Tuesday 24 April 2018

Diarmuid Gavin: How to manage pests in your garden

Take the natural approach and rid your garden of pests with these chemical-free homemade solutions

Garden pests - natural remedies are at hand
Milk and water can prevent blackspot
Chamomile tea
Barrier - eggshells
Baking soda
Nematodes can be bought in powdered form

Diarmuid Gavin

We are right in the middle of the growing season now and, as gardeners, we have definite expectations of beautiful floral displays in our borders, and vegetable and fruit gardens being packed with ever-swelling produce.

Garden plants attract all sorts of bugs and diseases, and with this season enjoying some damp and muggy conditions, it has created an ideal environment for pests and diseases to take hold. This week I've been dabbling in 'alternative medication' for the garden, testing some environmentally-friendly homemade concoctions to ensure that I keep some pests at bay.

Good general garden practice with careful maintenance is a good way to start. When planning a garden, make sure your soil is well-conditioned, and ensure that whatever you plant likes the site and situation you provide. This will provide a strong base for your plants and give them every chance of being healthy.

If you need to treat plants by spraying, do this in the early morning, or on a warm day, in the cool of evening. I will be advocating some homemade remedies so always test on a small portion of the plant and wait 24 hours to observe any results.

Whether you are feeding plants or treating them, always use the recommended dose, never more or less, and with bugs and disease, treat only the area which needs treatment.

Whether it's a homemade lotion or shop-bought preparation, protect yourself with proper clothing and face mask. So, off into the kitchen we go to see what we can cook up for the good of the garden!

Garlic as a fungicide & insect repellent

In your NutriBullet or other food processing device, blend until finely chopped a head of garlic, add 3 cups water, 2 tablespoons of rapeseed oil and a lemon. Leave overnight and filter through a cloth the next day. Mix at 4 tablespoons to a gallon of water and spray affected areas.

Baking soda spray

This can be used on leaf blight, powdery mildew and as a general fungicide. Use at the first sign of infection. Wash down the plant with water first to dislodge as many spores as possible. Then mix 1 tablespoon baking soda with 2 and a half tablespoons vegetable oil and a gallon of water. Shake up and add half a teaspoon of Castile soap and spray. The mix may separate when in the sprayer so keep the contraption moving. Repeat once a week if necessary.

Milk and water for blackspot

Who would have thought that a simple spray consisting of one part cow's milk to two parts water could be effective against blackspot, which can ravage roses in our sometimes warm, wet conditions? Seemingly it changes the pH on the surface of the leaves making them less susceptible to mildew and other fungal infections.

Powdered cinnamon for damping off

This is another very simple treatment for those wishing to protect young seedlings from being attacked by fungal infections at their most vulnerable stage. Simply sprinkle the soil surface with some of the powder. It only needs to be done once and won't harm the foliage if it touches it.

Chamomile tea for damping off

Chamomile is a concentrated source of calcium, potash and sulphur. The sulphur is a great fungus fighter, so by creating a solution (chamomile tea) it works as a wonderful safe fungicide. Make an infusion with three chamomile teabags and allow it to steep for 15 minutes. Mist the seedlings using a spray bottle once they start to sprout.


Nematodes are tiny parasitic creatures which burrow into other slightly bigger creatures such as vine weevil. They release harmful bacteria and destroy them within a day or so. They are not harmful to humans, pets or plants but only work when the soil temperature warms up. August and September are ideal months for application. You buy the nematodes in powder form and dissolve in water and spray affected areas.


Slugs and snails are the bane of every gardener's life. Try using up your leftover coffee beans and crushed eggshells to create rough barriers around precious plants. Copper bands are also effective around pots, giving snails a mild electric shock if they try to cross.

This week in the garden:

Windy and sunny days make plants thirsty. Prioritise fruit and veg as these need regular watering for good crop development. Anything in containers and pots are relying on you, so may need twice daily drinks. Don’t worry too much about the lawn — it will recover the fastest. Any newly planted trees or shrubs should also be watered daily. Damp down your greenhouse, and open doors and windows to increase ventilation.

Ponds may need topping up if their levels are sinking.

Collect seedheads from your favourite flowers and pop in paper bags to dry out inside — remember to label the bags as you do it.

Hopefully you are harvesting in your veg garden but you may also still be sowing seeds — lettuce, beetroot, Swiss chard, spring onions, swede as well as herb seeds. If it’s too hot, consider erecting a canopy over the veg plot using sheets and bamboo sticks.

Lemon trees and other citrus fruit trees need feeding throughout the summer.

Make sure to leave time to enjoy your outdoor space and admire your gardening efforts!

Weekend Magazine

Life Newsletter

Our digest of the week's juiciest lifestyle titbits.

Editors Choice

Also in Life