Planning a border – speaker Mike Burks

SHEPTON MALLET HORTICULTURAL SOCIETY

‘Planning A Border’ by Mike Burks of Castle Gardens, Sherborne, Dorset

3rd February 2016

 

First principle – you can do whatever you like, it’s your garden, but there are some general guiding principles, which may help.

 

  1. Get it down on paper. Especially in winter, when it’s often too cold, wet or dark to get out in the garden, it’s a good time to plot your plans on paper – it makes it easier to evaluate and execute later.

 

  1. Orientation. Which way does the garden face? It will have a significant impact on what plants can be grown where.
    1. South – more daylight and sunshine, quicker to warm up in spring, slower to cool down in autumn.
    2. North – less daylight, more shade, slower to warm up in spring, quicker to cool down in autumn.
    3. East – benefits from morning sunshine, but can be shady later.
    4. West – can be shady in the morning but benefits from afternoon sunshine.
    5. Prevailing winds – south-westerlies bring warm, wet air. Northerly and easterly winds can be very cold.

 

  1. Soil Type. Again this will affect the success of different plants
    1. pH – acidity and alkalinity. Best tested with a pH soil testing kit and distilled water. Don’t be tempted to use tap water or else you are testing the pH of that. You will need to test soil samples from all over your garden for an accurate picture. Ask your neighbours if they know the pH of the soil.

 

Acidic soil is good for Pieris, Rhododendrons, Camelias, Azaleas and Skimmia

Alkaline soil is good for Lavender, Clematis, Geranium, Ceanothus and Campanula

 

    1. Texture – clay, sandy, silty. Dig some up, wet it and roll it in your hand – if you can make a ball from it it’s probably clay, if it feels gritty then it is sandy and if it feels silky then it is probably silty.

 

Heavy clay soils can be waterlogged in winter and baked hard in summer, but they hold a lot of nutrients.

 

Sandy soils are free-draining, can be very dry in summer and don’t hold on to nutrients.

 

The best way to deal with both is to add organic matter, hummus, to break up the clay or knit together the sand – manure, compost, a bark mulch.

 

You can have a combination of different soils in your garden, so can place plants accordingly.

 

Thing of the soil type and aspect of your garden when planting. Convolvulus cneorum is a silver-leafed plant that likes sun on a free-draining (ie sandy) soil. If you plant it in clay in a north facing corner in shade it will not succeed.

 

  1. Local Factors – other features that may influence your garden.
    1. Trees – cast shade, drop leaves, roots take moisture from the soil.
    2. Top of a hill – much more exposed to winds.
    3. Bottom of a valley – can be caught in a frost pocket.

 

  1. Border Shape – this not only affects the style and appearance of the garden but also the ease of maintenance. Some things to consider:
    1. Urban smaller gardens are often geometrical in layout.
    2. Rural larger gardens often have more curves.
    3. The more gentle you make any curves the better and easier they are to maintain.
    4. Walk the person who will be maintaining the garden around to show them your proposed design and listen to their input.
    5. Beware of over intricate or over complex designs that are hard to maintain, eg steeply tapering points in lawns where borders start or finish that cannot easily be mown.

 

  1. Drawing Up Your Plan. If you get it down on paper you can visualise it more easily and work out the plantings.
    1. For an overall garden plan a scale of 1:100 in metric (1cm = 1m), or 1:96 in imperial (1” = 8’) works well.
    2. For a planting plan of an individual bed use 1:50 (2cm = 1m) or 1:48 (1” = 4’).
    3. Graph paper may help you.
  2. Plant Positions. Generally it is advisable to plant taller plants at the back of the border and the shortest at the front so that you get a clear view of them all. If you have an island border you will not want a steep drop off on the far side, so you need to plant your tallest plants about 2/3rds into the bed away from the primary viewing direction and grade down in height from there to all sides.

 

  1. Plant Choice. Some plants perform well for a long season through foliage, stems, colour change, flowers, perfume or a combination of all of them. Others have a shorter season but can be spectacular. In general:
    1. For distant parts of the garden that you are unlikely to venture out to in the cold, wet, dark winter months, these are good places for shorter season plants, as you won’t notice them when they are past their best. Examples include:
      1. Potentillas – fantastic flowers but scrappy when over.

 

    1. For closer parts of the garden that you regularly see, like the front garden, or close to the back door or windows, then think of a combination of longer season plants. Examples include:
      1. evergreen Abelias with gold foliage, colour-changing stems and flowers,
      2. Spirea with early bright foliage, pink flowers in the summer and autumn leaf colour

 

    1. Foliage. When you select your plants think of their foliage first, as this is what you will see for 8-9 months of the year if it is deciduous, or all year if it’s evergreen. These are particularly important at the back of the border. Examples of good foliage plants include:
      1. Elaeagnus ebbingei ‘Gilt Edge’, lots of gold around the leaf, if it produces its small flowers then it is also highly fragrant.
      2. Pittosporum tennuifolium ‘Tom Thumb’, purple low-growing sphere, lovely lime green contrasting new foliage.
      3. Choisya dewitteana ‘Aztec Gold’, fine-leaved, short, tougher than normal choisya, lots of fragrant white flowers from spring into summer, flowers after a cold spell.
      4. Euonymous fortune ‘Emerald ‘n’ Gold’, ‘Emerald Gaiety’, very good evergreen for north facing border, will climb a bit when planted against a wall or fence. In a tough winter it takes on a pinkish hue.
      5. Conifers – much maligned from overplanting in the 1970s and a tendency for some varieties to outgrow the garden, but very useful to give variety in colour, texture and shape. Chamaecyparis pisifera ‘Filifera Aurea’, low growing, loose and shaggy yellow-green, Juniperus horizontalis ‘Blue Chip’, ground cover with lovely blue hue, Thuja occidentalis ‘Rheingold’, it’s large for a dwarf conifer but has great colour change from green to bronze. Taxus baccata ‘Icicle’, slow and low growing (2 feet in 10 years) but columnar and leaves edged in yellow, so a lovely contrast to other plants. There is a tall growing one – Taxus baccata ‘Standishii’. Conifers will cope with clay soils but they don’t want to be sat in water over winter. They are OK in shade and low light but their colours won’t be so strong.

 

    1. Super Evergreens – they have great flowers. Examples include:
      1. Mahonia japonica, cut them low early on to get multiple stems as it’s the stem tips that sprout the fragrant yellow flowers in winter.
      2. Viburnum tinus, very reliable, scented flowers from September to March.
      3. Osmanthus heterophyllus ‘Variegatus’, looks like a holly, highly scented flowers in autumn, will do OK in shade.
      4. Sarcococca hookeriana – Christmas Box. No good at the end of the garden – doesn’t look like anything, keep it near the front or back door for its strong winter scent. ‘Winter Gem’ has larger flowers.
      5. Nandina domestica – Chinese Sacred Bamboo. Grows to around 4’ and has ‘autumn colour’ through the winter. Good shape and texture. It prefers acid soil but will cope in alkaline with a bit more food.

 

    1. Stem Colour and Shape – the stems of deciduous plants can bring texture and variety to the border, especially in winter after the leaves have fallen. Examples include:
      1. Cornus – Dogwoods. Best pruned hard in the spring to promote new growth, which is what colours up the strongest in winter. Cornus alba ‘Elegantissima’ – lovely red stems, some with variegated leaves. Cornus alba ‘Kesselringii’ is vigorous with black stems. Especially good is Cornus sanguinea ‘Midwinter Fire’, which is not so vigorous (so shouldn’t be pruned so hard) but whose leaves fade to white in autumn and stems are shades of gold, salmon and red.
      2. Corylus avellana ‘Contorta’ – contorted hazel. Best in the winter after leaf fall as the leaves, as well as the stems, are contorted and so look diseased. Lovely catkins in winter as well as nuts in autumn.

 

    1. Berries. Pyracantha ‘Teton’, red berries after small white flowers, Cotoneaster also vert useful.

 

    1. Flowers. Plot individual plants on paper. Think about the combination of plant colours and shapes next to each other and after you have the structure, backbone and foliage sorted use flowers for added impact. Good examples include:
      1. Potentialla – profusion of bright flowers
      2. Euphorbia – Efanthia & Glitter Blue – good foliage and flowers
      3. Nepeta racemose/mussini – silver foliage (wants hot, dry, sunny)
      4. Lamium maculatum ‘Beacon Silver’ – a very good dead nettle for winter containers
      5. Stachys byzantina – Lamb’s Tongues
      6. Pulmonaria – Lungwort. Late winter/early spring, spotted leaves and flowers from blues through pinks. ‘Opal’ and ‘Trevi Fountain’
      7. Heuchera – more or less evergreen and clump forming – loads of colours – ‘Peach Crisp’ and ‘Liquorice’
      8. Bergenia ‘Overture’ – evergreen with leathery round leaves, erect cluster of pink flowers in spring

 

    1. Numbers and Spacing – too many small single plants can look patchy, so plant in groups, odd numbers can look more natural, eg 3, 5 or 7. When thinking of distances between plants you need to be pragmatic – official planting distances may be good in five year’s time but that’s a long time to wait – compromise by planting a little closer but be prepared for extra maintenance – dividing, thinning, pruning or moving down the line.Notes by Dominic Weston

      Many thanks to Mike Burks of Castle Gardens http://www.thegardeneronline.co.uk/