Not long after my deciduous bonsai leaf out, I start thinking about when the perfect time would be to prune and partially defoliate them. In general, the more dense the branches, the earlier in the season I do the work.

Once deciduous trees reach a certain density, spring growth on the outside branches shades out interior growth. In order to maintain this growth, I shorten shoots that have extended beyond the desired silhouette and remove a bit more than half of the remaining foliage.

Depending on the species, I might do a few other tasks. On Korean hornbeam, for example, I make sure to remove any shoots that have sprouted directly from the trunk. These won’t ever be part of the tree’s design, so the sooner I can remove them, the better.

Korean hornbeam in spring

After pruning and partially defoliating

Instead of partially defoliating dwarf wisteria, I shorten new shoots and reduce the size of the leaves by cutting back to the first four leaflets (thanks to Mike for doing the work this year!).

Dwarf wisteria

After pruning and cutting the leaves

Because zelkova grow so quickly, they offer several opportunities to improve the branch structure throughout the growing season. When pruning to the silhouette, I make sure to keep about 1/4″ of new growth (usually two new leaves) as this is the primary process by which we can improve the branch density.

Zelkova

After pruning and removing excess foliage

I returned all of these trees to their usual spots in the garden, now under shade cloth at this time of year. If new shoots appear later in the growing season, I’ll shorten them as I did above but skip the partial defoliation and leaf cutting on the hornbeam and wisteria. The zelkova, however, may need pruning and partial defoliating several more times before fall.

News & Updates

[Northern California Bonsai Show]

• The Bay Area Satsuki Aikokai and Yamato Bonsai Kai will be hosting their annual joint exhibit this weekend, May 17-18, at the Lakeside Garden Center in Oakland, California. Hours are 10am – 5pm Saturday and 10am – 3:45pm Sunday. See details at the GSBF website.

[Seattle area workshop]

• If you’re in the Seattle area, I’ll be leading a workshop focusing on long-term bonsai development on Sunday, June 1st. Bring trees of any species to learn the next steps of developing bonsai in early steps of development (how to create trees with good root bases), middle stages (how to create an attractive trunk) and initial refinement stages (how to establish primary branches). Learn more and sign up at the Bonsai Northwest website.

[Southern California Exhibition]

• If you’re thinking about submitting trees to this year’s Naka Memorial Exhibition (August 16-17 in Los Angeles), the deadline is June 1st. Julian Tsai and Ryan Pitts are chairing the event and looking to present the best trees possible. If you’d like to participate or learn how to submit your trees for consideration, check out the John Naka Memorial Exhibition website.

[Pine workshops]

• I’ll be hosting pine decandling workshops on June 14 from 9am – 1pm and from 2pm – 6pm. Bring any number of pines at any stage of development that need decandling or wiring. As the focus will be on decandling, the workshop is best suited for black and red pine bonsai. Sign up at the Bonsai Tonight Online Store.