Perhaps you went on vacation. Or maybe you just forgot to water, for a week. You might be wondering how to save a dried out bonsai tree. You know I’m talking about you if your bonsai is now more brown than green, and has seen better days. If that’s the case, your tree is in need of emergency care.
The real question I hear is: Is the tree completely dead, somewhat dead, not dead at all just traumatized or wintering and looks dead, or is not dead at all, just isn’t at it’s best. It can be far from obvious which of these things is going on with a bonsai or pre-bonsai.
“I’m Not Dead Yet”
Just as full sized trees and shrubs loose their leaves in fall and winter, so too do bonsai. Regardless of your climate or location, you might start with an internet search to see if the type of bonsai tree in question looses it’s leaves (is it a Juniper? Azalea? Pine? Fukien tea?). The easiest first question is comparing it to other full sized trees. If you have a maple bonsai, and full sized maples around you are loosing their leaves, your maple bonsai should loose its leaves too. Trees can also sometimes loose their leaves if stressed, such as if you did major trimming or rewiring work.
If your tree isn’t wintering or stressed the question is if it’s fully dead or partially dead.
Break or Cut a Branch
One method for determining if a tree is dead is to cut off a branch. If the branch snaps and is brown throughout, it’s dead. If its white or light green inside and springy it’s alive inside. You may not though want to cut off a branch to know if your tree is dead. Also you might check a branch that’s dead but have another part of the tree that’s alive.
Consider instead the scratch test. Scratch the trunk with something sharp, like the point of a bonsai shear or yard clippers (something clean though, there’s no point in trying to save a sick tree by infecting it by gouging it with dirty instruments). If you hit green your tree is alive.
Just Keep Watering
Last, it’s also not necessarily a great way to go but you can always keep watering and watching through the winter and just wait and see if it comes back. This will probably earn me criticism but I’ve thought I lost a small Fukien tea which lost all it’s leaves after I stressed it with work, and it came back after several months, twice. I was hesitant to be too aggressive with scratch testing as it was small and thin and hitting it with periodic watering wasn’t any extra effort.
How to Save a Dried Out Bonsai Tree
If your tree is dead there isn’t anything you can do to save it. You can always try the rehydrating methods to see if part of the tree is not completely dead, but how much effort you want to put in is entirely up to you and your tree.
Water (Bottom Up)
If it’s alive, you want to start by watering bottom up. Put the tree in a bucket or bath of water that’s slightly larger than the pot. Have the water at room temperature. Fill the basin up with water almost to the rim, or over the rim of the bonsai pot. If the bonsai is completely submerged, wait until it stops bubbling. If you stop short of the rim of the bonsai let it sit for some time.
Bonsai that are severely dry will take more time for water to fully penetrate all the areas of the soil mix. Water will need to work it’s way to the core of the root ball, and some materials commonly used in bonsai may take time to absorb to their maximum (think how water can sometimes slide right off the top of a completely dry sponge. You have to wet it and let the water penetrate the sponge before it will take in more water).
Remove the bonsai from the water bath. Set it somewhere to thoroughly drain excess water. (See my article How to Water Your Bonsai, the section on bottom watering).
Next, your tree would be considered sick, so it will need babying until it returns to full health. It may need watering more frequently for the first week or so as it returns to full health. Be vigilant about its water needs and take extra care to water when necessary, not on a schedule.
Place outdoor bonsai in partial shade, out of full sunlight, for a minimum of several days. Keep it also out of drafts inside or strong air currents outside which are drying for bonsai. If inside, consider using a humidity tray or grouping it with other house plants (they don’t have to be bonsai).
Don’t overcompensate by keeping the bonsai constantly wet. Being well after being dried out does not mean being kept wet. It’s having the appropriate level of watering and moisture.
Not all severely dry bonsai can be saved, but following the above steps make for a good attempt.
After treating you bonsai, consider how the tree got dried out in the first place. Some simple steps now can help prevent it from drying out again in the future.
- For indoor bonsai – Keep an eye out for the overall humidity of the home, and watch any drafts or use of fans in the room
- For outside bonsai – Keep an eye on being placed in the path of wind or breezes, how dry the temperatures are, and how much sun the plant is receiving
Drying out could also be the culprit of your behavior rather than environmental factors. Consider using a calendar reminder at work, a daily timer at home, or find someone else to bonsai baby-sit for the next time you go on vacation.