Why We Water

One of the key aspects of plant maintenance, along with feeding and pest/disease prevention is the watering of your plants. Much like ourselves, the majority of plants need water to survive but its important to know how and when to water to get the best results from your actions and hence the benefit your plants the most.

Plants take up water through the process of Osmosis, this is where the plants thin fibrous roots which have thousands of tiny hairs on them absorb the water molecules from the surrounding soil. This can only be done when the soil is moist so hence the need to water during drier weather.

How We Water

Knowing how the plant absorbs its water, it’s now clear that to make this happen efficiently we need to water at the base of the plant where the roots are, ensuring that the soil is wet (but not too wet, we’ll come to that). Obviously, this is easy when you have plants with longer stems but even with bedding plants and ground cover it is always best to try water soil rather than the leaves of the plant. Soaking the leaves can lead to fungal infections, scorching and more rapid evaporation all of which are not beneficial to the plant.

So how do we avoid this? If the plants are in a pot, it is possible to just hold the foliage to one side whilst you water, but if they are planted in the ground, try to get the hose/watering can nozzle as close to the ground as possible as you don’t want to be crawling around on your hands and knees whilst watering. A long-handled hose fitting can be really helpful with this

How Much do we Water

This is a very common question, that unfortunately has a complicated answer. It can depend on the type of plant, where it is in its growing cycle, the soil type and the weather.

Starting with soils, a sandy or chalk soil will need more watering than a clay soil and similarly we are finding that peat free composts do not hold the water as well as their peat-based predecessors. Adding organic matter to soils can help with water retention in fine soils whilst improving drainage in more clay-based soils which is also important. 

Where the plant is in its growing cycle has a big effect on how much water is needed, a cucumber for example will need a regular supply whilst it is producing its fruit, as would most other fruits, vegetables or flowering plants as this is when they are working their hardest. A houseplant through the winter months as another example, whilst still needing some water, its activity is much reduced so would probably only need watering once a month whereas a deciduous shrub in the garden would need no watering at all in the winter months as it would be completely dormant.

The weather clearly has a big effect on whether watering is required, most plants would only need watering during dry periods, late spring/summer in a normal year or immediately after they have been planted assuming they are somewhere the rain can fall on them. Those in pots will dry out more quickly than those in the ground as the volume of soil is less and the added containment of the soil will also speed the evaporation process up, In many cases, you would need to water your pots and baskets even if it has rained, because these are also more likely to have the soil covered by foliage and flowers so much less of the water will have got to it and will simply have run off the sides of the container.

So can you water too much? In a nutshell yes. As well as water, plants still require oxygen to breath, normally this is obtained again through the roots from pockets of air in the soil, soaking the soil can remove these pockets and that will kill the plant, this is why drainage is important whether its in a pot or the garden.

Finally, to how wet do we make the soil? Again, this differs depending on whether its containers or the borders. In the border it is better to water heavily but less frequently, this ensures the water gets down to the deeper roots, encouraging root growth and making the plant more drought tolerant. In containers, its pretty much the opposite, watering to roughly a 10th of the pot size, (e.g. if it’s a 10ltr pot, give it 1 ltr of water), ideally have a saucer underneath to catch any water that runs through and also hold it so that it can drawn back up by capillary action for the plant to use. As a rough check, push your finger into the soil to about your second knuckle and if it comes back dry, you need to water, or you could try our watering worms which are ideal for showing when watering is needed.

When is the Best Time to Water

So we know why and how but when is the next question. In an ideal world, you would water first thing in the morning so that the water is available for the plant when it starts to grow in response to the light and before the sun is bright therefore reducing evaporation. As a second choice then in the evening, as it again reduces the risk of evaporation, will have water in the soil available for the plant in the morning, however, it does mean leaving the soil/plant damp over night which can encourage slugs, snails and fungal diseases.

Finally, if like us at the garden centre, you can only water during the day, obviously this is better than not watering at all but be mindful of the tips mentioned earlier about how to water, avoid water on the leaves as much as possible, be aware that a lot of the water will evaporate before it reaches into the soil and that it is not the most efficient time to do it.

What equipment to use?  

Head over to our Hose Page for more information