Tom Karwin, on gardening | Gardening with Mexican succulents

Today, we address two topics.

The first topic came to mind from an online talk in which the speaker described 20 succulent plants that appeal to gardeners who want to avoid plant maintenance. He briefly described succulent plants that require minimal irrigation and little other care in the garden.

He included succulents from both Mexico and South Africa, which are the habitats of most succulents. A few other succulent plants grow natively in the Mediterranean Basin, which includes the nearby Canary Islands, home to Aeoniums and a few other succulent genera.

This column focuses on succulent plants from Mexico and builds upon the online talk.

Our second topic, gopher control, follows below.

Today’s gallery of images

The photo gallery shows a small selection of native Mexican succulents in my garden. I also grow many succulent plants native to other regions.

Low maintenance plants

Succulent plants have garden appeal for their varied, interesting, often architectural structures. My garden includes collections of Mexican succulents, with one bed comprised of diverse cultivars and separate beds for Agave and Mangave species. These beds have slightly mounded forms to ensure adequate drainage and use gravel dressing to prevent weeds and provide a natural setting.

Succulents require only easy maintenance. In the Monterey Bay area’s summer-dry climate, these grow easily with minimal or no irrigation and increase slowly in size.

In summer, succulents create floral displays to color the landscape and drop seeds. Some varieties bloom for only short periods, and few blossoms succeed as cut flowers. Their visual appeal is primarily based on the color, shape and structure of their leaves.

Succulent plants depend on fleshy leaves, stems and roots to retain moisture. Some succulents, mostly those in the cactus family (cactaceae), protect themselves from predators with formidable spines that some gardeners find attractive and others regard as fearsome.

Safe practices include planting spiny succulents away from pathways, weeding around them with tongs and wrapping them in a towel or other thick fabric before transplanting.

Most succulents self-propagate by forming offsets that gardeners can easily divide to plant in preferred sites, share with other gardeners or discard. Gardeners can propagate succulents that produce seeds rather than offsets by planting leaves or stem sections lightly in soil, where the plant part will soon develop roots.

Landscaping with succulent plants

Generally, plant succulent plants apart from plants that depend on regular irrigation. Hydro-zoning optimizes irrigation efficiency, conserves water, improves plant health and avoids watering succulents, which can cause root rot.

Combining different succulent species can be based on plant communities, if the gardener researches the species’ habitats. Some succulents grow naturally in coastal environments. For example, coast prickly pear (Opuntia littoralis) occurs in coastal scrub communities alongside compatible plants like California sagebrush (Artemisia californica), bush sunflower (Encelia californica), California buckwheat (Eriogonum fasciculatum) and other Opuntias.

A simpler landscaping strategy for Mexican succulents is to group plants by size, with larger plants behind smaller ones. That display might not reflect a natural plant community, but it provides interesting contrasts in plant forms and colors.

Another approach is to create a cluster of plants of the same species, for visual effect. This approach can be applied with golden barrel cacti, for example. Different specimens of the distinctive plants could vary in age and size, providing a varied yet coherent display.

As noted above, my garden includes separate beds for Agave and Mangave cultivars, which differ in size, leaf color and leaf forms, providing views of the variations within the genera.

Finally, a landscape designer can highlight exceptional succulents, particularly larger cultivars, by positioning them alone or surrounding them with smaller, less prominent succulents.

Advance your gardening knowledge

Another topic: gopher control

Column readers have asked how to control or get rid of gophers in the garden. The University of California’s Agriculture and Natural Resources website has 399 articles on this subject, making it among the most pressing issues for gardeners.

That’s too much to read, so I prompted ChatGPT to summarize the topic, based on the Agriculture and Natural Resources articles. It produced a seven-page summary, with photos, and offered to produce a control plan. I requested the plan, and the system generated a two-page annual calendar for gopher control in the Monterey Bay area.

The month of May is the time for the dispersal of young gophers. Gardeners are likely to see a new peal of gopher activity at this season. My further research with AI indicated that gophers commonly damage plants with soft, moist roots, fleshy crowns, bulbs, tubers or newly developing root systems. Otherwise, gophers have little interest or resistance to plants with toxic sap, aromatic foliage, leathery leaves, fibrous roots or coarse textures.

Here is AI’s list of 10 plants commonly damaged by gophers in Central Coast gardens: Rosa, Dahlia pinnata, Tulipa, Lilium, Hemerocallis, Leucadendron, Grevillea, Ceanothus, Lactuca sativa (lettuce) and Solanum tuberosum (potato).

AI also listed these gopher-vulnerable plants: artichokes, carrots, bearded iris, succulents with soft roots, young citrus trees, apple trees, avocado trees, newly planted California natives, chrysanthemums and alstroemeria.

Then, here is AI’s list of 10 plants that gophers tend to avoid: Agave attenuata, Aeonium arboreum, Lavandula angustifolia, Rosmarinus officinalis, Salvia clevelandii, Euphorbia characias, Nerium oleander, Artemisia californica, Iris douglasiana and Achillea millefolium.

AI also listed many gopher-avoided plants: salvias, daffodils, society garlic, Westringia, rockrose (Cistus), lion’s tail (Leonotis leonurus), basket grass (Lomandra), aloes and many bromeliads.

Search the internet by the names of unfamiliar plants for more details.

Based on this AI-generated information, we recommend controlling gophers by favoring gopher-avoided plants and installing vulnerable plants in gopher baskets.

The least expensive and easiest-to-install gopher baskets are those made of stainless-steel mesh. These can be effective, but experienced landscape gardeners advise that mesh baskets constrain root growth and are inappropriate for woody or herbaceous plants that will grow large and need root space.

Heavy-duty wire baskets are more difficult to install and more costly, but they are better choices for plants that grow and need to extend roots through the basket’s spaces. These baskets are more costly than mesh baskets at garden centers. I found the best prices online at Amazon.

The cost and effort of installing preferred gopher baskets is better than replacing plants, more reliable than trapping gophers and more environmentally friendly than poisoning animals.

This week in the garden

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 & Succulent Society, a Lifetime UC Master Gardener (certified 1999-2009), past board member of the Santa Cruz Hostel Society and a current member of the Pacific Horticultural Society and other garden-related societies. To review the archive of recent On Gardening columns, visit santacruzsentinel.com and search “Karwin.” Visit ongardening.com to review columns from 2012-2020 (and eventually) from the following years. Please send comments or questions to [email protected] via email.