Plants for dry shade - 27 March 2018

Mavis wrote:

When I thought about this subject I thought it would be so limited that it would take little time to prepare.  Big mistake.

Finding suitable plants and cross references became quite complicated.  Also I have no technology skills and always resort to books.  As my French is limited I started looking in all my English gardening books but quickly realized that dry shade gardening in the U.K. bears no resemblance to our conditions here.  Even the great Beth Chatto’s advice on suitable plants and the lovely photographs in her book would not be achievable here.  So what to do?  Panic!! Then I found my 2015 catalogue from Olivier Filippi in Mèze, Languedoc-Roussillon, France’s greatest authority on Mediterranean gardening.

He is well known in the U.K. and has written in the RHS magazine as he holds the French National Collection of Oleanders but better still he has a passion for Cistus – my greatest love. It is a pity it is so far away although it is possible for a day trip. I will give details about his nursery at the bottom of the blog. 

Who has dry shade?  So lets get started.

Plants for Dry Shade

This is probably the most difficult situation to plant successfully in a garden.  There are several factors to consider.

• The cause of the shade. Is it the north side of the house or a building. Is it at the foot of a hedge or under trees?
• The following applies particularly to shade under trees.  These are mainly our native trees – Chêne Vert, Chêne Blance and various evergreens often in the pine family.
• I admit that I have only 2 little patches of dry shade despite the fact of having quite a few Chêne Vert, 1 large deciduous tree and 1 large pine tree.
• I am south facing on restanques with olive trees so most of the garden is sunny.. If the shade is behind the house this is not so difficult as if you wish to have a bed you can dig deep, enrich the soil and it will have some rain.
• The depth of shade controls the dryness of the soil for three reasons.

1. The tree canopy allows little water through.
2. It also shades the sun from the plants and soil, but depending on the time of day may allow a little sun to filter through.
3. If the shade is caused by trees there is the problem of their roots taking available moisture and nutrients.

A rule of thumb is if grass and weeds won't grow in this area you will have to retire gracefully.

What can we do about this?

First find what type of soil we have. Mostly in our area the soil is alkaline (calcaire), but if the shade is caused by pines or some other evergreens the soil is invariably acidic, so it is a good idea to use a soil testing kit. There are many plants that can survive in soil which is alkaline through to lightly acidic.

Clear all grass and weeds.  If possible it is a good idea to dig gently to loosen the soil taking care not to damage tree roots.  If there are spaces you can then make pockets for planting.  Preparation and planting are best done in Autumn or Spring.

Next:  Mulch Mulch Mulch

Mulches are essential as the soil may be compacted and impoverished.

Mulches include home made compost, leaf mould, finely chipped bark, grass cuttings that do not include herbicides and are preferably rotted down, manure and coir.

It is also possible to put a sheet mulch down such as black sheet plastic, bonded fibre fleece or even many layers of newspaper.  These will need holes cutting in for each plant, having worked out the arrangement of plants.

It is recommended that mulches should, if possible, be to a depth of 10 cm.

Use an enriched potting compost when planting.  I would be inclined to put a sprinkling of bone meal. Also make sure that you have soaked the plants themselves before planting.

If you still have problems with the soil or the planting especially if it is acid consider sinking a pot to whatever depth is possible or even a piece of art can make the area less dull.

Suitable Plants

If the space is large and can take shrubs put these at the back and any climbers behind them if there is the support of a wall, fence or tree trunk.  Small bulbs and flowers to the front with taller perennials behind – if possible the perennials should be in at least groups of three, all depending on space.

Ground cover plants should be interspersed over the area.  Don’t forget if these become too invasive just thin them out.

Bulbs and Corms

Anemome blanda

Cyclamen hederifolium                    not Cyclamen persicums

Cyclamen mirabile 

Chionodoxa

Ipheion

Pushkina

Erantis hyemalis (Winter Aconite)

Small Perennials

Violets

Hepatica nobilis

Ajuga

Oxalis

Catananche caerulea

Cymbalaria muralis

Lamium

Ferns

Adiantum pedatum

Athyrium niponicum

Blechnum penna-marina

Cryptogramma crispe

Dryopteris

Polypodium vulgare glycyrrhiza

Polystichum

Ground Cover

Vinca Minor

Vinca Major

Hedera alger

Hedera helix

Bergenia

Lamium (Dead Nettle – Various)

Large Perennials

Acanthus Mollis

Agapanthus campanulatus

Bergenia

Coronilla emerus

Centranthus ruber (red, white or mauve)

Geranium macrorrhizum 

Geranium sanguineum

Geranium cantabrigiense

Helleborus argutifolius

Helleborus corsicus

Helleborus foetidus

Glechoma hedracea

Euphorbia martini

Euphorbia characias

Euphorbia mellifera

Shrubs

Buxus balearica

Buxus sempervirens

Cistus creticus alba

Cistus aguilarii

Lonicera etrusca

Mahonia aquifolium

Pitttosporum tobira

Phillyrea

Photinia ‘Red Robin’

Pistacia lentiscus

Ruscus aculeatus

Salvia rosmarinus

Sambucus nigra

Teucrium chamaedrys

Teucrium lucidrys

Nandina domestica

Viburnum tinus variagata

Climbers

Hedera

Clematis armandii

Jasminum nudiflorum

Lonicera japonica 

Lonicera chinensis