“I used to have a bonsai but it died!”
I have heard this time and time again and there is usually a similar reason. Whilst it may seem great to bring a tree into the house and display it, it is not the usual habitat for it and it will likely suffer unless of course the Bonsai comes from a warm climate, in which case treat it like a house plant if you so wish…for displaying inside that is, but remember plenty of light.
In the dormant season (varies on location) warming up a deciduous tree (one that looses leaves in the winter) by bringing it indoors is a big no-no. If the species is somewhat delicate (not fully frost hardy) over winter it in a green house or poly-tunnel, but watch the watering. I over winter my Satsuki (pr ‘Satski’) azaleas but just enough to avoid heavy freezing and frosts. Before I did this, I lost several superb Satsuki’s. Since over wintering them…not a problem at all.
In a pot that has a good quality soil which is free draining you can generally water it as much as you like. Make certain the water comes out of the drain holes underneath the pot. Some species such as a Willow, I leave in a tray of standing water because I simply cannot keep up on the watering demands of a Willow. Pines on the other hand are used to dryer conditions and my larger varieties are watered generally every third day, although that is not a guide for all Pines, it just works for mine because they are used to it.
Another consideration is, start watering heavy in early Spring and your tree will look for it all season long. Take it easy to start with, and the tree will not look for so much.
Over watering then, how does it happen? No one answer really, trees that I have seen over the years that have been classified as over watered usually have a reason. Lifting the tree from the pot with a dense group of roots running round and round eventually make any soil so tight that water sits. Don’t leave re-potting so long on smaller trees. You can get away with it on larger trees. One of my White Pines has not been re-potted for almost eight years, yet it is as happy and health as can be. A large Deshojo Maple needs re-potting every year, it grows roots like they have gone out of fashion.
Under watering? What then are the tell-tale signs? err, the tree dies? wilting new growth is a great way to tell, my Hawthorn both Japanese and English, the Firethorn, Crab apples soon wilt if on the dry side and will not thank you for it. Again in the growing season you will struggle to over water these species. Pines on the other hand will reward you with great big long needles which is not helpful when spending the previous four years on a reduction of needle size programme.
Pests and fungal infections?
Way too much to go into in this brief entry but suffice it to say they have been known to kill trees a few times so watch carefully and treat with a recommended product. I tend to use Provado for white, black & green fly, it has proved very successful as a systemic treatment. (Systemic means when sprayed on the leaves it is absorbed by them into the tree to fight off over a period of time. Often 6-8 weeks although it does vary.)
My Dog urinates on my Bonsai and they die?
Well for goodness sake pick them up of the ground and stick it on a display stand, out of harms way and it is better for viewing purposes. (Yes a few times I have heard that one).
My friend said he would water while I was on holiday and he said he forgot and they died?
Find another friend and ditch that one. Simple really.
I’ll add to this entry but having just had a call from a Bonsai owner who thinks several trees have died and wanted to know why; my guess was the long and hard winter. Even hardy trees have limits so wrap em in Hessian (the pots that is) bubble wrap. Putting the tree into the ground complete with the pot is fine and can be quite helpful when that cold. Personally that is not one I have ever done but if going away and you have no-one to water for you it can make a tree quite safe for up to a week or so in a shady spot buried in earth. I’ll know more when I see the trees later today.