennials to follow, with flowering progressing through to autumn
• Choose a mixture of both species and cultivars of plants to lend a feel that is as naturalistic as possible
• Try to repeat groupings to give coherence and rhythm
• Annuals, biennials and bulbs also have their place

In a larger space, you can use a ‘matrix’ planting technique. This is a principle of Piet Oudolf, one of the main proponents of this style of planting. He ranks plants according to visual impact.

1. The matrix is a species, planted in large numbers that acts as the background, pulling the whole mix together. It is often, but not always a grass.
2. Planted among the matrix are groups or drifts of strong or ‘primary’ flowering plants. These offer the main interest in terms of colour and structure.
3. Finally, add scatter plants add a natural, random feel. Verbascum would be an example of a scatter or ‘secondary’ plant.

Aftercare

• While plants are establishing, apply a deep mulch of at least 75mm (3in) bark, gravel or wood chips
• Water thoroughly at least twice a week through the first couple of growing seasons
• Weed regularly, before they seed
• Cut prairie-like foliage down in spring so that plant material accumulated through winter acts as a mulch to supress early germinating weeds

2. Prairie plant communities from seed

The most naturalistic way to establish a prairie planting is to sow seed. The aim is to create low maintenance ecological communities. The main characteristic of this type of planting is the intermingling of plants. They are not grown in blocks or drifts of species, but scattered. It requires a certain amount of knowledge and observational skill to establish and maintain such plantings. Researchers and designers, James Hitchmough and Nigel Dunnett have spent many years developing this novel approach to gardening, based on semi-natural vegetation types, which has become known as the ‘Sheffield School’ of planting design.

Examples can be seen in the Merton Borders at Oxford Botanic Gardens by James Hitchmough and London Olympic Park designed by Nigel Dunnett and James Hitchmough.

Advantages

• A genuine plant community is established that evolves over time and will resist weeds better once mature because plants are more densely packed
• Cheaper than planting plants
• More species can be included, therefore extended flowering is possible
• Makes good use of sites with low fertility

Disadvantages

• Much weeding maintenance at first
• Slugs are not a problem in many drier climates, but they find seedlings and young plants in the UK’s damp conditions, irresistible

Assess the limitations of the site

• How much sun and shade is there? You may need to create different zones with varying conditions
• Soil type – how well-drained is your soil?

Decide on the look of the planting

• How long must flowering last and when would you like the main display to be?
• Also consider heights of plants – those emerging later in the season will shade out lower layers – will these be tolerant of shade?
• Aim for all the plants to be cut down at the same time

Once you can answer these questions, you can start to choose the seed mix for these conditions, or you can make your own customised mix. You can do this by researching the seed supply websites. Ensure that the seeds used to create mixes all have the same germination requirements and can be sown at the same time.

Choosing plants from the same geographical location means you have a chance they will all grow together well. However, if you combine plants from geographically diverse areas, you can achieve the ideal colour combinations and greater longevity of flowering.

To avoid grasses becoming too dominant, you can add them afterwards. There is a list of seed suppliers at the end of the page.

A considerable amount of maintenance is required to establish seed-grown prairies, and depending on conditions, certain plants may assume dominance.

How to prepare for seed sowing

1. The area you are to sow must be completely free of all vegetation, especially perennial weeds. The most organic approach to removing this plant cover, is by hand. This can take a year or more to eliminate persistent weeds. Eradication of weeds such as couch grass or bindweed would respond well to use of a systemic herbicide allowing you to sow soon after treatment.
2. If the area was lawn, it is likely to be compacted, so dig or rotovate to the depth of a spade’s blade and level carefully with a landscape rake.
3. To prevent annual weed seeds germinating from the seed bank already in the soil, lay a layer at least 75mm (3in) deep of washed sharp sand on the surface before sowing.

Sowing

• Mark out the area to be sown with string, making grids of m²
• Mix seed thoroughly with a two handfuls of a carrier such as damp sawdust at a rate of 1-2g per m² (3½-7oz per 10.8sqft)
• Broadcast seed with carrier (such as kiln-dried sand or sawdust shavings), making two passes over the area in differing directions to obtain good coverage
• Using a wide landscape rake, incorporate the seed into the top by raking in two directions at right angles to each other
• It can be useful to lay open-weave jute netting over the area to prevent digging by cats, squirrels or badgers. This is also useful when seeding onto a slope
• Add in some mature plants if necessary

Creating a prairie from seed can be very cost effective, but some perennials may be difficult to grow from seed or take too long. Buying and planting a few container-grown specimens amongst the prairie may also mean that a better choice of cultivars is available. Do this before laying the sand mulch and sowing seed.

• When planting, remove 2-4cm compost from the top of plant containers; this removes the seed bank on the compost surface

Aftercare

• Water the whole area thoroughly every two or three days for the first season
• Implement a slug deterrent programme
• Weeding – in early summer, it is easier to identify any young weed seedlings and to remove them
• After the second year, thinning out dominant species will be necessary, so good observation skills are useful

Prairie-style borders in open sunny, well-drained areas

cv = cultivar

Grasses

Tall
Miscanthus sinensis cvs
Calamagrostis cvs
Stipa gigantean AGM
Panicum virgatum cvs

Short
Molinia caerulea  and cvs
Deschampsia caespitosa and cvs
Anamanthele lessonia AGM
Pennisetum aloepecuroides and cvs
Hakonechloa macra AGM
Stipa tenuissima 

Umbellifers (umbrella-shaped flowers)

Anthriscus sylvestris ‘Ravenswing’
Angelica gigas
Cenolophium denudatum AGM
Chaerophyllum hirsutum ‘Roseum’
Eryngium species and cvs

Daisies

Echinacea purpurea and cvs
Rudbeckia species and cvs
Helenium autumnale cvs
Helianthus species (perennial)
Symphyotrichum laeve 'Calliope'
Anthemis tinctoria cvs

Spires

Salvia × sylvestris cvs
Lythrum salicaria cvs
Veronicastrum virginicum cvs
Verbascum species
Perovskia atripicifolia 'Blue Spire' AGM
Eremurus cvs
Stachys officinalis ‘Hummelo’ AGM
Solidago rugosa 'Fireworks' AGM

Round/globe-shaped

Echinops bannaticus cvs
Phlomis fruticosa AGM
Phlomis russelliana AGM
Allium cvs

General

Oenothera species
Phlox cvs
Hemerocallis cvs
Iris sibirica and cvs
Knautia macedonica and cvs
Cirsium rivulare ‘Atropurpureum’ AGM

Components of seed mix for open, sunny, well-drained area

Prairie seed mix (James Hitchmough mix available through Jelitto - see Further information)

Eryngium yuccifolium
Echinacea pallida
Oenothora macrocarpa ssp. incana Silver Blade® 
Oenothera tetragona
Liatris aspera
Agastache rupestris
Andopogon scoparius
Baptisia australis var. minor
Symphyotrichum oblongifolius
Asclepias tuberosa
Dianthus carthusianorum
Silphium laciniatum
Scuttellaria baicalensis
Silphium terebinthinaceum
Rudbeckia missouriensis
Rudbeckia maxima
Rudbeckia fulgida var. deamii
Geum triflorum
Euphorbia corollata
Penstemon barbatus ssp. coccineus
Penstemon strictus
Phlox pilosa
Penstemon cobaea
Penstemon digitalis 'Husker Red Strain'
Dracocephalum rupestre

Places to see prairie planting

Hermannshoff, Germany
West Sussex Prairie Garden
Merton Borders, Oxford Botanic Garden
RHS Garden Wisley 
Trentham Gardens 
London Olympic Park

Books

Sowing Beauty: Designing Flowering Meadows from Seed by James Hitchmough (Timber Press 2017, ISBN 9781604698022)

Planting: A New Perspective by Piet Oudolf and Noel Kingsbury (Timber Press 2013, ISBN 9781604697315)

Natural Garden Style: Gardening Inspired by Nature by Noel Kingsbury (Merrrell 2009, ISBN 9781858944432)

Suppliers of seed

Jelitto
Pictorial Meadows
Prairie Moon
Prairie Nursery
Silverhill Seeds

Sundries

Jute netting