Tuesday, October 9, 2007

Gardens in the cool and shade

In deep shade, where even weak shafts of sunlight do not penetrate, very few plants will grow. As a general rule, if the shade is too deep for you to read comfortably, then it is too dark for plants. However, a certain amount of shade provides ideal conditions for some plants that will not grow happily elsewhere. Ferns, hostas, impatiens and periwinkles (vinca) are all shade lovers. If they are grown in too much light, their leaves will scorch and their flowers fade fast, or the whole plant may shrivel up and die. However, not all shade-loving plants need the same degree of shade - some need full shade, others only shade from strong, midday sun and others dappled shade - and many of them grow in more than one type of shade.

On a plant label, 'shade' can mean good light but no direct sun, except weak evening, early morning or winter sun - many ferns will flourish in this position. 'Light shade' means that the plant likes light, but not direct sun. 'Partial shade' usually means that the plant needs sun for part of the day; for example, gardenia and Japanese anemone both enjoy a few hours of sun but prefer shade in the middle of the day. Japanese maple (Acer palmatum), azaleas, japonica camellias, clivia and native violets prefer the dappled shade found under a light tree canopy - such as that of an open gum tree - where rays of weak sunshine are able to break through. Although few flowering plants thrive in this situation, you can add colour by growing brightly toned hydrangeas, impatiens and fuchsias in containers.

Beneath big deciduous trees, shade is very deep in summer and the soil is dry and impoverished because the trees take up all the moisture and nutrients. The ground will also be full of tree roots so there is virtually no soil in which to plant. In cool climates, the best solution is to mulch the ground deeply and to plant spring bulbs - such as daffodils, jonquils or bluebells -that flower and complete their life cycle early, before the trees come into leaf.

Another testing type of shade is year-round, deep shade with dry soil, along a passageway or under evergreens, for example. Plants that tolerate this include Hovea lance-olata, mondo grass and several mintbushes (Prostanthera). In deep shade with damp or wet soil, grow tree ferns (Dicksonia antarctica).

In shade on a boundary, go for Aucuba japonica, Eranthemum pulchellum or aspidistra and, to cover the ground and suppress weeds, plectranthus, Indian strawberry (Duchesnea indica), or Ajuga reptans.

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