In a competition we ran where the giveaway was one of our Japanese chrome watering wands, we requested followers and customers to submit their top watering tips.
To make sure this valuable information did not get lost we turned it into a blog post. In no particular order the following tips are shared with our comments added for further re-enforcement.
"I recently purchased an inline water filter as well to stop my nozzle from clogging up from any debris which bypassed my downpipe filters. Handy little addition to watering system."
This is a great idea, particularly if you use water from a non-potable source. If you use municipal water there really shouldn't be such large particulates present in the water that a filter becomes necessary. However, for drinking and cooking water I have long filtered our municipal water.
"An air pump to oxygenate mature rain tank water is high beneficial to soil microbes, improving root function and natural pest immunity. It also greatly increases soil aeration."
"When I water my trees, I always make sure that at least the top layer of soil is dry (usually 1cm deep) if this is the case, I would then soak my trees with a fine spray until water comes out the drainage holes. I will then wait until all the water has drained through and soak again, I also spray the foliage of my trees as well, especially during hot days. On hot days I will water 2 times daily. I also only water my trees at specific times, either early morning (usually done in winter) and Sunset."
Such a great and valuable tip! Too many times, enthusiasts water but do not check if water runs completely through the volume of the container. Deciduous trees need to be watered a little earlier than conifers, as deciduous trees prefer slightly wetter roots. Alternatively you can allow for this by increasing the amount of water retentive material in your soil mix. I would suggest NOT to water at sunset, rather water late afternoon to allow sufficient time for the water on the foliage to dry off before nightfall. In this way fungal problems can be reduced.
"To check if soil is wet for watering, stick a small piece of dowel rod into soil, wait a few minutes. Check if it gets wet no need to water if dry water."
When you are just starting out in bonsai, knowing when to water can be a challenge. These sorts of suggestions can be helpful. You can also tell by the colour change of the soil, especially Akadama, which turns from a dark brown back to a light brown colour.
"Watering is the most important part of taking care of your bonsai. Always make sure when watering your bonsai trees, that the soil is soaked. Don't be scared to over water but NEVER under water. Never let your bonsai trees get to dry."
When I go away for any length of time and cannot personally water my bonsai collection I would rather the person who does, overwaters than underwaters. If a tree dries out it will die. That's the worst case scenario. If it only partially dries out it can lose its leaves or needles, or branches only but still barely make it. If you overwater for a short period of time this does not present a challenge, its similar to having long periods of rain. Sustained overwatering however is a problem and will produce root rot. To some degree this can be mitigated by using a well draining growing medium, but the best long term solution is to learn how to water correctly.
"Check the weather if you’re going to work water before you go if needed."
Very valuable advice. With the weather nowadays that seems to change so rapidly proceed with caution though. I would rather water before leaving than risk the chance of my trees drying out during the day while you are at work.
"I run the hosepipe with my thumb over the end for control, and often do a second watering for a good soak."
I kink the hose with my left hand to control flow, with my right hand holding the watering wand.
"You can install a simple drip irrigation system (available at most DIY stores) to drip irrigate throughout the day. And depending on the weather also spray the trees and surrounding area to increase the moisture around the trees. And if you live in a windy area like the Cape, watch the wind and water accordingly."
Personally I am not a fan at all of automatic irrigation, for a variety of reasons. However I can see the need for such systems on occasion. If you do go this route, make sure your drippers are able to provide water to the entire circumference of the root ball. Dry spots will be the demise of roots growing there.
"Don't assume your trees are getting enough water when it's raining, even if it's been pouring for a few days. The surface areas of our pots are often very small, and some trees may have large canopies that don't allow rain to reach the soil below. Always check your trees even if it's raining, they may be bone dry when the rest of your garden is soaked."
This advice cannot be overstated. I am guilty of this myself, its just so very easy to be beguiled by the rain!
"During the hot and windy summer months a drip tray filled with gravel and water and put your container filled trees on top of the gravel and give your tree that extra needed humidity. Nothing wrong with a good misting of trees leaves also during the hot days"
Nothing wrong with this advice, although personally I don't think the evaporating humidity will be significant, especially if there is a breeze. Rather use something like these foggers if possible to increase humidity. However partially burying your smaller sized trees into the soaked gravel has merit as water can be absorbed from this into the small bonsai container.
"Treat yourself to a fine-spray watering system (on a timer, of course), then sit back, with a chilled beverage of choice and admire you hard work."
Ha ha ha! This bonsai enthusiast is definitely onto something here. Be careful when using anything automated, too many trees have died as a result of a timer which did not run. Also, after installing your sprayers, test them on a windy day to see if they do in fact water your trees or whether the water doesn't just blow away.
"Water is very important to all living things especially trees because without them we will not be able to breathe. water my trees twice a day it gets hot in the Northern cape I soak my trees once a week a specially my big trees to make sure that they are nice and wet."
Frequency of watering through the seasons is very important for you to work out. Correct watering is not easy and takes many years to master.
"On hot days, just wet everything if your trees are on a balcony like mine are. The added humidity will provide some respite from the South African sun."
You can provide your trees with some very temporary relief in this manner but in the long term you need to consider where you place your trees carefully. If you position them in a space which is highly reflective and all cement, stone or brick your trees might not grow very healthily. You could break this by adding wall gardens and other pot plants, painting a colour other than white, installing a water feature or more. If possible install foggers like these and run them frequently throughout the day using a timer.
"With this heatwave we're experiencing, water your trees in the morning and keep them in the shade to retain moisture as long as possible."
Shadecloth is a great way to protect your trees, especially the more tender species from the harshest of the midday sun. However don't go too heavy on the shade factor or you will find the internodes on your trees as well as the leaves getting much larger. My person preference is 80% white which gives a 40% shade factor and does not reduce any colour spectrum in the light received by the plants.
Don't switch up your watering routine often unless there really is a need - the tree becomes accustomed to its regular watering times - assuming the schedule is appropriate, and the tree is responding well.
I water at random times, when my trees need to be watered. I doubt there is little evidence to support trees like a routine, however getting into a routine will help YOU to not forget to water.
"When your trees are dry you can dunk them in a bucket of water and add some organic fertilizer . Dunking helps to get rid of the air pockets in your soil. And the fertilizer just makes it much easier to fertilize a lot of trees all at once."
The first part is a great suggestion! If you find you left your tree too long before watering again it is beneficial if the tree is physically not too big, to dunk it in some water. If you then leave it in the water for around 30 minutes it will become thoroughly soaked and you can go back to normal watering again. Adding fertilizer is a good idea too, however I would not suggest this method of watering/fertilizing in the long term. If any of your trees have any pests or diseases on them you will aid their dispersal by passing all of them through the same container to water or fertilize them. Each tree should ideally be watered and fertilized individually.
"Living in the Kalahari it helps to use some extra peat moss for water retention. But if you do use peat mixes, make sure not to let the soil mix dry out completely as it will become hydrophobic and difficult to water thoroughly. If that happens it helps to soak the whole pot in a bucket of water until the medium is completely saturated."
Adding organics for additional water retention is plausible, however as the poster suggests, it can dry out and become hydrophobic, but it also compacts starving your tree's roots of much needed oxygen. Sifting your organic material and removing the fines will reduce this phenomenon. For additional water retention you can use more akadama in your mix, or use a long fibred peat (not coco peat) or fine, sifted bark.
Never water your trees on a schedule as the water requirements can change depending on the environment around the tree such as weather as well as the specific water usage rates that differ from species to species.
This is fantastic advice! Even working on your trees, such as defoliating a tree will dramatically alter how much water is needed by that specific tree. Make allowances for this.
"Another factor to take into consideration is that of the soil mixture your bonsai is in, as certain mediums or mixtures of mediums water retention rates differ."
This is very true! Additionally, if you purchase a tree its best to repot it as soon as you can so that it is in a soil mix which you are familiar with, which is also the same as the rest of your trees. This will make watering easier for you.
"However, when one does water be sure to cover all parts of the medium and ensure that water does come through the drainage holes in access as this will guarantee that the bonsai is being watered adequately. And finally, do not water your bonsai with a spray bottle as that does not allow for enough water to penetrate the root system but rather only wets the top of your growing medium leaving a false sense of adequate watering."
Watering till water runs through the drainage holes has been mentioned before but I left this tip in as I liked the reference to the spray bottle. The poster is 100% spot on.
"When you water with a hose and it was laying in the sun, let it run a bit before watering - the first bit of water is super-hot!"
Fantastic suggestion, and one I have formed a habit of performing every time I water.
"Adjust your soils mixes to suit the tree’s needs. That way, when you have lots of trees as we all invariably do), they can ALL be watered every day, come rain, wind, or shine. I found that's the way to "protect" the plants from over/under watering by gardeners, house sitters etc"
I have followed this advice for some time and agree that its a great tip. Its the most manageable way for me to water my trees well, and at the same time.
"When watering your bonsais, use either rainwater or filtered water. Do not use tap water because tap water contains additional chemicals that are not good for bonsais."
I think its a great idea to test your water and see if its suitable to water your bonsai with. Potable water is usually going to be fine, but on the rare occasion it is not consult a water treatment company about how to improve it. Rainwater is not a sustainable solution year round unless you live in an area of high annual rainfall.
"We live in a hot windy area and find it's best to water at least every second day in summer, moss helps to stop the soil drying out too much too fast."
Frequency of watering depends on many factors, which is why I refer to watering as an art. It can only be learnt by experience. Moss, or top dressing made from chopped sphagnum moss can be a useful ally in preventing the top surface of your container and therefore the surface rotos from drying out.