Summer heatwave's impact on garden plants

A gardener has detailed the varied impact of this summer's intense heatwaves on their vegetable patch and plants. Records for heat and dryness were broken in August, creating conditions far more intense than previous shorter heatwaves.

You might assume more sun means more growth, but that is not necessarily true. Under heat stress, plants close the pores on their leaves, hindering water movement and gas exchange. This can check growth, and the gardener observed several plants dropping flowers before bearing fruit.

Stressed plants also become vulnerable to pests. This may explain why so many leaf miners targeted the gardener's chard this year. Even established perennials struggled. Golden raspberries, in their second season, had canes that grew well before suddenly turning brown and dying.

Wilting and Watering

The gardener relearned the importance of a plant's wilting point the hard way. They planted out lettuces desperate for space on a 32C day. Although done in the shade of a willow tree, the lettuces had flopped and started to wither by day's end. Targeted watering saved them from the permanent wilting point. However, if more hot weather arrives, the gardener expects them to bolt like a previous round did.

Sun Damage and Soil Issues

High UV levels caused damage and discoloration. Golden marjoram, self-seeded nasturtiums, and newly planted beans all showed leaf signs of sun scald. These are warmth-loving plants. If the damage is confined to a few leaves, removing them can allow the plant to recover and grow normally.

The gardener's clay-heavy soil, prone to compaction, dried out more than usual despite regular mulching. This made it less penetrable by roots. They blame this for the stunted growth of their courgettes, as the bed is unusually solid. With water butts now empty, the gardener is accepting that some crops will offer little harvest.

Survivors and Successes

Yet some plants are doing really well. Special mention goes to the cucumbers in the greenhouse. The grapevine by the back door is also thriving. Most years, it gets mould or mildew before the grapes swell, but the gardener is hopeful for its first real harvest this year.