Claire Mummery: How to prune your plants in summer for better harvests

Pruning help control garden pests. Photo / Getty Images.

While pruning is a gardening task most typically associated with the winter months, pruning summer crops has been an essential part of my gardening journey over the past three years.

Paring back my fruit and veg during the sunny months has enabled me to minimise disease and control unwanted pests, so here are my tips to prune effectively in your summer garden.

Pest organisms are clever little things and it’s worth understanding their life cycles in order to find and prevent them more effectively.

When insects lay eggs, it is usually on the underside of leaves. This is to keep their eggs and young safe and undetected, and to provide them with an immediate source of food when they hatch, ready to munch their way through our leaves and young vegetables.

When the eggs hatch, the young usually start to suck the goodness out of plants and the plants quickly weaken, becoming more susceptible to disease.

This is where a regular leaf pruning ritual can really help. Removing leaves on a regular basis enables the grower to minimise pest outbreaks and plant stress, as you will usually find cocoons, eggs or even young pests under these leaves.

In my experience, the vegetables that benefit most from a summer prune are beans, cucumbers, melons, pumpkins, zucchini and tomatoes. I have found this to be the most effective and efficient under the larger cucumber, melon and pumpkin leaves, often revealing pest colonies I have been able to control.

Pruning the right leaves is important, but reasonably simple. A simple rule I follow is to avoid taking any leaves that sit directly above fruit, as these serve as cooling shade, and prevent sunburn. I also leave enough for photosynthesis to occur in the plant, usually 2-4 leaves is sufficient.

In my experience, the vegetables that benefit most from a summer prune are beans, cucumbers, melons, pumpkins, zucchini and tomatoes. In controlling pests, I have found this to be an effective pest control under the larger cucumber, melon and pumpkin leaves, often revealing pest colonies I have been able to control.

I wait until the plant is established and has produced its first fruit before beginning to pluck leaves. After this, I will prune off, on a fortnightly basis, any leaves that look unhealthy, have changed in colour or are curled up.

Always remember to look underneath for cocoons and squash these before putting in the compost or bokashi, to prevent hatching. Cut leaves off close to the stems with a sharp knife or scissors. Do this on a dry day, preferably with a light wind, as this will enable the wound to heal quickly and prevent disease from entering the plant.

If your leaves are diseased with powdery mildew or mosaic virus, I would recommend spraying with a good oil before removing to help stop the diseases spreading through the air as you move them.

For tomato plants, I recommend a slightly different approach. I always snap the bottom 30cm of leaves off to create airflow and then only leave the leaves covering the tomatoes. I always snap the leaves off on a windy dry day, remembering to give the plant enough time to dry out before the evening arrives.

If these leaves are disease-free, place them in a bucket of water and leave for 24 hours, then use the water to feed the tomato plants, which they absolutely love. My grandfather taught me this incredible trick.

Remember to water your plants at the base only, so the roots can absorb straight away and you avoid burning your plants. This will also help with disease prevention.