These pictures are from the first day we started planting on the living wall. We had brought up this cart of various plants to try out. There was some Asian Jasmine, Shamrock, Bamboo and a few others.
Before we were able to put new plants in we had to disassemble the old wall, tear out the old plants and collect the old soil for reuse.
The plants had to be taken out of the pots and the root balls had to be broken up and loosened so that they would fit comfortably in the wall modules. We collected most of the soil from the pots for reuse.
After we brought all the plants up, took down the old modules and disassembled them and divided up the plants, we only ended up changing out two of the modules that day.
The planting party last on the morning of May 5th was a whirlwind of planting, pizza. A few more students from the BLA and MLA programs joined us to help us plant hundreds of succulents on the irrigated green roof, felt module green wall and the non-irrigated prairie green roof. I worked on the irrigated green roof, we planted various succulents (mostly sedums) and marked down where each grouping was placed on the diagram. We tried to pair up plants that would work together aesthetically and not crowd the existing plants out.
We checked up on the green wall we had planted previously a few of the plants were looking a little brown, but some of them were doing quite well.
One day when we could not go onto the roof due to weather, we each researched succulents that we thought would work well on the succulent/xeric roof garden. It was an educational experience, as I really did not know much about succulents beforehand. We were given a list of plants to look up to research their hardiness. These plants included:
Sedum reflexum f. cristatum
Sedum moranense subsp. grandiflorum
Sedum kamtschaticum subsp. ellacombianum
Delosperma ‘Mesa Verde’
In addition to these plants, we were to suggest additional succulents to add to the list of potential species that would grow on the roof. Everyone suggested a variety of interesting plants to look up. I suggested Graptosedum ‘Vera Higgins,’ Sedum palmeri, and Sedum potosinum based on their known ability to grow within Central and South Texas.
On a green roof, we learned that there are a variety of different factors that affect the hardiness of plants. The main opposing climatic conditions consist of high heat and humidity during the summer and freezing temperatures in the winter. Previous green roof trials failed to meet an occasional freeze into the lower temperatures. With this in mind, it is important to research plants that can withstand the lower temperatures at least moderately, so that they will not die every few years when the temperature gets that low.
Ultimately, we planted a Delosperma species as well as several other sedums as mentioned in the previous posts. Researching plant species ‘extends the horizons’ and challenges the perception on what a truly defines a green roof. As research continues, more knowledge on the durability of these plants on will increase the variety and frequency of efficient greenroofs in Texas.
Sedums are the staple green roof plant but they’re not very successful in some areas. They are great drought tolerant ground covers since they grow fast and there a lot of different shapes and colors. However, it is said that sedums are not very successful in Texas since some Sedums are not able to withstand the unpredictable Texas weather. This research will helps us determine weather this is true or not. We have a lot of different species to test that will help us determine what kind of Sedums survive under the climate conditions in this area.
The first step was split up into teams since there were three different areas where we were going to install new plants: the green roof, succulent wall, and succulent roof with no irrigation. We were given a list with the names and amount of Sedums assigned to our section, which was the green roof with irrigation. Each module had a plant in center and anything else in the module was growing around it. The first step was to decide which sedums we want to group together, we started out by selecting three different sedums and placing them in groups of three. We also had to record where each sedum was planted and how many where planted in each area. After planting the first group of Sedums we realized that we still had a lot of plugs. We started planting a lot of them in all of the modules and set aside the design part of this project. The most important part at this point was making sure we recorded where everything was planted.
Since we planted sedums in different areas of the green roof with different environmental conditions we have a variety of experiments that were started. These sedums will be monitored to determine their success and this could be very important research for the future of green roofs in Texas. Green roofs are becoming very popular not only because of their look but also because this could highly benefit people in urban areas. In big cities where the majority of people live in apartment buildings green roofs could be their only hope for a garden.
Recently, we received a gracious donation of sedums to test their durability on the green roof. Though it is often stated that sedums would not fair well on green roofs in Texas, they have not been given a fair opportunity to prove themselves. In this next leg of research, Prof. Dvorak plans to research the sustainability of these plant materials.
On Friday, we had an end-of-semester planting party (complete with pizza of course!) The students involved in Prof. Dvorak’s green roof class, Dr. Jeremy Merrill, as well as some additional student volunteers in the landscape architecture program divided up the sedum and perennial species according to their microclimatic and growth needs to distribute to the different gardens on the roof, as well as one of the living walls. Dr. Merrill, Kristal, and I worked on designing and installing the plants in the modules on the Northwest corner of the Langford roof among some of Prof. Dvorak’s previous research is still taking place.
In these modules, some of these plants included:
Sedum spurium ‘Red Carpet’
Sedum ‘Blue Spruce’
Sedum ‘John Creech’
In planting them, we spaced them about 3″-4″ apart and tried to design them in drifts. We tried to make sure that we planted at least three different species in each module with varied heights. We learned how to document the locations of the plants within the modules to ensure that their progress can be monitored.
These sedums will further be monitored on their ability to withstand humidity and the Texas heat as the summer progresses.
May 5, 2016
Today was the last day on the green roof. With volunteers, we divided into three groups: the xeric modules, the living wall, and the modules on the metal walkway. I worked on the modules on the walkway. We cleared everything in the modules we were going to replant, except for some modules that had succulents that had been growing for years.
After clearing them, we checked the list of the plants that were to be planted there and decided on a planting design.
A lot of the plants were sedum species, such as Sedum reflexum ‘Blue Spruce’ and Sedum sexangulare. Delosperma nubigenum was also used. After we planted and watered them, we recorded how many of each plant was in each module, excluding the ones we didn’t touch.
After a semester on the green roof, I feel like I learned a lot. I can take apart and put back together a wall module, adjust the water levels, and which plants do well on a green roof. Also that recording information is crucial to see what works and the progress of the roof. I definitely had fun learning all theses things and I hope the plants we planted will last a long time.
March 22, 2016
Today we continued to replace plants in the wall modules, inserting new ones into empty modules. Some of the grass on the wall was clipped to make it look nicer.
The living wall was finished today. The last plants to go in were sedges, which filled in the last two remaining modules.
After we were done, the water was turned on so we could see which nozzles didn’t work or were letting out too much water for the plants, and to see how the plants were getting water in general. Only two of them didn’t work, but was easily fixed by turning the nozzle to let water run out. We adjusted the ones that put out too much water, which I learned how to do.
Currently, the main portions of the modular green roof consist of two separate gardens: the succulent/xeric garden, and the prairie garden. At the start of the semester, we began to weed the succulent/xeric portions of the modular green roof. While the plants provide an attractive and native take on a traditional roof garden, (as with most plants) it takes a little while for them to establish. Meanwhile, irrigation provided to establish/maintain the garden as well as the low density of the plantings inevitably invited the weeds.
In addition to crab grass, we pulled a total of 453 weeds. Pictured below are some of the species we removed from the modules:
In addition, there was much cilantro from a previous planting that found its way into several of the modules (81 plants in total).
While this is a normal thing to expect for the low density plantings, adding density and lighter irrigation will minimize the weeds in the long term.
On the same day, we seeded several types of succulents and sedums, but many if them did not seem to establish (at least not yet). This being said, we learned that transplanting pre-potted plants or planting plugs is a more reliable way to ensure that new plants flourish. Since then, we have added many more plants to the modules, adding both to the density and appeal of the xeric/succulent garden.
(this happened earlier in the semester when we had just started on the roof)
Before we started planting, we had to do some major weed pulling in the succulent modules. While pulling them, we had to keep a record of the number of each weed we pulled. This excluded the grass, since there was so much of it. Some of them were tricky since they looked similar to the succulents.
It took the whole class to pull and record them. Although recording them took a while, it was important to know that plants could find their way up to the roof and grow there. It was also important to know which plants could grow on their own, even if they were weeds. It was meticulous work, but it paid off and I learned that recording plants, even weeds, is very important and contributes positively to the green roof.
For our next project we worked on one of the green walls. We had to start out by deciding which modules we had to re-do since some had living plant material that just needed to be moved or trimmed and the rest were dead. We had a lot of new plant material to work with for the modules being re-done. Bamboo, asian jasmine, phlox, shamrock, and juniper. Next, we had to decide which location of the wall would work for each plant since not all parts of the wall retained the same amount of water. Not all parts of the wall were under the same climate conditions. The bottom part of the wall had the received less sunlight and retained the most water. However, the top part of the wall received a lot more sunlight and later we realized the irrigation had not been placed correctly so it didn’t receive as much water.
Phlox being separated into two to be installed on the modules
Module ready to be installed on the wall
To change the plants on each module we had to take them down from the wall and remove everything in them. We remove the plants form the modules and poured out the media. We then mixed that media with a scoop of compost and slow-release fertilizer. The first plant to be installed was juniper. At first it was a struggle getting the plant the module since it had a very large root system but after breaking it in half we were able to get it in the module and found an easier way to put the rest inside the module. This required some teamwork since there were several steps to make sure the plants were placed correctly on the module to avoid them from falling out of the module.
Some of the plants only took one week to show the results of how they adapted to their new environment. Three out of the four Junipers installed dried out even though they were not broken into half like the one that survived. The Phlox seem to vary since a few dried out and some are still doing pretty well. The Bamboo and Asian Jasmine are doing great and showed no signs of of stress after being transplanted to the modules, which could indicate that they’ll be successful on the wall. The final step was to fix the irrigation since not each module was receiving the same amount of water.
In this project I learned about the importance of considering the plants environmental preferences when it comes to coming up with a design. We were able to get pretty early results on how some of these plants adapted but that might not necessarily mean that they won’t survive. A lot of plants go through transplant stress before they completely adapt to their new environmental conditions.
In this course we are learning about wall and green roof design, installation, and maintenance. This semester we are trying to see what has worked from previous semesters, what we can improve, and what new things we can try. For the first few weeks of this course we worked on repairing irrigation, doing research on new plants we could use, planting new seeds and plants, and removing a lot of weeds.
One of the first projects I was involved in was fixing the irrigation in wall 2. The main problem was that the water was not reaching the top part of the wall so whatever was growing there dried out. This happened because the main hose was connected to the bottom of the drip irrigation hose. We fixed this by connecting the main hose to a PVC pipe to allow the water to go all the way to the top and then come down through the drip irrigation hose. This allowed the whole wall to receive water.
After fixing the irrigation we started planning and planting new vegetables. Peas and radish seedlings were harvested from bed 1, which is growing different kinds of vegetables and herbs. We chose spots that were empty since whatever was in there previously had already dried out and would allow the peas and radishes to grow successfully with the improved irrigation. We placed the peas in the left end of the wall towards the middle and the radishes towards the right.
Peas and radishes harvested from bed 1
Peas after 6 of being planted
We spent almost 2 days removing weeds before we could move on to planting new succulents. Once we were done with most of the weeding we started planting some new sedums. We placed three in some of the modules where there was only one plant growing in the middle of the module. After that we proceeded to planting Aloe and Frogfruit, Manfreda, and Hechtia seeds.
For our latest project we took one of the modules from bed 3 and took it apart to analyze how everything was growing since this [art pf the greenroof hasn’t had irrigation for about a year. We removed the plants from the module and separated the soil, geotextile, and the roots which had grown under the geotextile. We separated the plants that where growing in the module into two groups, we had iceplant and a grass in this module. We noticed that the grass roots where the ones growing roots under the geotextile to reach the moisture under it and the iceplant roots remained above the geotextile to stay away form that moisture. I recorded the total weight of the ice plant and their roots and did the same for the grass. Some of the things I learned about this project was the importance of recording data like observations, measurements, and taking pictures.
Plants pulled off the module
Separating the geotextile and roots
After a semester filled with exciting new projects and data analysis, the green roof project group took our findings to the American Meteorological Society Conference in New Orleans. During the semester, we scanned through multiple data sets to find any interesting topics … Continue reading