I’ve been thinking about water more than normal recently, on account of the lack of it falling from the sky. We over here tend to take it rather for granted, but just a little too much or too little and it occupies the mind quite a bit. Me and Jude seem to have had hosepipes and watering cans welded to our hands for months now. The cycle of watering in the morning and then again in the evening has become automatic. The problem with this is, as a bonsai grower, you shouldn’t really water to a routine. Lots of factors affect how often you need to water.
- Bigger bonsai trees dry out less quickly than smaller ones.
- Certain species of bonsai tree require less water than others. Giving the pines too much water for example, doesn’t really bother them but if you overdo it you’ll end up with long needles.
- The soil mixes that you use dry out at different rates. Humus (brown soil stuff) rich mixes hold a lot of water. More free-draining mixes dry out more quickly. Smaller particle sizes tend to dry out less quickly than larger particles.
- Trees which are moving towards being pot-bound dry out more quickly, as the amount of root in the pot has increased – soil holds water, so if there is less soil and more root, there is less water retention.
- Some trees are less fussy.
So, it isn’t really a great idea to just to lump water on everything twice a day. I and lots of other bonsai growers tend to be over-waterers. Finding the balance is key. Basic advice is to touch the soil surface and if it is starting to feel dry, then it’s time to water. When you do water, soak. Soak the soil and the rest of the bonsai, trunk, branches and leaves. If you are watering with a hosepipe, angle it up a bit and water the underside of the leaves too, it gets rid of bugs. It’s often surprising how much water it takes to fully get all of the soil wet, so it’s also wise to go over your bonsais twice. After you’ve properly watered, don’t do it again until necessary.
Tap water versus rainwater? At our place we use rainwater most of the year and have a couple of big tanks to collect it off the greenhouse roofs. In hot summer we go to tap water and watering with cans isn’t practical given the volume of trees that we have. We’ve got a filter on the tap water, which gets rid of some of the nasties in the tap water. I do think rainwater is best. The PH is better for the trees. If you live in a hard water area, I’d recommend catching rainwater. Generally speaking, trees prefer slightly acidic soil, so pouring on alkaline water gradually changes the chemistry of the soil away from the trees preferred PH. This can be balanced by using an ericaceous fertilier once in a while.
Growers of the smallest bonsai, Mame and Shohin sizes, tend to have the least fun in hot weather, as the little pots dry out the quickest. The smaller the bonsai, the more hard work it is to look after it in the heat. Now if you’re an experienced bonsai grower, then that’s fine, it’s up to you. The problem is that lots of first time bonsai growers say to themselves “I’ll just get a little one and see how it goes.” Then, they get a small bonsai in a little pot. Hard work.
Anyway, I’m sat in the garden typing away and I think it’s just about to rain. Might have to duck inside with the laptop in a min. If it’s going to rain, it needs to throw it down for an hour. Little piddly showers won’t do it as far as the trees are concerned. The leaf canopies acts like an umbrella. I often joke with people in the shop than bonsai trees like nothing more than a dull, damp, grey day. Because we spend so much time with the trees, I can physically see then different a day of rain makes in summer, they just look greener and happier. The roots, trunk and branches are like pumps at end of the day, and the trees have to work harder in hot weather. You can make life easier for your bonsais in hot weather by keeping them well-pruned. Bonsai trees try to grow more foliage than they can sustain, the idea being that wild trees expect to have leaves eaten and branches that get broken. Look at big trees and you’ll often see dead branches which have been overtaken by branches growing above them.
Yep, definitely raining. Better go. Day off today. Typical…