I’m no stranger to a hangover. The combined effect of dizziness, dry mouth, nausea and banging headache is all too familiar to me. Those hangover symptoms are, of course, mainly due to dehydration and, in this unusually hot weather, I’m being sensible for a change and taking it easy. While I might be avoiding the effects of dehydration, as this warm, dry weather persists, the plants around me are feeling pretty miserable.
Plants take up water by way of the xylem – a series of tubes which run all through a plant carrying water from the roots, through the stems and into the veins of the leaves. The xylem are like the bones of a plant and, when they’re pumped full of water, the plant is able to stay upright.
In the normal course of events, plants begin work as the sun rises. Tiny pores on the undersides of the leaves (the stomata) open to receive carbon dioxide which is combined with water and, using energy from the sun, converted into sugars and oxygen. With the stomata open to receive CO2, plants also lose water through transpiration. As the day progresses, they are sometimes unable to replace the water lost through transpiration quickly enough. When this happens, they close the stomata and take a siesta until conditions are better. In hot, dry weather, plants must take more breaks and if the drought is prolonged, further loss of moisture causes the xylem to shrink, reducing their ability to stay upright.
My wee seasonal bedding plants on the beach road are in double trouble. Blasted by the hot summer sun and, with the salt-laden sea breeze sucking moisture out of them at an alarming rate, they must be feeling permanently hungover. I first started laying out planted containers on the beach road in front of my house more than ten years ago because I wanted to replicate the look of those pretty Spanish streets with their eclectic collection of colourful pots. Back then, I had only a handful but now I have around fifty.
I have to say, they are coping surprisingly well, happily getting drunk on the increased amount of sugars they are able to make in the sunshine, and I’ve never had a better display of flowers. Every second day, however, their heads drop to let me know they’re feeling lousy. When that happens, it’s out with the watering can and they get between a third and a half of a can each.
Often we are told not to water plants when the sun is shining. The theory behind this advice is that the droplets of water can act like a magnifying glass, burning the leaves. However, if our plants need us, there’s no point in delaying treatment even if only for a few hours. Watering onto the soil is better than not watering at all, no matter what the time of day and especially if the plant is in stress. If the soil is very dry, you might have to water twice – once to hydrate the soil and then again a half hour or so later to hydrate the plant.
For my sweetcorn, green bean, tomato and chilli plants in the polytunnel, where aesthetics isn’t an issue, I have a number of upturned plastic bottles with the bottom cut off and they’re stuck into the soil near the plant roots. I hydrate the soil first and then fill the bottles so my plants have a reservoir of water to help them when I’m not there. I can apply liquid feed into these bottles too in the knowledge the feed will get right to the roots.
Unfortunately, plastic bottles would look pretty ugly stuck into my beach-front bedding plant containers so I have to water them more often. Watering fifty containers with a watering can is no joke but, when I feel like I can’t be bothered, I think about what it’s like to have a hangover and I wouldn’t want to wish that on anything. After all, I’ve been there myself.
The Plant Listener
Explaining the processes upon which all plants rely for their survival and how we can use that knowledge to influence our horticultural practices.
Available in paperback and kindle from Amazon
ISBN No: 978 1 9997243 0 6