Tom Karwin

Anna’s hummingbird (Calypte anna). This female hummingbird has a dull green crown and
an iridescent red gorget (the band over the throat and chest). In comparison, the male has a crimson red crown and gorget. Both have pale bellies. This photo shows the bird feeding from
the inflorescence of a showy banksia (Banksia speciosa). The evergreen shrub or tree is an
Australian native and a member of the protea family (Proteaceae). (Credit — Brad Lewis)

Tom Karwin, On Gardening: Hummingbirds in flight

March 1, 2026 at 9:03 a.m.

One of nature’s fascinating aspects in the garden is the flight of hummingbirds. The UC Santa Cruz Arboretum & Botanic Garden will feature these avian phenomena during Hummingbird Month, starting...

Red velvet sage (Salvia confertiflora). This broadleaf deciduous, evergreen perennial has bright green new foliage that matures to dark green and reddish-purple stems. In the late summer and fall, the plant displays 6-to-10-inch spikes of fuzzy, rusty red flowers that rise above foliage. It grows 4 feet tall and 3 feet wide. The plant is native to Brazil. (Courtesy Tom Karwin)

Tom Karwin, On Gardening: Pointers for perennial plant propagation

February 22, 2026 at 9:10 a.m.

"Our column focuses on propagating herbaceous and woody perennials through stem cuttings. The process uses simple actions, requires few tools, takes little time or space and can generate many new...

Mid: Dwarf Mexican marigold (Tagetes lemmonii x patula ‘Gold Medal’). This shrub-like perennial grows to 2 feet tall with aromatic, dissected, medium green foliage and lightly fragrant,
gold-yellow daisy flowers that bloom heaviest from fall through late spring, and can stay in
bloom much longer. This plant is a hybrid of Mexican marigold (T. lemmonii), which can reach 6 feet tall, and the 12-inch-high French marigold (T. patula). (Credit — Jim Evans via
Wikimedia Commons)

Tom Karwin, On Gardening: Focusing on long-blooming perennials

February 15, 2026 at 10:53 a.m.

"Compared with annuals, perennials offer long-term beauty, require minimal maintenance and provide a foundational landscape that evolves over time," writes columnist Tom Karwin.

Chiapas sage (Salvia chiapensis). This Chiapas, Mexico, native plant’s natural habitat is a cloud forest; it grows in full sun or partial shade and reaches up to 4 feet high and wide. When
grown in a large container, it will be limited to 3 feet high and wide. From late summer
through winter, it develops bright rose-fuchsia-colored flowers with green calyces in well-spaced whorls of three to six flowers on erect, 1-foot-tall stems. As with many salvias, this plant should be cut back hard in late winter or early spring to encourage fresh new growth. (Courtesy Tom Karwin)

Tom Karwin, On Gardening: Growing plants from seeds

February 8, 2026 at 9:43 a.m.

Now is the appropriate time to plant seeds for spring blooms in the garden. Growing plants from seeds requires minimal time and effort and provides the satisfaction of real gardening...

Living stone (Lithops aucampiae). A small succulent with brown-red bodies consisting
of two fleshy leaves with darker markings at the tips. In time, the plant can develop a cluster of up to 12 bodies, each 2.2 inches tall and 1.5 inches wide. The leaves are
divided by a fissure from which new leaves and flowers appear. In the fall, 2-inch-wide daisy-like bright yellow flowers appear. Native of South Africa. I bought this plant for the fifth 4-inch wide container on my desk table. (Courtesy Tom Karwin)

Tom Karwin, On Gardening | Using AI to empower gardening

February 1, 2026 at 12:07 p.m.

"Our recent columns have focused on uses of artificial intelligence to select plants, address plant problems and design garden landscapes," writes columnist Tom Karwin. "AI resources can be useful in...

Salvia spathacea (hummingbird sage). Rosette-growing, herbaceous. (Courtesy Tom Karwin)

Tom Karwin, On Gardening: Scheduling care and maintenance

January 25, 2026 at 11:21 a.m.

"This column focuses on scheduling plant care and maintenance," writes columnist Tom Karwin. "We begin by reviewing different ways that gardeners acquire information about broad categories of plants (shrubs, trees,...

Strawberry tree (Arbutus unedo). A Mediterranean native, this small tree can exceed 20 feet in height but is easily maintained at under 7 feet tall. (Credit – Robert Perry)

Tom Karwin, On Gardening: Real gardening with AI — Problem solving

January 11, 2026 at 12:05 p.m.

"Our current topic concerns ways a gardener can use AI to answer questions and solve problems in their garden," writes columnist Tom Karwin. "The emphasis is not on generic gardening...

Jellybean (Sedum pachyphyllum). This ground-hugging, spreading succulent in the Stonecrop plant family (Crassulaceae) reaches 11 inches in height. A native of Mexico, this drought-tolerant plant grows well in full sunlight. In winter, the tips of its short, stumpy, silvery-green leaves turn red. (Courtesy Tom Karwin)

Tom Karwin, On Gardening | Real gardening with artificial intelligence

January 4, 2026 at 11:58 a.m.

"Gardeners can use AI technology to manage routine tasks, improve the accuracy and timing of decisions, learn faster from the garden, and free up attention for observation, enjoyment and creativity,"...

Pigsqueak (Bergenia cordifolia or B. crassifolia). This perennial blooms from late winter to spring and exemplifies large, rounded, leathery, evergreen leaves. Gardeners can appreciate the plant’s common name by rubbing the leaves between their fingers. The plant is native to Russia and a member of the saxifragaceae family. (Courtesy Tom Karwin)

Tom Karwin, On Gardening | Focusing on foliage

December 13, 2025 at 3:54 p.m.

"Many flowering plants are currently dormant, so the current season presents an ideal time to 'dive' into the garden’s foliage," writes columnist Tom Karwin. "Gardeners greatly appreciate the garden’s blossoms,...

Red chestnut bromeliad (Vriesea fosteriana var. seideliana ‘Red Chestnut’). (Courtesy Tom Karwin)

Tom Karwin, On Gardening | Exploring the subfamilies of blooming bromeliads

December 7, 2025 at 10:31 a.m.

"The bromeliads comprise one of the most eclectic plant families in the Americas, including epiphytes in rainforests, terrestrial species in high elevations and arid-land survivors," writes columnist Tom Karwin. "Taxonomists...

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Tom Karwin, On Gardening: Hummingbirds in flight

Tom Karwin, On Gardening: Scheduling care and maintenance

Tom Karwin, On Gardening: Real gardening with AI — Problem solving