Garden archeology

Past garden manager, Carola, is quoted in Alcatraz’s Discovery film as saying the gardening is like ‘garden archeology’. Her words perfectly described the work of clearing vegetation and finding artifacts and landscape features that had lay hidden underneath ivy and blackberries for decades.

Her words are still very true today. The garden crew has been in over their heads clearing ivy from trees and uncovering terrace walls.

Volunteers clearing ivy from terraces. Photo by Shelagh Fritz

Volunteers clearing ivy from terraces. Photo by Shelagh Fritz

Using the Cultural Landscape Report for Alcatraz Island as a guide, permission was granted by the Park Service to clear overgrowth from known garden areas that no one had worked in since the prison closed in 1963. As part of the approval, garden volunteers and staff attended a lecture by National Park Service Archeologists, Leo and Peter.

Leo giving his presentation to garden volunteers. Photo by Shelagh Fritz

Leo giving his presentation to garden volunteers. Photo by Shelagh Fritz

With broad reaching strokes, Leo and Peter described their work across the park. San Francisco has a rich history with native settlements, missions, military history. Every time significant ground disturbance is done in the Park, this duo is on the scene. Some finds are accidents whereas others are known sites of interest. Leo described what to do in case items were found –

-take a photo with a point of reference in the background, not to zoom in on the object but give an easy way to find where the object had been found.

-fill out the paperwork that marks on a map where the object was found, and describe the item and the circumstances under which it was found

A key point was to distinguish between a single item found and a ‘feature’. A feature, as we now know, is considered a group of artifacts. In the case of finding a feature, the objects should be left in place and give Leo a call.

Barbara finding an intact bottle. Photo by Shelagh Fritz

Barbara finding an intact bottle and spoon. Photo by Shelagh Fritz

All of the objects found are taken to the Presidio archives where they are cleaned, recorded, and added to the collection. For garden artifacts, Leo has been marking the locations of the items on an overall map. Overtime, the pinpoint locations of objects give a big picture of significant areas, slow archeology in a sense.

Most people think of Alcatraz as only a federal prison, but the island has layers of history that equals the city of San Francisco, where the story of the gardens is woven throughout. Seeing the island through Leo’s eyes was really, well, eye-opening. Landscape features that we always walk by, were given an explanation, or at least a theory that made us all think – ah, that makes sense. For example, many parts of the island had a whitewash over the bricks, stone and concrete. The whitewash façade has fallen away in many areas, but the anchor holes of the façade remain.

Bolts holding whitewash facade in place along the Main Roadway. Photo by Shelagh Fritz

Bolts holding whitewash facade in place along the Main Roadway. Photo by Shelagh Fritz

Today, the holes look like planting pockets. We had always wondered about the evenly spaced shallow holes. They obviously weren’t big enough for a large plant with roots, or even to hold moisture during the dry summer. With Leo giving his theory of the holes being the anchor points, the holes suddenly made sense. By chance, the cliff below the Warden’s house is being stabilized with the addition of fake rock being anchored with long bolts – just like was done long ago.

Holes left behind by anchor posts for whitewash? Perhaps... Photo by Shelagh Fritz

Holes left behind by anchor posts for whitewash? Perhaps… Photo by Shelagh Fritz


One of the coolest objects found was an arrowhead several years ago, and another arrowhead showed up a few months ago. Leo explained that the arrowheads can be dated by using the fact that glass absorbs water at a specific rate for locations.


Other features of the island, are fun to speculate over – the bluestone found on the island is only found in a few locations around the Bay Area, Angel Island and Corte Madera. Not only did significant labour went into gathering the bluestone and hauling it to Alcatraz, but seeing it used for building reflects a known time period and a recycling of building material as well. Leo’s passion was evident as he said ‘some we will never learn but there is meaning in it all’.


Our take away lesson from Leo’s talk was to “overly thoughtful and nerdy about everything you find”.

Bluestone and bricks used to create a wall below the main roadway in Officers' Row. Photo by Shelagh Fritz

Bluestone and bricks used to create a wall below the main roadway in Officers’ Row. Photo by Shelagh Fritz

Posted in Artifact, Gardens of Alcatraz, History, Preservation | Tagged , | Comments Off on Garden archeology

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 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

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

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!


Posted in Wildlife | Tagged | 2 Comments

Concrete Preservation on Alcatraz

Did you know that when the cell house on Alcatraz was completed in 1912, it was the largest steel reinforced concrete structure in the world?

The world of concrete has come a long way since then, becoming the main building material in pretty much everything from buildings to bridges, and is actually the world’s second most consumed material (water is first). Fittingly, Alcatraz continues to play a part in the latest technology for concrete with the Concrete Preservation Institute.

A National Park Service Partnership began with a school program based out of Chico State University for students in Concrete Studies to have hands-on experience. Alcatraz happens to be an island full of concrete that is weathering in the salty wind that offers endless projects to students.

Summer 2015 Class. Photo courtesy of CPI.

Summer 2015 Class. Photo courtesy of CPI.

Much like the Alcatraz Historic Gardens Project, the Concrete Preservation Institute program quickly grew and, as of 2015, is now its own separate ‘non-profit educational foundation that advances the industry and partners with the US National Park Service at Alcatraz Island to preserve landmark structures’.

Personally knowing very little about concrete, other than it is strong, I wanted to know more about how the students worked their magic of transforming deteriorating railings back into new. Catrina, a current student of the program, and Scott, one of the programs leaders were generous with their time to answer my questions.


The concrete preservation projects the team works on are decided by a Projects and Stewardship committee of staff from the National Park Service, the Golden Gate National Parks Conservancy and the CPI team themselves. As the program continues, the student’s projects are getting more complicated and more skilled. However, the gardens offer a fairly straightforward project with the many concrete panel railings in the Rose Terrace and Officers’ Row. For each project, students learn project management and hands on training doing the work. For management, students run the project and comply with NPS protocols such as providing an existing conditions report, historical report and taking in progress photos to document the work. The hands on training involves drawing the railings to scale in blueprints, building the forms and learning how to work with the various materials with safety as a priority.

CPI students removing forms on a concrete railing. Shelagh Fritz photo

CPI students removing forms on a concrete railing. Shelagh Fritz photo

In her own words, Catrina is embracing CPI for what it is; a once in a lifetime opportunity to be a part of becoming an asset to history. “I am learning so much here. Other internship would be all paperwork and no application of skills. This is what makes CPI different. We learn from instructors who have dedicated their lives to the concrete Industry”. The students frequently receive visits from people who literally write the textbooks students use in concrete engineering majors!

Q: Can you tell me a bit about the program itself?

A: CPI is a twelve weeks program open for college students and post nine eleven veterans. There are 3 sessions per year. CPI teaches students research & technology innovation, tool knowledge and application skills, importance of industry job site safety, and using skills to apply to preservation of Alcatraz. There are people from many different educational backgrounds in this program. Some participants educational background range from construction industry management, civil engineering, biology, megatronics engineering, and architecture. Several people involved are both in schools and active duty servicemen and vets who served in Iraq. Veterans are always urged to join CPI program. I believe this program is an amazing opportunity for anyone who is involved.

Q: What makes the concrete you are using now special?

A: The concrete we are using is manufactured by BASF to add extra features to withstand the elements which typically limit the longevity of concrete. We mixed fibers in the mix for the panels of the railing because those areas are subjects to a greater weight load because of the top portion of railings. The panels are only 2″ in thickness so the panels have stainless steel threaded rods (the new rebar) embedded in them. Cracking over time is natural process in concrete because the rebar corrodes. The synthetic fibers never break down and so in theory, the concrete should last indefinitely.

New railings in the rose terrace. Photos by Shelagh Fritz

New railings in the rose terrace. Photos by Shelagh Fritz

Catrina was initially informed about this opportunity from her program director at New Jersey Institute of Technology. The current session finished on August 21 program and she will have a greater advantage for applying for fellowships and scholarships. In the fall, Catrina will continue her schooling at New Jersey Institute of Technology for her engineering degree in concrete industry management and construction management. Her future is bright with limitless possibilities.

With the abundance of concrete in the world, skilled people will be very much in demand to care for aging structures. Students will either go directly into the industry after their internship or will return to school to study chemistry, biology or architecture.



Posted in History, Preservation, Rehabilitation | Tagged | Comments Off on Concrete Preservation on Alcatraz

It’s the Most Wonderful Time of the Year

Not only do the kids go back to school, it’s the perfect time of year to propagate your favorite roses from cuttings!


Tapping into the wealth of knowledge from other volunteers on Alcatraz, we found out that a bird docent has a skilled hand at propagating heirloom roses by cuttings. Karen Vandergrift willingly offered to demonstrate her knack.

Karen taking a cutting from 'Bardou Job', our famous Alcatraz rose. Photo by Shelagh Fritz

Karen taking a cutting from ‘Bardou Job’, our famous Alcatraz rose. Photo by Shelagh Fritz

To start, after the rose has bloomed and before the rose hip has started to form, a cutting should be taken down to the fourth leaflet, and cut the stem ½” above the bud.


A rose hip beginning to form under the faded rose bloom. Photo by Shelagh Fritz

A rose hip beginning to form under the faded rose bloom. Photo by Shelagh Fritz

Next, pull off the leaves from the lower two buds and trim off any buds or blooms still remaining on the cutting.


Then, with sharp pruners, cut the top half of the leaves off. This will reduce the surface area that will draw moisture out of the plant.


After that is done, lightly scrape off the layer of stem down to expose the cambium that is on bottom 2” of the stem. Dip the cutting in root hormone.


Using a clean one-gallon pot, stick the cuttings in moist soil, we used our Alcatraz compost, but a potting soil mix would be fine. We put three cuttings in one pot, so hopefully one of them would take. Karen explained that she likes using a 1-gallon pot so the cutting has ample room to grow and does not need to be disturbed by repotting if it were to be started in a sleeve. She also explained that the 1-gallon pot will not dry out as fast as smaller pots.

Karen pressing the cutting into the soil. Photo by Shelagh Fritz

Karen pressing the cutting into the soil. Photo by Shelagh Fritz

Create a mini-greenhouse by placing skewers in the 1-gallon pot and putting a plastic bag over the skewers. The plastic bag and cutting the leaves stops evapo-transpiration that dries out the soil and the tissue of the cutting. Be sure that the leaves of the cuttings are not touching the sides of the bag as this would cause the leaves to rot. The pots are in our greenhouse, out of direct light.

Creating a mini greenhouse  to reduce evapo-transpiration. Photo by Shelagh Fritz

Creating a mini greenhouse to reduce evapo-transpiration. Photo by Shelagh Fritz

We should have rooted cuttings in 6 weeks. We were instructed to water a little bit in one week – and mostly lift up the pots to see if they are light, then they need water.


If no growth is obvious in 3 months, then we’ll try again!

Posted in Gardens of Alcatraz, Plants, Volunteers | Tagged , | Comments Off on It’s the Most Wonderful Time of the Year

Eight Actions You Can Take to help Save the Soil

Help save the soil you wonder? Are we not in drought? Should we not be saving water instead?

I wondered these same questions until I listened to Dr. Stephen Andrews, a soil scientist and professor at U.C. Berkeley. Stating the fact that California is now the driest since 1580 was enough to scare everyone in the room. California depends on water from snowmelt in the Sierra Nevada that slowly melts over the summer months. The snowpack gets replenished during the winter. Without a reliable winter to bring moisture, there is more at stake than just a lack of water.

Another fact –  Just 1 teaspoon of forest soil can contain 10 billion bacteria! Wow! And of the 10 billion, we hardly know anything about them.

Another fact – California has 15.5% of rare soil types and 104 of endangered soils in the USA.

The loss of a soil series is a bigger problem than losing an endangered animal. As Dr. Andrews explained – when you lose a soil, you lose the entire community of organisms supported by it. There is so much we do not know about the ground beneath our feet, that we are not even aware of what we are losing. To further open our minds, Dr. Andrews pointed out the Clean Air Act protects the air, the Clean Water Act protects the water, but there is no Clean Soil Act – very astonishing considering the soil is what we depend on for our food.

So what can the average person do?

1. Lose the Lawn

Ask yourself ‘What is your lawn doing for you?’ There are plenty of low-water lawns to choose from now, check out ‘No Mow Fescue’ or a Delta bluegrass blend.

2. Water Deeply

Two-thirds of a plant’s biomass is underground so getting water to the roots is vital. A deep watering accommodates plants as they grow over time. Water emitters need to be moved as the plant grows to encourage proper root development. If you have a tiny emitter right at the base of tree and never move it, the roots will have no reason to grow further and anchor the tree.

Move emitters further from the plant as it grows to encourage root growth. Photo by Shelagh Fritz

Move emitters further from the plant as it grows to encourage root growth. Photo by Shelagh Fritz

3. Upgrade your Irrigation System

New systems have many programs that you can set, including ‘wet weather sensors’. Be sure to group plants with similar water needs.

4. Capture Every Drop

Keep every drop in your yard, make it your goal to not send any runoff to the street. Capture, re-use and filter your water. Create a water garden, install a water catchment or consider using your grey water to water landscape plants. Be sure to use bio-degradable soap and alternate the landscape plants you are watering. On average 14 000 gallons of water falls onto a rooftop during the rainy season – this stored water could be a source of water during a fire or for an earthquake. The water tanks alongside a house can help moderate the temperature of the home as well – keeping it cooler in the summer and warmer during the winter.

5. Plant Water Wise Plants

The Bay Friendly Coalition provides a list of recommended plants for the Bay Area. Most nurseries will be able to help you choose wisely. Another tip – purchase smaller sized container plants – 1 gallon instead of 5 gallons, 4″ pot instead of 1 gallon. The smaller sized plants will require less water to get established and be under less stress.

6. Skip the Fertilizing

Fertilizing encourages plants to grow – but this new growth needs water. Feed your plants with compost. The nutrients will become available as the compost breaks down naturally.

7. Compost, compost, compost!

Use compost instead of fertilizer. Fertilizer contains salt, which is harmful to soil bacteria and burns plant’s roots. When the soil bacteria is stressed, disease has a chance to settle in. Compost is natural and will decompose over time.

8. Mulch

Mulch is a permanent cover over the soil and can be done in layers to conserve moisture in the soil. The mulch controls weeds and moderates the soil temperatures so the plants’ roots and the soil bacteria have a happier home.

Below is a diagram of what a mulch layer looks like. The larger particles in the top layers will decompose as a new layer is added each year, thereby becoming the layering underneath.

Mulch layer to conserve soil moisture and to moderate soil temperatures.

Mulch layer to conserve soil moisture and to moderate soil temperatures.

Posted in Gardens of Alcatraz, Plants, Sustainability, Weather | Comments Off on Eight Actions You Can Take to help Save the Soil

The Official Flower of San Francisco

Did you know the Dahlia is the official flower of San Francisco?

Dahlia 'Kaiser Wilhelm'. Photo by Shelagh Fritz

Dahlia ‘Kaiser Wilhelm’. Photo by Shelagh Fritz

On October 4, 1926, the San Francisco Board of Supervisors took a vote and animously decided that the Dahlia best represented their city.


From the San Francisco Dahlia Society website, the proclamation reads:


“WHEREAS, the Dahlia has reached its highest perfection in and about San Francisco, and because Dahlias originated in San Francisco are grown in gardens all over the world; and


WHEREAS, the Dahlia partakes essentially of the character of our beloved city, in birth, breeding and habit, for it was originally Mexican, carried thence to Spain, to France and England in turn, being changed in the process from a simple daisy-like wild flower to a cosmopolitan beauty. It has come back to San Francisco like the sophisticated world traveler it is, to find its favorite home here, where it thrives in the cool summers and the moist air of our fog-swept, sandy gardens by the sea;


WHEREAS, it is a robust flower, generous and able to thrive in any reasonable soil, so long as it is not too dry, and has the primitive strength of our pioneer ancestors, together with the gayety and color that no other city nor flower can hope to equal, going, like our artists and poets, to carry color and beauty into far climes, but blooming best in our own gardens out of doors in our cool even climates;


WHEREAS, in its versatility, its beauty, its infinite variety of color and form, it is the very symbol of San Francisco life and of the spirit of her people; therefore, be it

RESOLVED, That the Dahlia be and it is here designated the official flower of San Francisco.”


The Medical Officer and his wife, Mrs. Casey, with their dahlias outside of their Officers' Row home. Photo courtesy of J. Babyak, 1961ca

The Medical Officer and his wife, Mrs. Casey, with their dahlias outside of their Officers’ Row home. Photo courtesy of J. Babyak, 1961ca

The reasons the Dahlia was chosen in 1926 still hold true today – San Francisco is still a world-class city – still innovating, has spirit and still has foggy, cool summers.


Since the 1920’s, dahlias have had a dedicated plot near the Conservatory of Flowers and are an attraction for locals and visitors throughout the summer. With dahlias being so popular, perhaps this is why the residents of Alcatraz began to grow them. Our small collection consists of heirlooms from the 1880’s through the 1940s. The flowers are just beginning to bloom – time to take in this history within history on a tiny island.

Posted in Gardens of Alcatraz, History, Plants | Comments Off on The Official Flower of San Francisco

Drought conditions and what the Gardens of Alcatraz is Doing

California has traditionally gone through cycles of drought and it was an important factor when the Alcatraz Historic Gardens project began in 2003. Restoring an island full of plants did not make much sense if there was no fresh water to care for the rehabilitated gardens.

From the early days of the preservation, there were many common sense things that were done. The simple actions of designing drought tolerant gardens and timing the planting for the winter rains were easy enough to work with. There is such a wide variety of plants that can tolerate and even thrive with little water, that this was never a hindrance to the revival of the gardens. In fact, with now over ten years of first-hand experience on the island, we have built up a list of ‘Alcatraz tested’ plants that we provide on our website.

With rain collection being a known historic occurrence on the island, obtaining approval to once again collect rain water was straightforward enough – again, this had been always been in the garden work plan. However, despite filling the 12 000 gallon catchment to capacity each year, the shortage of rainfall is not saturating the soil. This means that the gardens begin the dry season already thirsty. For the past three years, we have begun to use our stored water in the early spring, instead of months later in the summer.

We have officially entered our fourth year of drought and we wanted to be pro-active and conserve where we can. This year we installed drip irrigation to save water by watering directly to the plants, avoiding overhead hand watering. So far, the rose terrace, Officers’ Row, and two sections of the Prisoner Gardens are on a drip line. We also installed a drip line to establish the native sedge lawn in front of the cellhouse. Once the historic lawn is established, two inches of water are required each summer month – a huge saving from the needed one inch per week for the typical turf grass. The irrigation in each garden area is divided into zones, so we can water sunny areas more, and the shaded corners less often. We have also attached inexpensive water meters to each of the hose pipes to keep track of how many gallons are being used on each garden area.

New irrigation with drip emitters in the Rose Terrace. Photo by Shelagh Fritz

New irrigation with drip emitters in the Rose Terrace. Photo by Shelagh Fritz

This year we also are using fine wood mulch to conserve soil moisture. Mulch was not used historically, but cultivated soil was the historic look. Now, we opt for a more permaculture ‘no-till’ approach with fine ¼” mulch on top. The no-till improves the health of the soil, and the mulch will conserve moisture in the soil. The wood chips will eventually decompose, adding to the organic matter in the soil.

Officers' Row mulched with fine wood chips. Photo by Shelagh Fritz

Officers’ Row mulched with fine wood chips. Photo by Shelagh Fritz

Another water saving tip is to use perennials and not annuals. The majority of the garden plants are perennials. Perennials are better suited with typically deeper roots that can withstand dry conditions. Aside from the recent lawn planting, our last major planting was back in 2010. The perennials are now established and can tolerate drier soil. If you ever try to pull out a native California plant versus a non-native weed, the native will put up a fight while the non-native will easily pull right out.

As the summer continues, we may opt to not plant some of the beds which typically would be planted with annuals. For example, the raised beds in front of the greenhouse have been planted with spring and summer bulbs like cape tulip, Dutch iris and gladiolus followed by summer annuals. This year, we will likely omit planting the annuals and leave the raised beds fallow instead.

Raised beds that may be left furloughed for the summer months. Photo by Shelagh Fritz

Raised beds that may be left furloughed for the summer months. Photo by Shelagh Fritz

As our drought continues, I am seeing more lawns being ripped out and replaced with drought tolerant options, even artificial turf. A trip to see our gardens is well worth it to get ideas for your own backyard.


Posted in Gardens of Alcatraz, Plants, Sustainability, Weather | Tagged , | Comments Off on Drought conditions and what the Gardens of Alcatraz is Doing

A crime scene on Alcatraz

Seabird nesting season is in full force on Alcatraz. This wonderful time of the year is a rare chance to see many of the Bay Area’s seabirds nesting and raising their young. In numbers (and in volume) are the Western gulls. Last year they counted in at around 2000 pairs.


However, their arrival always comes with a bit of apprehension. The gulls of course need material to make nests and must also claim territory. Both of these tasks mean that plants are torn up and shredded, and all too often these are garden plants!


We have come to expect a bit of damage but with the native grass, Carex praegracilis, lawn that was planted with plugs we were a bit nervous if the plugs would take root and be strong enough to withstanding the tugging by gulls.


The plugs were planted at the beginning of November when the rains would hopefully start. While we had some showers we had to supplement with hand watering too from our rainwater catchment. About 1/3 of the lawn was planted and now 5 months along, the plugs have started to send out stolons and are spreading.


On a recent sunny morning, while checking the gardens over, I noticed a puzzling crime scene – the grasses were being shorn off close to their bases.


Carex plugs being nibbled to their bases. Photo by Shelagh Fritz

Carex plugs being nibbled to their bases. Photo by Shelagh Fritz

Guilty by past behavior, I immediately suspected the gulls. But, the telltale sign of shredded vegetation was not present. In fact, the missing tops of the grasses were actually gone! What could this be? We don’t have deer or rabbits and yet the grass looked ‘nibbled’.


Examining the scene closer, I spied the ‘evidence’ left behind – droppings. Sure enough Canada geese had found our lawn. There are maybe 3 pairs of geese on the island and they were making our lawn their morning buffet.


Canada goose 'evidence'. Photo by Shelagh Fritz

Canada goose ‘evidence’. Photo by Shelagh Fritz

For all of our planning and thinking of possible ‘what could go wrong scenarios’, we had overlooked the population of geese and their liking of grass.


Luckily, few plugs have been pulled out, the geese are proving to be more grazers, and hopefully the plugs will continue to grow. Mowing actually helps grasses get thicker and encourages them to send out more stolons.


The lawn is slowly being ‘mown’ from left to right, but at least the plugs are being fertilized too.

The native sedge lawn being 'mown' by Canada geese. Photo by Shelagh Fritz

The native sedge lawn being ‘mown’ by Canada geese. Photo by Shelagh Fritz


With the mandated 25% cut in water usage in California, I’m so relieved we choose to have a native sedge replicate the look of a lawn. Our ‘lawn’ will be low maintenance and will only require 2” of water per month to stay relatively green throughout the summer months.


As Alcatraz is a destination, I’m hoping that visitors will take notice of our drought tolerant lawn and ask questions. The lawn will also be a topic on our garden tours and offered as an alternative.

Posted in Gardens of Alcatraz, Plants, Rehabilitation, Wildlife | Comments Off on A crime scene on Alcatraz

Gardeners in a Candy shop

Technically this past Monday was a workday but instead of being on our beloved island, we had planned to go to the Dr. Herman Schwartz garden – Bolinas Botanical Garden – to take cuttings of succulents to add to our own Alcatraz garden. The trip hardly seemed like ‘work’.

Marin-Bolinas Botanical Garden started by Dr. Herman Schwartz.

Marin-Bolinas Botanical Garden started by Dr. Herman Schwartz.

The Marin-Bolinas Botanical garden was started by Dr. Herman Schwartz and contains over 2000 species. A YouTube video of an interview captures him well as he sits in one of his greenhouse. An early interest in plants and animals started him on his lifelong passion for plants. Although Dr. Schwartz passed away in January 2008, his passion lives on.


The trip was a privilege, arranged by a common friend of Dr. Schwartz’s son, David. I had only been once before in 2010 with Brian Kemble, curator for the gardens. Just like then, I was astounded by the rich variety of succulents and euphorbias. The garden is similar to Alcatraz’s gardens in a way – both are very unexpected in an unlikely place. Both have plants gathered from all over the world, in Dr. Schwartz’s interview, he says “I don’t have to travel anymore because I can transport myself to where I found them”.


As we stepped from the car, many succulents were in full bloom, and the sheer size of the garden hit us. Like kids in a candy store, we almost didn’t know where to start first! We could barely walk 5 feet without stopping and spotting a new plant, we soon had our bag full and we realized we didn’t bring enough bags. Memories of trick or treating came back – a full bag and still more stops to go. Luckily the car was nearby.


Blue Senecio rambling amongst grey Orbiculata. Shelagh Fritz photo

Blue Senecio rambling amongst grey Orbiculata. Shelagh Fritz photo

It was fun to point out the plants that I had collected back in 2010 to the staff gardener and intern. All of the plants are thriving on the island – Cotyledon orbiculata (gray and green forms), Echeveria pulvinata, and Aeonium cuneatum to name a few.


We did find new Kalanchoe, a new red blooming Orbiculata, a blue Senecio, Dudleya, Agave victoria-reginae, of which there was only one so we did not select it but we will soon be sourcing it. Without Brian on this visit, I will soon be in touch with him for the correct names of the cuttings we took. When these are added to the Alcatraz gardens, we will also update our plant collection database and will proudly note where the cuttings came from.


Agave victoria-reginae. Photo by Shelagh Fritz.

Agave victoria-reginae. Photo by Shelagh Fritz.

Walking in this garden was an honour, and just like our own Alcatraz gardens, the presence of past gardeners was felt. With respect, we took our cuttings, and I hope our joy of finding new treasures and our delight at spending time in this garden could be seen by Dr. Schwartz.


Posted in Plants | Comments Off on Gardeners in a Candy shop

Chilly Temperatures

I hate to complain about our winter temperatures while other parts of the United States hunker inside from cold weather warnings BUT, it was rather chilly for our succulents and tender plants on the island last week. Seldom do we receive a frost in San Francisco, let alone on Alcatraz, but the low temperatures and wind did cause minor damage to our Aeonium arboreum, Zantedeshia aethiopica (calla lily), and Tropaeolum (nasturtium).


Cold damage to Aeonium arboreum. Photo by Shelagh Fritz

Cold damage to Aeonium arboreum. Photo by Shelagh Fritz

It is difficult to have an exact temperature that the damage occurred on these plants, but Aeonium can tolerate freezing for a half a day to a day before the plant would actually die. Our plants look like they are all nodding their heads and will make a strong recovery.

As for the calla lilies, the leaves are mottled green and are turning mushy, resembling spinach that has been frozen in the back drawer of a refrigerator. The tough rhizomes will send up new leaves, and might just have a later bloom than normal. The nasturtiums we ended up removing as the leaves looked very tattered and were turning yellow. There are enough seeds dormant in the soil from years of these annuals setting seed, so they will replace themselves soon enough.


Damage to emerging Calla leaves. Photo by Shelagh Fritz

Damage to emerging Calla leaves. Photo by Shelagh Fritz

Damage to Nasturtium leaves. Photo by Shelagh Fritz

Damage to Nasturtium leaves. Photo by Shelagh Fritz













An interesting fact about cold winter temperatures is that in 1933, the California Horticulture Society began because of an “in the winter of 1933 an unusually frigid air mass withered gardens in the greater San Francisco Bay Area. A small group of concerned gardeners met to compare plant survival information, and they became the nucleus of the present Society.” – Which also happens to be the oldest plant association in California!


It’s always interesting to compare notes with other neighbour gardeners to see how their garden fared a cold snap – you may even pick up a few new hardy plants.

Posted in Uncategorized | Comments Off on Chilly Temperatures