Easter Sunday morning saw me out in the garden with a lit candle. However, it was not a celebration of the heavenly occasion, but something rather earthier. The candle was being used to seal some holes with wax, which I had drilled into some oak logs to insert dowels impregnated with Shiitake mushroom spawn. These logs came from a helpful neighbor and are stacked in a wet, shady corner of the veggie garden; hopefully to produce a bounty of succulent mushrooms in a few months.
Fungi are an often overlooked but very important part of gardening and indeed life. That Easter weekend seemed to be all about fungi for me; appropriately so, as autumn is the traditional season for harvesting many fungi. I noticed several Shaggy Ink Caps growing through the lawn, these are quite edible, and I expect the big delicious field mushrooms are not far off. Wild harvesting of fungi is best left to experts though, as there are so many dangerous species about – a point underscored by the appearance of several very beautiful, but very deadly, Amanita mushrooms from the potting mix of some plants in our conservatory this week.
Less desirable fungi have quite an impact on gardens as well. Here in the so-called “winterless north”, a long, wet winter like the one we’ve just had can spell doom for many plants. The culprit is usually a water-loving, soil-borne fungus called Phytophthora, which means “plant destroyer” in Greek. There are numerous species of this fungus, which affect a wide range of plants, but in general they all act the same. Plants and trees affected will often look okay over winter – maybe a bit peaky – but as new growth starts in spring they give up the ghost, with sudden wilting, followed by leaf drop, tip die-back, followed usually by death.
There are a range of treatments that can be employed to counter this dreaded disease. Firstly, make sure you have good drainage in your garden, which, incidentally, helps with a range of other problems as well. On flat ground, creating a gentle slope can get rid of some excess water, as can perforated drain pipes installed in the soil. Raising the planting areas even by just a few centimeters can help. All my gardens are edged with timber, most of which was old deck bearers. It’s still good for another decade or so as edging.
Changing the soil ecosystem is the next step. Regular mulching with woody materials helps generate a range of beneficial micro-organisms, which help suppress root diseases. Liming also helps, both to create a less acidic environment, but also to increase the amount of calcium in the soil. Phytophthora doesn’t like soils high in calcium. If the soil is already high pH, which is relatively rare in the north, then applying gypsum instead of lime is recommended as this has very little effect on soil acidity.