Continuing to Repot - with Care

     A little over a month ago I wrote about the dilemma facing many of us in this part of the USA: with our weather patterns so weird, should we repot in response the normal indicators (swelling buds, etc) or wait - maybe even forego repotting for a year? (If you want to refresh your memory, click here, then come back.)

As I indicated in that post, I decided to proceed with repotting but take some extra precautions.

Two trees I've recently worked on are hybrid yews, Taxus x media 'Densiformis.' I acquired them both almost two years ago from the "Clearance" section of a local DIY's garden center. Both had been allowed to dry out too far and were in serious distress; their survival was uncertain for a number of months. I babied them with frequent mistings and extra attention all last season, and I'm thankful to say that it paid off. Both trees came out of dormancy this spring in vigorous health and breaking new buds all over the place!

Unfortunately, by the time I could get to their repotting, buds on both trees weren't just breaking, but bursting. As many readers will know, you take a risk with yews if you repot them after the buds are already opening. So I handled the roots as gently as possible and did almost no root pruning on either.

Since these yews came from a general-purpose garden center, it was anyone's guess how much of the trunk of each was buried, where the nebaris would be found, and how they would be angled. That's just something you deal with when you buy from a general purpose source; I actually often enjoy the added bit of challenge.

Fortunately, the first one was not especially root bound. The angle of the nebari (once I found it) was such that the tree will most likely end up a semi-cascade, tho it will be several years before it is ready for creating styling.

Taxus x media 'Densifomis' B190, April 24; cleaned up and ready for repotting.

Some live roots ended up sticking into the air after I got the nebari leveled - they'd all been growing at a different angle for several years, after all! There were enough such that - again, wanting to save as many roots as possible - I covered them with sphagnum to keep them moist while the tree adjusts. I also mulched the rest of the surface of the substrate with sphagnum.

Please forgive the quality of the next two pictures. I'm afraid I don't have any other "after" photos.

Probable front, altho that could change. The lower trunk looks best from this side.

Probable back.

The second tree was rootbound, and badly; the rootball was full of small roots that had been killed by overcrowding. Most of the live and viable roots were near the bottom of the rootball. Again, I couldn't afford to lose any live roots if I could help it, so reduction of the roots' depth will be done in stages over several repottings.

Taxus x media 'Densiformis' B191, May 11. You can see the new shoots opening.

With the rootball cleaned as much as I dared under the circumstances. 

A closer look at the root mass. That's my left hand at the side of the picture.

You can see in the last two pictures that most of the original trunk was buried; what look like multiple trunks in my first picture of this tree are actually the primary branches. But you can also see that there is a significant reverse taper just below the point where the branches emerge. Because of that, and because I think the design idea will work, I plan to make this yew a 5-trunk clump.

To develop a new nebari, I punched a series of wounds all the way around the trunk, one-half inch to one inch below where the primary branches initiate. (A few of them show as light spots a little above the soil line, in the picture below.) Rooting hormone was applied to the wounds, and that area was packed with sphagnum as the last stage in the repotting.

With substrate filled in to just below the circle of wounds. Rather than run the tie-downs over the area
where I want to see a new nebari, I looped them around branch bases. This is the most likely front.

The picture doesn't show it, but the sphagnum is packed higher right around the trunk, covering the hormone-treated wounds.
I finished this job in the rain, which is why everything - including me - was wet!
(I have no idea what caused the lighter area on the picture's right.)

The wound-then-apply-rooting-hormone-and-pack-with-sphagnum technique is one that works with many species, especially many tropicals. One of the characteristics of 'Densiformis' is an unusual readiness to break new buds, be they foliage buds or root initiations, so I think there's good reason to expect the approach to work on this tree.

(That readiness is another reason I was willing to take a chance on repotting these two yews after the optimum window was well past.)

This tree is a long-term project; I expect it to take at least five years to develop a new nebari to the point where it can support the tree on its own. But if I can do it justice, I think this yew will turn out to be a bonsai "not without merit."

:-)  :-)  :-)