Posts tagged “Shrubby cinquefoil

Strange but Interesting Potentilla

Usually when you collect a tree, you have a rough idea of the final image you wish to achieve. Other times, you just see something interesting and decide to “collect first, ask questions later”. This Potentilla fruticosa was one of the latter.

It was collected last spring and hasn’t been touched except for a couple rounds of indiscriminate hacking of long branches.

Shaggy potentilla bark hides much of the details.

After removing the bark, the embracing fused trunks with interesting movement become more clear.

Another view. This little tree has some decent natural shari on both trunks as well.

This one is going to take some more thought. I have some ideas, but nothing solid yet. For now, I will continue to let it grow, hacking it back every couple of weeks.


Tired Old Potentilla fruticosa

The potentilla that is the subject of this post was collected about 10 years ago by a friend of mine. I have admired this tree for some time, as potentilla’s of this size and drama are quite rare. When I had the opportunity to buy it for a reasonable price last year, I didn’t hesitate!

Potentilla fruiticosa yamadori

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However, this tree has some serious issues and serves to illustrate some limitations of potentilla for bonsai. In a recent post, I said that potentilla are one of my favourite species. They are certainly not perfect, however. Many people will refer to the limited longevity of potentilla. While they are hard to kill, their weedy growth habit is subject to dieback. Their biggest issue, however, is wood rot. This tree is a perfect example of the issues that arise with potentilla over time.

When designing potentilla bonsai as a deadwood species, you must be very conscious of the soft wood. It is nowhere nearly as robust as the deadwood of other deadwood species such as Thuja and Juniperus, and requires extra care. This means treating at least once a year with a penetrating wood hardener, and keeping the deadwood clean and dry. This is the product I like to use.

These techniques were not applied to this potentilla over the last decade, and as a result it has lost much of its structural integrity as a result of rot. Some of the fine jins near the base of the tree also crumbled away when I first laid hands on the tree last summer. The tree is literally falling apart. To make things worse, was planted in a very mucky organic soil mix which takes a long time to dry out.

The purpose of this spring work was mainly to take steps to minimize the advancement of the rot by doing the following:

  • Remove as much of the rotted wood as possible
  • Bareroot the tree and replace the soil with a coarse inorganic mix
  • Plant the tree more upright so that the deadwood is far away from the soil surface
  • Treat with limesulfur, then wood hardener

Crevices such as this are highly at risk of rot, especially if they are not kept clean and dry.

This organic soil mix holds far too much water. This rotted the jins that (used to) lay on the surface and also creates too much humidity for the deadwood that lies above the soil. It is worth noting, however, that the tree grows fine in this soil. Potentilla will grow well in almost anything!

The video clip below shows the extent to which the rot has compromised the structural integrity of the tree.

 

This is the new pot. It is a yamaaki pot with some signs of age. It is far from ideal, but I think it is a slight improvement on the current pot. I think this tree is ideally suited to a crescent stone, but I have not been able to find the right one yet!

After much struggling, I decided to break the pot. The unusual shape made it very hard to get the tree out and, given how fragile the tree has become, I did not want to pry on it too hard. This pot was made by the previous owner and he warned me that I might have to break it - sorry! :)

Barerooted with the hose and trimmed. You can see that the root system is strong despite the difficulties the tree has presented to the bonsai design.

The tree is so "floppy" that it had to be tied to itself in order to achieve the desired angle. This guy wire is hidden at the back of the tree and can be adjusted if needed.

Thats it for now. Much cleaning and wood preservation still needs to be done, but I think that the deadwood is much safer now than it was before.

The back of the tree is quite interesting as well. As the structure of this tree continues to deteriorate, I am sure that I will have to keep other design possibilities in mind.


Twisty Potentilla Clean Up

Potentilla fruticosa (Shrubby Cinquefoil) is one of my favorite species for shohin bonsai. In rocky northern regions, interesting specimens are easy to find which can be yanked out of the ground like turnips with a nearly 100% success rate. They are not a particularly common subject, but can still be found in bonsai gardens in most temperate regions of the Northern Hemisphere. I’ve seen amazing specimens coming out of North America, Europe, and Japan.

This is one of several small potentilla I collected last spring. In the proper soil they will quickly develop a fibrous root system and are almost always ready for rootwork the following year. Unfortunately (like junipers) collected potentilla may stubbornly hang on to a few long thick roots that can be difficult to chase back. Cutting back roots has to be done with great care because the compartmentalized nature of their growth can lead to dieback of live veins that are critical to the design of the bonsai.

I collected this tree because while crawling around in the mud I caught a glimpse of a twisting trunk hiding beyond the weeds and flakey bark. The initial clean up is one of the most important steps with collected potentilla, because you never really know what you have until you remove the bark and punky wood.

So here we are, nearly one year after collection, and I finally get to see what I brought home with me!

This shaggy mess is typical for collected potentilla. The paper-like bark hides the most interesting features of the tree.

It seems that there is some potential with this little tree, but it is impossible to tell until further cleaning is completed and the nebari is exposed.

The flakey bark peels away easily with tweezers or using your fingers. It is also necessary to scrape and dig in the many crevices of the tree, where dead bark becomes trapped and rots between the fusing stems.

Once the bark is removed, the dancing nature of the trunk becomes clear. It is also clear that this tree is the result of several stems which have fused together at the base. The cleaning process is not nearly complete. Getting all the old crap out of the crevices takes lots of time and patience, and will probably take another couple of lazy summer afternoon sessions of picking and scraping. Nevertheless, the work done here is sufficient to map out the design.

The next step for this tree will be rootwork in the next few days. If the root system does not need major operations, it will grow strongly and I should be able to cut it back hard in the late spring or early summer. Potentilla backbud profusely and reliably, but they need to be cut back quite ruthelessly. After that, the deadwood work will come. I intend to reduce the live veins to emphasize the twists in the trunk.

It is worth noting that potentilla are ridiculously hardy, and I find they are always the first species to wake up in the spring. Some of mine are already leafing out, 2 weeks earlier than normal due to the mild winter we experienced. I usually repot them when the leaves just begin to emerge, although this is definitely not the only time they can be repotted.

On to the next one!