Have you ever wondered why we need to water our plants. Really wondered rather than simply do it? Knowing why we do it and how to do it helps us as gardeners – whether that means how we choose our plants in the first place and match them to our garden’s characteristics, how we might try to alter the climate within our garden or how to
water our plants when the time to do eventually arrives…….
Water in our plants serves 4 main purposes:
If we’re growing our plants from seed then it helps in the germination phase. Water makes the protective covering – the seed coat – soften and allows the ovule to germinate. Sometimes we soak our sweet pea seeds to help them on their way.
Water is also a vital ingredient in the process of photosynthesis (along with sunlight and carbon dioxide). Photosynthesis is needed by our plants to enable them to produce energy so that they can grow.
The transfer of nutrients from the soil and into our plants is enabled by the water – a bit like blood in our own bodies.
Water also helps keep our plants upright! The technical name for this is transpiration. The water in each cell creates pressure that means the plants don’t wilt. A sign of the plant needing water is when they’re starting to wilt – a quick drink often does them wonders!
Now of course some plants need more water than others. And some need water at different times of their lifecycle. We’ll talk later about how different plants might need a different approach to watering.
For now though let’s talk generally about watering.
To decide if our plants need watering we need to look at the soil – down as far as the depth of your spade. If the soil is damp then it’s unlikely you’ll need to water, but if it is dry, then watering is probably a good idea!
Don’t forget that the type of soil can trick you into thinking it might be damp – or dry! Clay soils can feel damp even when there’s no water available for your plants' roots and sandy soil can feel dry even when there is some moisture present.
So what we also need to do is take a look at the plants themselves and with that gain experience that will allow us to understand what the soil actually looks like in comparison to how well the plants are actually growing. If the plants leaves are starting to darken then that is usually a sign that they might be about to wilt – a sure sign that they could do with a drink!
So when should we get the watering can out?
Well it’s a good idea to water plants early in the morning as this will help avoid evaporation loss during the day. When the weather is warm then watering in the evening is a good idea as the dry soil will easily soak up the water and lower humidity at night will help reduce the risk of disease.
It is always better to water the garden before the soil gets really dry and drought sets in and to aim to keep the soil moisture levels as constant as possible. If left too late and if a drought has set in then a thorough watering is what’s needed. Again first thing in the morning or later in the evening is preferable so as to reduce the loss of water through evaporation. Light watering should be avoided at all costs as doing so may encourage your plants to develop roots on the surface of the soil rather than deeper ones. Plants with surface roots are more susceptible to drought.
Drainage of course is important – we want the water to get deep into the soil and to reach the roots!
Next time we’ll talk about how much water to apply and how best to do so.