Peter Dowdall says invest wisely in plants that will help repel the effects of poor drainage and mildew
If ever there was a year to look at the soil in our gardens, then this is it. We have had an untold amount of rain over the first few months of 2018 and as a result many of the plants are suffering. It’s not the rainfall per se that is causing the damage, but insufficient drainage that is keeping the water around the root zone of plants and creating soggy ground.
This in turn can lead to root rot and other fungal problems which will, or may already, have manifested themselves as unsightly spots on the leaves and die-back on stems and leaves. A solution of copper sulphate mixed with water applied now as a broad-spectrum fungicide should help to prevent a lot of the infections.
I got a tip recently from Paul Kirwan of the garden centre in the Homeland store in Ballaghadereen and he assures me that a mixture of one part milk and one part vinegar or lemon juice mixed with ten parts of water works well as the free radicals released by the milk are toxic to fungi. I might just try that this year too.
If your soil has suffered from being a bit wet this spring, but it drained away as soon as it dried up, then there’s no need to panic as I don’t think I know of any garden that didn’t hold water this spring. However, if this is a more frequent occurrence, or your ground took much longer to dry out, or perhaps hasn’t yet, then I think more drastic action than using an organic fungicide may be necessary.
I live on top of a hill, so I can be pretty confident that my garden will be among the first to dry out, but for those who garden on lower levels, then adding something to the soil to aid drainage will certainly help. I’m a great believer in adding horticultural grit to nearly all growing media, as soil can never be free-draining enough and I think a good rule of thumb when planting is to always add a shovel or two beneath the plant.
It just helps to draw moisture away from the roots during periods of excessive rain, but still allows root development and access to the water below in times of drought. You could also look at putting in a good drainage system to take excess water away from the garden.
However, if the water table regularly comes up to meet you on the surface of your lawn, I would suggest that such an endeavour may be, quite simply, a waste of money. It can’t drain anywhere if the water table has risen to the level of your garden.
It goes back to nature, pointless trying to work against her, far more beneficial to try and work with her, (for she will surely win the battle anyway) and use plants that don’t just tolerate damp and wet conditions, but actually delight in them.
Trees, such as Willow, Alder and some species of Birch and Poplar will help to soak up a lot of the moisture from the soil. The same design considerations need to be considered when picking plants for such a garden, elements like structure, texture and colour are involved, but when you are choosing the plants, go for those that will tolerate the ground conditions.
It’s not only trees that will help to dry out the soil, shrub dogwoods with their masses of coloured stems which bring the winter garden to life with colour, will thrive in these conditions and so too the star of the late summer garden, hydrangea.
Many herbaceous plants require a damp or water-logged soil to give of their best and these include the beautiful, ferny leaved Astilbes, which, in a planting scheme will contrast fantastically with the broader, flat and rounded leaves of Hostas, providing masses of colour during the summer and autumn months.
Keep an eye out too for Sanguisorba and in particular a variety called ‘Pink Brushes’. If you can’t get this particular variety then my advice is to simply buy one in flower that you like — for the quality of flower varies hugely depending on variety.
Perhaps you may find the right variety for you at the Fota Plant Fair which takes place at Fota House tomorrow, Sunday, April 22.
Many ferns and grasses too are suited to these conditions along with other perennials for summer colour such as Geums, Rodgersia, Darmera, Lobelia cardinalis and the dramatic, if vigorous Lystichon or Skunk Cabbage.
Many of these are enthusiastic plants to say the least, that is they will spread at will if happy in their situation, so care may need to be taken when choosing particular varieties and in time to halt their gallop.
So, save the money that you may have been putting aside for an expensive drainage system and invest instead, wisely, in plants that will help to alleviate the situation.