Gardening with Kitty: don’t let garden visitors bug you

As our summer reaches its climax, July is the month when our vegetable gardens are teeming with growth and harvests. But we are not the only ones excited by the abundance.

High-summer is a key time to keep a close eye on potential pests and imbalances in your garden. From green aphids clustering on lettuce to cabbage white butterflies flitting around brassicas, many other creatures are just as eager to enjoy our crops as we are.

Rather than aiming to eliminate every threat, the goal should be to understand pest life cycles and stay a step or two ahead in order to protect pickings and the natural ecosystem. Managing pests is as much about adopting the right mindset as it is about using the right methods. After all, some would argue that we humans are the pests and the one’s upsetting the natural balance of the garden.

Notable garden visitors

Cabbage white butterflies: The name ‘cabbage white’ commonly refers to two visually similar but distinct species of beautiful white butterflies. Although harmless in their own right, their caterpillars voraciously devour cabbage and other members of the brassica family.

The larvae of the large white are distinguished by their yellow and black patterns and heavy infestations will potentially defoliate entire crops. Small white larvae (green caterpillars) feed alone and often burrow into head-forming brassicas, leaving holes and visible droppings as signs of their presence.

Aphids (greenfly and blackfly): Aphids are small, soft-bodied insects that suck the sap from leaves and stems, often clustering on the tips of new growth and undersides of leaves. Aphids are known to reproduce rapidly which leads to exponential population growth that will weaken plants and spread disease, especially in July’s warm conditions.

Carrot root fly: This specialist pest is attracted by scent and lays eggs near the base of carrot plants. The larvae burrow into the roots, rendering the crop discoloured and inedible. The second and often more damaging generation of this fly typically emerges in July.

Slugs and snails: Though more notorious in spring and autumn, slugs and snails can still be active in a damp Irish July, particularly under leafy canopies. Young seedlings of direct sown crops are at risk.

Birds: We gardeners have a mixed relationship with birds. We appreciate when they predate on pests and help pollinate, but it’s frustrating when they clear a whole crop of berries, grain or leafy greens.

Prevention and planning

The key to pest control is prevention, observation and to encourage balance using a gentle, nature friendly approach.

Physical barriers: Netting, such as fine mesh insect netting is an effective defence against cabbage whites. Ensure the net is raised above the leaves and secured at the edges so butterflies can’t slip through or lay eggs through the mesh. Equally, fruit bushes will benefit from netting when berries are ripe for enjoying.

Fleece or enviromesh: These can deter a variety of flying insects, including carrot root fly and aphids, especially if positioned directly after sowing.

Encourage natural predators: A healthy garden is a balanced ecosystem so it is important to include flowers strips and leave wild areas and native plants flourish. These will provide essential habitat for beneficial insects such as parasitic wasps, ladybirds and lacewings, who in turn will feast on aphids.

Including beetle banks in a garden also provides a habitat for ground beetles, natural predators of slugs. And nothing beats a small pond for encouraging frogs and a wild messy corner for hedgehogs which are other allies against slugs.

Strategic planting is said to confuse or repel pests. Combining carrots with onions to mask their scent is a classic example, but it’s not foolproof. The best companion plants to a vegetable garden are flowers, especially natives, so retain as many as possible to attract beneficial insects.

Of the non-natives, Tagetes or French marigold are a popular companion flowering plant as their scent is known to deter aphids and whiteflies whilst attracting beneficial hoverflies. There are lots of varieties to chose from with Tagetes tenuifolia being my marigold of choice for edging beds.

Tackling it naturally: Despite our keenest eye and best efforts, pests sometimes get the upper hand.

Hand-picking is an old-fashioned but effective way of coping with aphids, caterpillars and slugs. Check under leaves for cabbage white eggs and squash them before they hatch. Remove caterpillars or larger slugs by hand.

Hand-squashing aphids also helps but these move in armies, so a soapy water spray will be more effective.

A mild solution (a teaspoon of eco-friendly soap in a litre of water) can help reduce aphid populations when sprayed directly on them. Add some garlic for extra protection and avoid spraying in direct sun to prevent leaf burn.

Work with nature, not against it:

Accepting a few nibbles here and there is part of the whole organic process. Rather than waging war, aim to build a resilient balanced system that encourages diversity and supports predators in your summer garden.

I’ve heard of side-shooting tomatoes, but I’m not sure what it involves or which shoots to remove? - Brian, Mullingar.

To keep tomato plants healthy and productive, some intervention is essential. For cordon (indeterminate) types, tie plants to supports and regularly pinch out side-shoots from leaf axils to maintain a single vine and encourage fruit growth. Remove lower leaves up to the first fruit truss for better airflow and light.

Bush (determinate) varieties don’t need side-shooting, but still require support as fruit develops. Simple materials like string and bamboo canes work well. With the right care, and depending on variety and sowing date, you can expect your first ripe tomatoes to be ready for harvest in the coming weeks.

Module/tray sowings for transplanting in polytunnel: Put cucumber, French bean (dwarf and climbing) and basil in modules for later planting into polytunnel beds.

Module/tray sowings for transplanting outdoors next month: Sow cabbage, calabrese, cauliflower, celery, chard, courgette, Florence fennel, kale, purple sprouting broccoli, parsley and winter leeks now to transplant next month.

Direct sow outdoors: Beetroot, carrots, peas, radish, turnip, spring onions and continuous sowings of salad leaves can all be sown directly into well-watered ground.