We recently featured the unusual inflorescence of a pineapple mountain (Ochagavia litoralis), a Chilean bromeliad. The plant has grown in my garden since 2018 and bloomed for the first time this year.
This startling event motivated us to examine the plant and learn more about it.
We first focused on the plant’s multiple offsets. These rosettes can be divided and planted to generate several identical plants and a future display of striking inflorescences.
The plant blooms during September and October and will fade in November or perhaps later. We will schedule the division of the rosettes after the blooms fade.
Meanwhile, this column explores the propagation of plants with foliage in rosette form.
Rosette-formed foliage
Here’s Wikipedia’s definition of the botanical form called a rosette: “a circular arrangement of leaves or of structures resembling leaves.” This form occurs in many plants, particularly succulents.
Additionally, some vegetables also exhibit a rosette form, including lettuce, Brussels sprouts and cabbage. The form also exists in weeds (such as dandelions and plantains) and perennials (including foxgloves, primroses and ferns).
The large rosette-formed succulent genera include agave, aloe, bromeliad and mangave. Other examples of succulents with rosette forms include snake plant (Sansevieria), echeveria, gasteria, haworthia and hens and chicks (Sempervivum).
Propagation of succulent rosettes
Plants in this category propagate when two individuals combine to produce seeds that eventually germinate, drop to the soil, take root and form a new plant. This is sexual propagation.
Some plants also have an asexual form of propagation, which creates clones of the original plant. One way this occurs is when a leaf falls from the plant and takes root in the ground.
Another approach to asexual propagation occurs in some species through the production of offsets (called “pups”). This results in a clumping growth habit.
Gardeners can easily pull some offsets from the parent plant for planting separately. An example is hens and chicks (Sempervivum).
In some plants, the gardener needs to cut the offset from the parent plant. This is the easiest way to propagate rosette-formed succulent plants, and can be done with agaves, aloes, bromeliads and mangaves.
Ideally, the gardener should cut offsets in the spring, when the plant is ready to grow, rather than while it is in bloom. During that period, the plant is sending its energy into bloom production.
Usually, this may require removing the entire plant from the pot before separating the pups.
The offset has already developed some roots, and the gardener can easily transplant the offset. Good practice includes letting the cut callus for a day or two, then placing the offset in well-drained soil and waiting until the plant shows new growth above the soil before watering.
Agaves and mangaves (properly referred to as xMangaves), when grown under favorable conditions, can produce offsets readily.
Some gardeners do not favor the asexual propagation of succulent plants because they accumulate more new plants than they want or for which they have garden space. These gardeners can select plants that limit sexual propagation.
Botanists refer to agaves that typically do not produce offsets as “solitary” plants. Dozens of agave species are reliably solitary. As with the plant kingdom, exceptions can happen.
Mangaves reportedly always produce offsets and do not include solitary species. However, these hybrids are relatively new in gardening and can include cultivars that also produce flower stalks.
Replanting offsets
Once the plant has produced several offsets, the gardener’s options are to transplant the offsets as an expansive colony with the parent plant, as two or more separate small colonies, or as standalone features. When gardeners have more offsets than they want or need, they can share them with other gardeners or compost the excess.
Offsets can be free additions to the landscape, generated by nature.
Advance your gardening knowledge
When dividing a succulent rosette, particularly if it’s an unfamiliar specimen, the gardener can find helpful information by searching for “dividing (plant name)” on the internet for recommendations or searching YouTube for video demonstrations of the technique.
Increasingly, gardeners can readily draw upon artificial intelligence tools to generate more detailed presentations of cultivation methods. One can generate even brief AI presentations on topics of interest using a Chrome browser, without needing to register for an AI utility such as ChatGPT.
Mark your calendar
The Santa Cruz County Chapter of the California Native Plant Society will hold its Fall Native Plant Sale at Cabrillo College Horticulture Center in Aptos Oct. 11, from 9 a.m. to 1 p.m.
These sales consistently offer gardeners excellent opportunities to acquire new California native plants for their landscapes. The local California Native Plant Society members grow locally native plants, which Monterey Bay area gardeners can grow readily, and the area’s wildlife will appreciate.
The early word is that this sale will be outstanding. Watch this column for updated information and monitor the Society’s new website at chapters.cnps.org/Santacruz for the sale’s plant list.
Enjoy your garden!
Tom Karwin can be reached at gardening@karwin.com.
