Cabbage tree (Cordyline australis ‘Burgundy Spire’). This Australian native is a flowering, evergreen, multi-trunked tree that can grow to 30 feet tall in its native habitat. The sword-like leaves are 3 feet long and 3 inches wide. The cabbage tree produces small, fragrant flowers in the late spring. My specimen, currently about 10 feet tall, is in bloom now, as shown. This tree is a member of the asparagus plant family (Asparagaceae). (Courtesy Tom Karwin)
White Australian fuchsia (Correa ‘Ivory Bells’). A San Francisco plantsman developed this evergreen shrub, a hybrid of two correa species in the citrus plant family (Rutaceae). It grows to 5 feet tall and wide, featuring attractive, dense growth of downy, gray-green foliage. During fall, winter and early spring, it develops delicate, tubular, ivory-white, bell-shaped flowers that attract honey-eating birds, especially hummingbirds. The genus name honors Portuguese botanist Correa de Serra. (Courtesy Tom Karwin)
Spider net grevillea (Grevillea fililoba). This broadleaf, evergreen shrub, another member of the citrus plant family (Rutaceae), was first formally described in 1986. It grows 3 to 5 feet tall and wide and, from July to September, produces long-lasting, pinkish-red flowers that attract hummingbirds. It is readily grown from seed or cuttings and thrives in the Monterey Bay area when given well-drained soil and full sun exposure. (Courtesy Tom Karwin)
New Zealand Christmas tree or iron tree (Metrosideros kermadecensis ‘Variegata’). In its native habitat, this tree can grow up to 80 feet high but the cultivar in my garden should be 6 feet high and wide. It flowers from November to January, peaking in mid to late December, when brilliant crimson flowers cover the tree. The generic name is based on Greek words meaning “heartwood” and “iron.” The species name is from the Latin word for “highest, sublime.” The Māori name for this plant is pōhutukawa. It is native to New Zealand and a member of the myrtle plant family (Myrtaceae). (Courtesy Tom Karwin)
Coast rosemary (Westringia fruticosa ‘Morning Light’). References to this plant describe a small, compact shrub that grows 4 feet tall and 5 feet wide. It has tightly crowded linear leaves with a cream-colored variegation along the margins. The foliage is the showiest aspect of this plant; it produces small white blossoms during a flowering period that lasts year-round in coastal gardens. This plant is a member of the flowering plant family known as the mint, deadnettle or sage family (Lamiaceae), which includes widely used culinary herbs such as basil, mint and rosemary, as well as traditional medicinal plants like catnip. (Courtesy Tom Karwin)
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Cabbage tree (Cordyline australis ‘Burgundy Spire’). This Australian native is a flowering, evergreen, multi-trunked tree that can grow to 30 feet tall in its native habitat. The sword-like leaves are 3 feet long and 3 inches wide. The cabbage tree produces small, fragrant flowers in the late spring. My specimen, currently about 10 feet tall, is in bloom now, as shown. This tree is a member of the asparagus plant family (Asparagaceae). (Courtesy Tom Karwin)
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The fall season offers opportunities to walk through your garden, spot problems to solve and plan improvements. You can review your whole garden or focus on a particular area.
Today’s image gallery
This column’s photos showcase some of the larger plants in my Australian garden that I focused on during my garden review.
Beginning a seasonal review of the garden
My garden includes separate sections for Mediterranean climate regions. My seasonal garden review is most effective by focusing on one section at a time. Today’s column summarizes my review of the Australian section, which has an irregularly shaped area of about 350 square feet.
My gardening practice resembles that of most active gardeners, so that at any given time, the garden includes mature plants, newly installed plants, young plants, well-rooted plants and unhappy plants that have — or nearly have — expired.
Unhappy plants
A first step in the seasonal review can be the decision to remove plants that are not doing well. They might have only crinkly dry leaves, show signs of wilt or disease, or a lack of healthy growth. The gardener might blame insufficient cultivation, the right plant in the wrong place or an undetermined failure.
The positive perspective for “shovel pruning” plants is to release space for additions to the landscape.
My review of the Australian section easily identified two plants that hadn’t succeeded. Space is now available for two new native Australian plants: an orange libertia (Libertia peregrinans) to replace one that had not succeeded, and a white striped flax lily (Dianella tasmanica ‘Variegata’) that caught my eye at Cabrillo College’s recent plant sale.
These two new specimens are among the recently installed and young, already well-rooted plants in the Australian section.
Well-established plants
Well-established, mature plants can be landscape anchors, providing a context and foundation for other plants. An example of such plants in my Australian section is a white Australian fuchsia (Correa ‘Ivory Bells’). Today’s image gallery shows the blossoms of this plant. It has been growing nicely and could benefit from light pruning.
It is also possible that the gardener regards some mature plants as overgrown and in need of pruning, not contributing to the evolving landscape, or no longer as interesting and occupying space for appealing new plants.
Another mature shrub in the Australian section is a coast rosemary (Westringia fruticosa ‘Morning Light’). This plant has expanded to 6 feet tall and 8 feet wide, larger than its reported mature size of 3 to 4 feet tall and wide. While I appreciate the growth of plants in my garden without much care, this plant is expanding beyond the intended site and intruding into the pathway.
An internet search for “pruning westringia fruitcosa” yielded this recommendation: “Late spring and early summer pruning aligns with a period of rapid growth and recovery for coastal rosemary, ensuring minimal stress and optimal plant vigor. These seasons are considered optimal for pruning coastal rosemary because they coincide with the post-flowering period and the onset of the plant’s active growth phase.”
If I prune this shrub in the fall, I could stress the plant and reduce its flowering the following year. My options are to prune the plant now and live with these risks, schedule pruning for next year’s late spring or remove the plant.
Mature and uncommon plants
Another mature plant in the Australian section is cordyline australis ‘Burgundy Spire,’ which is commonly known as the “cabbage tree.” Wikipedia reports that the common name is “attributed by some sources to early settlers having used the young leaves as a substitute for cabbage.”
This plant has already grown to about 10 feet tall and could achieve as much as 30 feet in height. It grows slowly and has room for greater height, so its size is not a concern of mine.
This tree’s first appearance of an extraordinary inflorescence features hundreds of flowers. This is not an ordinary inflorescence. It begins with a peduncle (a stalk supporting the inflorescence), several panicles (a loose, branching cluster of flowers) and a compound racemose type of inflorescence (short floral stalks along the shoots that bear the flowers).
The small blush-pink, star-shaped flowers reportedly have a jasmine-like fragrance. The blossoms have already been replaced with small ivory-colored berries.
Today’s image gallery shows this plant’s peduncle.
Advance your gardening knowledge
Calscape, a tool of the California Native Plant Society, has announced the beta version of the new, online Pollinator Companion tool to support pollinator gardening. The California Native Plant Society is partnering with researchers to measure how online tools can support pollinator-friendly gardening. Calscape invites California gardeners and farmers to try this tool and provide feedback through a brief survey. Participants will have a chance to win a $10 gift card. To try this new tool, go to: morphonativeplants.github.io/redirect.
This week in the garden
Assess your garden plants now, at the end of their growing season, to determine if they have become too large for their site or if they should be moved elsewhere to create space for new plants. If needed, relocate them for spring growth and install new plants to develop roots during the rainy season.
Now is the time to plant bulbs to bloom in the spring. For sources of ideas, recommendations and online offers, browse the internet for “spring bulbs.”
For a wide range of seasonal tasks, read Megan Hughes’ Fall Garden Checklist at bhg.com/gardening/yard/garden-care/fall-garden-checklist.
Enjoy your garden!
Tom Karwin is a past president of Friends of the UC Santa Cruz Arboretum and the Monterey Bay Iris Society, a past president and lifetime member of the Monterey Bay Area Cactus and Succulent Society, a Lifetime UC Master Gardener (certified 1999-2009), past board member of the Santa Cruz Hostel Society and active with the Pacific Horticultural Society and other garden-related societies. To view photos from his garden, visit facebook.com/ongardeningcom-566511763375123. To review the archive of recent On Gardening columns, visit santacruzsentinel.com and search “Karwin.” Go to ongardening.com to review columns from 2012-2020 (and soon) from 2025. Send comments or questions by email to gardening@karwin.com.
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