By RSBG Horticulturist and Assistant Curator Will Clausen
Gardens are living museums and ever changing. Those basic truths, though occasionally frustrating, are a big part of the fun of being a gardener. As 2025 wraps up, I am reflecting on some of the garden projects we completed this year and thinking about things we plan to do this winter.
Rhododendron species in subsection Taliensia are somewhat tricky for us to grow, but we seem to have found a new spot in the garden that is well suited to their needs and have successfully added plants there over the past few years. This area, just south of the Gazebo, had been neglected and inaccessible to visitors for many years. We finally opened it up by creating a new trail that winds through and connects the Upper Alpine Garden to the Upper Magnolia Plateau.
We planted some old favorites like Rhododendron elegantulum and bureavii alongside some newer and exciting Taliensia that will eventually fill the area.
Near the south end of the garden, we spent a lot of time adding sandy soil to improve drainage so the rhododendrons can thrive. We were able to refresh and expand the growing areas for subsections Neriiflora and Thomsonia. These subsections include some species with the brightest red flowers and most beautiful peeling bark you will find among rhododendrons like Rhododendron meddianum var. atrokermessinum.
A personal favorite of mine that had been hidden deep on the edge of the garden but is now featured on the trail side is
In the same area, we removed a sprawling old hybrid rhododendron to make more room for subsection Irrorata, and also created a new growing area for subsection Ledum. Ledums prefer wetter feet than other rhododendrons but still need good drainage, so we found the boggiest spot and piled the sand a little less thick. We are experimenting with some carnivorous plants here and you will see a couple of different hardy pitcher plants (Sarracenia) alongside west coast native cobra lily (Darlingtonia californica).
We opened a short new loop trail on the hillside above the nursery. This sunny and relatively dry area will be home to a thicket of rhododendrons from subsection Triflora with the idea that these tall plants will provide a visual barrier between the garden and the nursery and dampen some of the highway noise. It is also sure to be a great area for color because these plants bloom heavily and reliably for us in other parts of the garden. In the driest parts of the slope, we are trialing some manzanitas (Arctostaphylos species). These rhododendron relatives are happy in pretty dry conditions once established. That makes them useful plants for us because we can use them to fill random spots in the garden that don’t receive enough water from the irrigation system for rhododendrons to grow well.
This area, called the Triflora Slope, is still a work in progress. We plan to finish planting it out in the coming year while also creating a new trail to connect it directly to the Azalea Garden. The trail will run along a neglected hillside where we can add soil and plant more azaleas. Beyond that, we also plan to fill in a couple of iris-filled swales in the Azalea Garden to provide more room for azaleas and other companion plants.
The Upper and Lower Woodlands have been receiving some attention as well with a mass of barberry (Berberis) removed to make room for more bigleaf rhododendron species like Rhododendron basilicum. This winter we plan to add a little bit of soil to a low spot in the Lower Woodland and plant out a grove of bigleaf magnolia (Magnolia macrophylla). We have lost some important canopy cover in this part of the garden in recent years, and we hope these magnolias will grow well and quickly. Eventually they will provide good shade for the bigleaf rhododendrons while also being just really cool trees.
If you haven’t been to the garden in a while, come and check things out this coming year because there are a lot of new things to see.