While we all love the rain across our region in the last couple of months, continued wet weather does highlight some parts of our gardens that are poorly drained and this can be a challenge for keeping plants alive under such conditions. Physical solutions such as installing subsurface drainage pipes or digging small channels to collect and divert water away from poorly drained sites in the garden are one option, as is raising the garden beds by building up the soil or installing structures such as steel or timber garden edges.
My preferred option though is to find plants that will tolerate “wet feet”-this is probably the best long term solution for parts of the garden that are prone to poor drainage. Perennial plants that will handle wet feet include oyster plant (Acanthus), ajuga, Blechnum ferns, Siberian iris, mint, Arum lily and bog sage.
Shrubs or small trees that are suited to wet soil conditions include a few Australian natives. Most Australian native plants are not at all suited to wet or boggy conditions and will die quicker than most plants under such conditions. However, a few bottlebrushes such as Callistemon citrinus (crimson bottlebrush), C. pallidus (lemon bottlebrush) and C. viminalis (weeping bottlebrush) are naturally suited to these conditions, as are Melaleuca (paperbarks). Mahonia is a hardy “exotic” shrub that can also handle wet soils.
Larger trees that you might consider for wet spots in the garden include Australian natives Casuarina cunninghamiana (river she oak) and Casuarina glauca (swamp oak). Swamp cypress (Taxodium) is an interesting deciduous conifer that has great foliage colour in autumn and can tolerate wet feet on the edges of swamps, dams, ponds or streams. More traditional ornamental trees that can handle periods of wet growing conditions include golden elm, silver birch, tortured willows and pin oaks.
By Ian Rogan
Millthorpe Garden Nursery