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Author Archives: Caity Chandler
We Have Roots!
The island’s first purpose as a military prison introduced the construction of the Sally port and this is where all visitors first walk by today on their way up to the cell house. Before entering the Sally port, they are greeted with the island’s first garden and home to some survivor plants thought to be planted in the 1920s. Among this bed are two historic Cordyline that are very old and are showing signs of decline. The Cordyline australis planted in the Sally port gardens is an old variety and have been very hard to find in the nursery trade. The Cultural Landscape report suggests that these be replaced, but not until we have the same plant with the same genetic makeup of the replacements.
In efforts to replace these declining historic Cordyline, we have tried several propagation methods to ensure they remain as part of the gardens for years to come. All of the methods were done in mid-March and we recently have had some promising results. Below are detailed descriptions of the propagation techniques trialed.
Methods of Propagation
Cutting:
We first tried just a cutting of one of the canes and potted it up in a pot of our compost. We removed some of the foliage and trimmed some of the fronds back to reduce that amount of energy going into the foliage and instead put it into the formation of roots. At first, it seemed as though this method might work, but after about a month, the fronds were almost all dead. The cane itself had become soft and the inside had become rotten. I think this method would work using a thinner cane or a smaller one with less foliage.
Layered:
For this method, we took three pieces of cane, about 6 inches long each and laid them horizontally, half way deep, in a tray of sphagnum peat moss mixed with our compost. I had thought this method would work best, and we actually did have roots start to form alongside the canes, but I think they ended up getting over watered and the canes started to rot. Unfortunately, all three were unsuccessful. I think if we were to try this method again, we would use a different media composition and not allow the soil to get too wet.

Top left: Bark removed around cane. Top right: Cane wrapped with soaked peat moss and plastic. Bottom left: Plant removed from mother plant. Bottom right: Roots shown after unwrapping the plastic.
Air layering:
The air layering method turned out to be the most successful of the three that we tried. This method is actually done on the mother plant itself. We started by soaking sphagnum peat moss for a few hours. This is crucial to keep the stem moisturized to allow roots to form. On one of the canes, we cut an inch wide ring through the cambium layer and removed the bark around the cane. Next, we took the soaked peat moss and wrapped it around the cut tightly and then wrapped it with plastic wrap and tied string around it to hold it in place. We did this twice more on separate canes. We recently cut the three successful air layered canes from the mother plant because roots had formed and they were ready to be potted up. We first soaked them before potting them to allow the peat moss to rehydrate. We put the new plants in five gallon containers and they are happily living in our greenhouse until they reach a more mature state with more developed roots to replace the ones at the Sally port.
The air layering method can be used for other woody shrubs and works well for some trees. This method does take a while to see some roots form, but once they do and it is cut from the mother plant, you already have a bigger plant than you would if you propagated it by seed or a cutting.
To replace the survivors, it is important that they are replanted with the same species of the current Cordyline. By propagating them by the methods we tried, it ensures that the replacements have the same genetic makeup of the current plants. We are very excited to have successful clones to replace the current failing Cordyline.
Posted in Gardens of Alcatraz, Plants, Uncategorized
Tagged air layering, cordyline, Propagation
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Invasive vs Naturalized
The term ‘invasive’ is often misused to label plants or anything that is intrusive in the natural environment. It is something I have only recently began to question. What actually validates a plant being invasive? (I’m going to stick to just talking about plants… I am a gardener after all!) My experience with talking to the public when removing invasive or unwanted plants has been pretty limited, but this past week as I was weeding the lawn, a guest on the island asked me, “Are you weeding invasive grasses?” Without really thinking about the question, I said, “Yeah.” The grasses we were removing from the lawn were crabgrass, annual bluegrass, and rattail six weeks grass. After he walked away I was left thinking, “Are those really considered ‘invasive’?” This led me to a bit of research in pursuit of an answer…
Plants that are invasive are actually scientifically categorized as so. It seems like scientists also have trouble labeling whether or not a plant is invasive or how plants can eventually become invasive over a long period of time. Plants that aren’t native to an area aren’t considered to be an invasive species until they have a negative impact in disrupting a native area. The displacement of native species and the ability for a non-native to cause economic and human harm are the two attributes for a plant becoming an invasive species. The Environmental Detection Distribution and Mapping System (EDDMS) have a simple list of characteristics showing the differences between an invasive and an ornamental plant:
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(https://www.eddmaps.org/about/why_plants_invasive.html)
The three grasses we were removing from the lawn are actually not on the invasive list for California. They are weeds, unwanted in our native sedge lawn, but aren’t labeled as invasive. Plants can however become invasive over a period of time. Because of this, it’s important to monitor non-natives and their growth in native areas.
This graph is a good representation of how plants begin to become a threat to natives and the actions that should take place to keep it under control.
(https://www.eddmaps.org/about/why_plants_invasive.html)
During the lag phase and early recognition is when it is less costly and easier to eradicate. To prevent plants from reaching levels of higher efforts to control, it is crucial to catch them and be aware of the plant’s potential threat to a native area.
So, with all that being said, let’s see if we can clear up some misunderstanding on a few plants that call Alcatraz home. I think my favorite example, is the Echium candicans or commonly known as Pride of Madeira. It is a plant native to the island of Madeira, but has been introduced to the coast of California and thrives very well here. Many think that this plant is invasive because it is found among the hillsides and coastal bluffs mixed with native plants. Although it does spread fairly easily, it has shown no threat to native plants and is listed on the California Invasive Plant Council, (Cal-IPC), as a limited threat. It is a well admired plant on the island and copes well with the high winds and little rainfall. It is an island survivor plant that has naturalized itself and is a great pollinator for bees.
On the other hand, English ivy, (Hedera canariensis), is a plant that is considered to be a high threat on the Cal- IPC list. It is found all over the island and was one of the more prevalent plants contributing to the overgrowth in the gardens and is still a plant that we are consistently working on cutting back to keep it at bay from the garden beds. In other overgrown areas though, the ivy plays a vital role during water bird nesting season. They use the ivy overgrowth as a nesting site to lay their eggs and raise their young. Himalayan blackberry (Rubus armeniacus), is another plant found on the island that is listed as a high threat and we eradicate it from the garden beds, but leave it be in overgrowth areas because the birds also use it for nesting.
Jupiter’s beard (Centranthus ruber), and Mimosa tree (Albizia distachya), are examples of plants on the island that are commonly mistaken as invasive. They both are island survivors and spread fairly easily, but neither is listed on Cal-IPC as invasive. We like to use the term ‘aggressive’ and we monitor them and remove any unwanted seedlings. The mimosa tree is a nesting site for Anna’s hummingbirds and Jupiter’s beard adds a seasonal burst of color throughout the gardens.
I hope this clears up some confusion about what invasive actually signifies. Just because a plant isn’t native doesn’t make it invasive. The invasive plants on the island are kept in check and tell the story of the islands past gardeners. For today’s gardeners, you should check local plant lists for invasive species before purchasing.
Posted in Plants, Uncategorized
Tagged albizia, alcatraz gardens, centranthus, echium, hedera, invasives
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Wrongfully Convicted – Life of a Banana Slug
Most gardeners hear the word slug and immediately have a negative thought about them being destroyers of their beautiful plants and I was guilty of this assumption too when I first heard banana slug. In most cases they are a nuisance, but the Pacific banana slug (Ariolimax columbianus), along with its other two relatives, the California banana slug (A. californicus), and the slender banana slug, (A. dolichophallus), have a different role in the environment. Banana slugs are detritivores (decomposers) and thrive on dead plant material, mushrooms, animal droppings, moss, and leaves. They recycle these materials and help with the dispersing of seeds and spores as well as take part in creating nitrogen rich fertilizer. The dead organic matter they consume supports decomposition on the forest floors and aids in nutrient cycles.
- Banana slug party on Alcatraz after the first rain. Photo by Caity Chandler
Banana slugs are primarily found in the Pacific Northwest, ranging from southern California up to Alaska and are home to moist, temperate, forest floors. They are the second largest slug in the world, reaching up to 10 inches (25 cm) in length and can live to be seven years old. They get their name because of their yellow coloring, resembling a banana, but can also take on dark spots or even become a little greenish. This is caused by a number of things such as their food consumption or the light or moisture levels they are exposed to and even the health of the slug. They have two sets of antennae that serve different purposes. The shorter set is used for sensory while the longer pair is used for sight.

Just a handshake today, no licking. Photo by: Shelagh Fritz
One of banana slug’s unique characteristics is their slime. Banana slugs are prey to raccoons, garter snakes, ducks, and geese, but their slime serves as an anesthetic to predators causing their mouth to go numb if they dare take a bite. The slime isn’t toxic to humans and people have been known to lick them to test the theory of the numbing sensation. I personally haven’t tried it, but know people that can attest to its factuality. Another benefit of the slime is its ability to help them retain moisture. Banana slugs are mostly water and are prone to desiccation. The slime actually helps attract water and has the potential to absorb up to 100 times the slugs water weight. Slime also supports the banana slug’s mobility in navigating through the forest, gliding over dirt, leaves, and other debris.

Love at first sight. Photo by: Shelagh Fritz
Being new to the West Coast, I was unfamiliar with the banana slug’s positive influence on the forest floor and contribution to the soil. I thought they were a nuisance to the garden and plant life similar to other slugs, but in fact they are an important aspect of the ecosystem assisting in decomposition. The banana slugs still remain happy, innocent, inhabitants of the island. I was very excited the first time I spotted one and after I saw one, I must have seen 30 that day. Keep your eye out for these cute little guys on moist days and appreciate their positive impact in our beautiful forests. Hugs for slugs!