Ginkgo biloba

Yew and Ginkgo Spring Images

Taxus cuspidata 'nana', 10 years from nursery stock. This year it will be thinned and wired again.

Taxus cuspidata ‘nana’, 10 years from nursery stock. This year it will be thinned and wired again.

Ginkgo biloba "chi-chi", 7 years in development from imported raw material. Probably started as an air layer in Japan.

Ginkgo biloba ‘chi-chi’, 7 years in development from imported raw material. Probably started as an air layer in Japan.

 


Bonsai is (Usually) Not a Rescue Mission

The phrase “bonsai is not a rescue mission” is sometimes used to discourage eager bonsai enthusiasts from trying to make a bonsai from every plant they find. Instead, we should focus on the best material we can possibly get our hands on, thus increasing our chances of making something we can be proud of.

Sometimes, however, bonsai really is a rescue mission. Story time!

Last August I responded to an online ad where someone was selling their collection. Not knowing what to expect from the vague description and two blurry pictures of some tropicals, I arrived surprised to see a very old and once impressive bonsai collection in its final death throes. This elderly gentleman had been doing bonsai quietly in his backyard for 30-40 years, away from the clubs and shows, and now was in the predicament of having to sell everything due to failing health.

He had (understandably) put off selling them for years, but in those last few years the trees suffered greatly. To make matters worse, everything was planted in pretty much pure topsoil and was weak to begin with, therefore many were unable to handle the stresses of erratic watering.

Some of the tougher species were still hanging in there, but other more finicky ones like this impressive Japanese white pine had no chance.

Imported Japanese white pine.

Imported Japanese white pine.

After much haggling I went home with two larches, a ginkgo, and a Japanese maple – three very tough species that had managed to survive but were now in serious need of rehabilitation. This was August 2014 and some of the trees were already showing fall colours- A sign of definite stress.

I’m happy to report that all four trees survived the winter and were completely barerooted and repotted this spring. They seem to be doing well and I anticipate that they will have recovered their strength by the end of this growing season.


Ginkgo Winter Image

Ginkgo biloba “Chi-chi”, originally from Japan as an air layer from a specialist Ginkgo nursery.

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Do Ginkgo Wounds Heal?

I’ve heard and read several times that “Ginkgo scars never heal”. I’ve also heard and read “Ginkgo scars heal, but extremely slowly”. My experience with my one Ginkgo leads me to believe that the latter is true. Or wait. Maybe both are true?

My little Ginkgo has lots of old dime-sized wounds that were never really cleaned up. Last July I ground two down with a dremel, exposed the cambium, and packed them with the clay-type wound sealant.

July 2012. Terrible picture, but hopefully you can see the cleaned up wounds. Before, they looked like the other old wounds that are all over the trunk.

July 2012. Terrible picture, but hopefully you can see the cleaned up wounds. Before, they looked like the other old wounds that are all over the trunk.

The other day I removed the cut paste to have a look. One of them (smaller one on the top) has definitely produced a significant callus. For such a small wound, the callus is moving very slowly. A maple probably would have easily healed over this wound by now. The other larger one at the bottom doesn’t seem to have done much at all. I can’t really explain what the difference is. Maybe something to do with localized sap flow.

Smaller one beginning to callus over. Tweezers for scale.

Smaller one beginning to callus over. Tweezers for scale.

This is the larger one. A tiny callus appears to have formed around the edges, but it hasn't really moved at all.

This is the larger one. A tiny callus appears to have formed around the edges, but it hasn’t really moved at all.

I will continue to re-wound these calluses to keep it moving, and will clean up the rest of the wounds on the tree bit by bit, hoping that they respond well. Either way, the end result will look better than it does now.

 


Ginkgo 2013 vs 2009

Looking at older pictures, I’ve started to notice how much this tree has been swelling at the base (left side), mainly due to sucker shoots which I constantly remove during the growing season. I don’t think there’s much I can do about it, so hopefully it doesn’t become too grotesque.

April 2013

April 2013

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Ginkgo-Oct-24-09

October 2009

 

 


Another Season Done

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Overwintering Bonsai in the Toronto Area USDA Zone 5-6

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I’ve received quite a few emails from people asking about overwintering hardy trees outdoors. While there is lots of good information out there on the internet, most of it is region specific. What applies in England, Japan, or North Carolina does not apply in Toronto. With that in mind, this information is specific to zone 5-6 and is for people who have no special facilities (heated garage, polyhouses, etc.).

Reiner Goebel of rgbonsai.com has a good article about overwintering trees in the Toronto area. Have a read here. What I do is very similar.

  • Use tough species to make life simple. Semi-hardy species (Trident maples etc.) require more attentive care in this climate. My collection consists of Eastern White Cedar, Larch, Juniper, Yew, Siberian Elm, Potentilla, Ginkgo, and  few others. All fully hardy.
  • Don’t be afraid to leave them on the bench through a few late autumn frosts. They can take it. I usually put mine away in late October or early November. If the ground is frozen, you’ve waited too long 🙂
  • Bury the pots in the ground in your garden and water everything really well. This insulates the roots. The risk is not the rootball freezing. It can and should freeze solid. The tree will be fine. The risk is frequent freeze-thaw cycles. This is why unusually warm winters are more of a concern to us northern bonsai growers than unusually cold ones. Burying the pot helps ensure that once the rootball freezes, it will stay frozen until around March, even if there are some freakishly warm days in January (it happens). If your tree is in a massive training box but is a hardy species, just sit it on the ground and mulch around it. Just having contact with the ground will help buffer the rootball temperatures.
  • Snow is your friend. As soon as fluffy snow hits the ground, shovel it onto your trees (don’t shovel on heavy wet snow!). Sure, three feet of snow can bend branches but I feel most comfortable when my trees are buried in snow all winter. This protects from -20 degree air temperatures and drying winds. But when the snow starts to melt, brush it away as this heavy slushy mess can really cause damage to branches and fine ramification.
  • Try and winter them in a shady spot in the garden protected from the wind (i.e. a north facing corner). This provides a bit of insurance against wind and sun if it is a snow-less winter (like the infamous winter of 2011). It also helps keep the tree dormant as far into the spring as possible. This is important. If your trees break dormancy too early, the tender new growth will be exposed to the unpredictable early spring weather.
  • Rabbit-proof your garden as best as possible. When rabbits get hungry in the winter, bonsai bark apparently looks quite appetizing. Even  a couple of exploratory nibbles can ruin the image of a tree. Try to board up any gaps under the fence.
  • If you have the energy, fence in your trees with hardware cloth to provide further protection from pests. Burying the fence a couple of inches provides me some reassurance against mice, although if mice want to get anywhere bad enough, they will find a way.
  • Don’t worry about watering! If you put them away late enough, they should not need any water the entire winter.
  • Again, keep them dormant as long as possible. Don’t take them out of the ground at the first sign of spring in March. You know that in our part of the world it is not impossible to have freezing nights in May, and these spring freezes can kill off tender new deciduous growth.

This approach has worked well for me for 8 seasons. There are many ways to do it, but I find this to be the simplest and most foolproof approach. It takes some time to prep the trees for winter, but once they are in the ground you can literally forget about them, sit back, and wait for repotting season to come! Unfortunately, since the trees are frozen solid in the ground, you cannot really work on them in the heart of winter.


Pruning Ginkgo to Develop Ramification

Ginkgo have a bad reputation for developing ramification, but that doesn’t mean they don’t ramify at all – they just need some encouragement! Unlike other deciduous species like Maple or Elm that will develop some ramification even with improper cutting techniques, Ginkgo will barely ramify at if they are not cut properly. Still, even in the best of cases, Ginkgo ramification cannot hold a candle to that of maples… but that is just the character of the tree. They are still a great species to work on.

This post outlines the pruning techniques I use on my Ginkgo in USDA zone 6.

The first step is making sure the tree is growing strong. This tree was repotted in March but has grown better than expected.

I don’t cut my ginkgo until it is showing very strong shoots like this (about five pairs of leaves). This gives the tree some time to build up strength. I find that if I cut it too early, the tree doesn’t respond well.

Here is a typical gingko branch. The buds circled in red are backbuds. Ginkgo backbuds very well, and most buds open up in the spring. However, the problem with Ginkgo is that it is hard to get these backbuds to extend into twigs. Usually only the end of the branch (circled in blue) will extend during the growing season and the backbuds will just form winter buds. Therefore, you need to cut back the tip of the branch to one pair of leaves to redirect some strength to the backbuds. This is a rather weak branch, so the side buds may not even start to extend until the process is repeated next year. Again, I find that if the tree is allowed to gain some strength in the spring, you will have much better luck getting the backbuds to extend.

Here is a stronger branch after cutting the tips back. This branch is strong enough that I would expect some of the back buds to extend.

Strong apical nodes that have not yet extended may have 3-5 leaves instead of the usual 2. Cut off some leaves to leave just a pair. This weakens the outside of the tree and allows more light into the inside. This is especially important for the top of the tree since Ginkgo are very apically dominant.

After cutting. I will continue to fertilize the tree heavily and the process may be repeated again in the summer. Further leaf-thinning may occur throughout the season.

Really, the pruning techniques for Ginkgo are very similar for most deciduous trees. The development is just much slower and the end result less ramified. However, I’ve found that by using the above strategy, I can increase the twigginess of the tree by about 50-75% each season.


Ginkgo wire removed

This is the first spring where I am having trouble keeping up with the needed work on my trees. I am planning on doing some (more) culling on my collection soon, but much of that depends on the survival rate of my newly collected yamadori. I don’t have a huge collection (40-50 trees), but giving every tree the attention they need really takes a lot of time.

In the meantime, I am busy as hell. A friend was nice enough to remove the wire from my Ginkgo  for me 🙂 As a side note, this guy also has an amazing collection of fine mame and shohin sized pots and is always selling/buying. If you are looking for nice small pots, check out his website: Mame & Shohin Bonsai Pots.

As for the Ginkgo, many of the branches sprang back once the wire was removed. Kind of expected. Ginkgo is tough to wire because it scars so easily. Last year I wired it in late October and took off the wire yesterday (April 30). The branches seemed to have set better than in the past where I have wired it in March and had to take the wire off by early June.

I still haven't decided on a front for this tree. I think this side is more attractive, but the apex leans slightly back (it was not designed as the intended front by previous owners).

I think this is the original front of the tree, but I don't like the two symmetrical lumps about 1/3rd up the tree. They never used to bother me, but then my friend's wife pointed out that they look like bull testicles. Now that's all I see!