Watering is a very interesting topic. I read up a lot on this and watched a few videos at the end of last year as we experienced a drought that took the Western Cape by surprise. I thought it would help if I shared what I learnt during this period. This is just a guideline but at the end of this blog you will see that you have been doing it wrong. I know that is a bit of a harsh statement to make as I do not know how you water and how often you water.
Let’s jump straight into it. Why do you water your tree? No really think about this why are you watering your tree? Well the most obvious answer is that the tree needs water. That is correct, but what happens in the pot or container? It took me a while to understand this. So I will put this in simple terms for you. When you are watering the tree the water fills the small gaps in between the soil mixture and the access water runs out the bottom of the container. After the access water has ran out fresh oxygen then enters the container from the bottom. The tree will then during the day use the water in the soil mixture as it needs it. The more water gets used the more oxygen then fills the gaps left after the water is used.
Another important thing to keep in mind is to water the trees’ foliage. Dust and other particles build up on the leaves or needles. This build up is the perfect breading ground for pests and insects. Not only that but they put strain on the tree. How you might ask. The build up of dust makes it hard for the tree to breath. The tree catches the sunlight via it leaves and this is used during the process called photosynthesis to create fuel that the tree needs to survive. This process is important and needs to be understood. As I originally thought that, if I water the tree now it takes up all the water I give it. I would then water all the plants and come back and water them from where I started once more. I know that does not make any sense now.
So how does the tree use the water. In my own words: The tree uses the water through out the day. The more sun the tree receives the more water it uses. There are other factors that also reduces the amount of water available to the tree. These factors include heat, wind and the water retention of the soil mixture the tree is planted in. The first two of these factors are natural occurrences and we can not control them but we can manage the effect that they might have on the environment around the tree by using shading nets and humidity trays. The soil mixture we plant our trees in we can adapt to our regional climate.
Ok… Now what? How does this all help you water your trees? Here are a few things that I found helped me:
- Water the trees regularly. Once in winter and up to three times in summer. It’s important that you get the amounts and intervals right as too little water can kill off small feeder roots by drying them out and the tree needed the feeder roots to take up the nutrients in the soil mixture. Too much water leads to root rot.
- Water by hand at less once a day so that you can look at the trees.
- You do not need to water all your trees every time you water. Water all of them in the morning and only water the trees that needs to be watered later during the day.
- Do not water to late during the day. If you water to late your tree will stand in water through the night.
- During the summer you can dip you trees in water once a week to make sure that all the roots get watered. Sometimes the roots at the base of the tree does not get any water.
- For trees in sallow trays or on slabs. Use a sprayer to water these trees as it will take longer for the water to run out of the bottom of the container this way and allows for the soil to soak up more of the water.
Here are a few trees that have in different types of soil mixtures:
This is a group planting on a slab. I used peat mos to build a wall and filled the rest of the slab with a free draining soil mixture.
This tree below is planted in a very dense soil mixture. It was a bonsai soil mix I bought from a nursery. Work well the first year. Now in year two the soil is compact and dries out fast. So I water the tree more often then the other trees. I will replant this tree in better soil next time.
This is the same soil mixture as the tree above this. In winter this works well, but during the growing season the tree needs regular watering. If the soil mixture is dry it takes a few “waterings” to get the mixture damp all the way through.
This tree I will repot. There is more root than soil. It’s a ficus so no worries here.
The tree in photo below is planted in a soil mixture that I mixed myself and it works best for my region. When I repot I only use this mixture.
In closing I would like to encourage you to get the following right to water your trees properly but also so you do not waste water. Get to know your trees and their needs. Try a few of the points mentioned above and see what works for you. Work out a watering plan that works for your trees and fits with in your daily routine. Try and control the environment around your trees as much as you can.
Here is a sneak peak off what is to come later this week:
I will be trimming back these trees later in the week. Watch this space.
That’s it for today. If you have any comments please feel free to leave them in the section below.