City officials love to cut ribbons at park openings. However, what happens after the ribbon cutting determines the success or failure of urban parks. Without proper care, even beautifully designed and installed landscapes will fail. Maintaining a habitat park presents unique challenges. After opening the nature park in South Pasadena—Arroyo Seco Woodland and Wildlife Park—the city was confronted with this task, and the weeds were getting the upper hand.
The challenges of caring for habitat
Habitat parks are different from most city parks, which usually consist of ornamental shrubs and trees growing in expanses of turf grass. City crews mow and edge weekly, control weeds as needed, and occasionally prune. Irrigation schedules keep the grass green and the shrubs and trees alive.
Our nature park is a different story. For one thing, there is no lawn; for another, there is no automatic irrigation system. Most importantly, the maintenance crew is unfamiliar with native plants. Workers often can’t distinguish between plants that should be there and those that shouldn’t. This is especially problematic since, in good habitat, seedlings of native plants should be allowed to spread throughout the area, and seedlings of non-natives must be removed before they produce flowers and seeds of their own.
Native plants also have different horticultural needs than most ornamentals. The native plants in our nature park are adapted to a mediterranean climate: hot, dry summers and cool, wet winters. Once established, these plants do not need, or want, regular water through the summer. This is just one of the important differences in plant care between native habitat plants and common ornamentals.
Habitat is messy
Nature parks provide habitat for birds, butterflies, lizards, coyotes, and other animals that can survive in our cities. Good habitat is messy. Dead plant material is essential for insects, and insects are essential for birds. Yet, city parks are usually structured and neat. The desire to remove all dead and dying plant matter is ingrained in city officials, landscapers, and even the public.
In addition, habitat is a system in constant flux. Not only do plants undergo seasonal and life-cycle changes, they also spread by seed, popping up here and dying back there. Annuals appear where their seeds are carried and take hold, and trees and shrubs materialize where birds and squirrels bury or drop their acorns and berries. Again, this difference can present a problem for gardeners who are trained to maintain a controlled, traditional landscape.
However, the importance of removing weeds cannot be overstated. Left alone, aggressive non-native weeds will overwhelm native plants, making it especially difficult for desirable seedlings to take hold. So gardeners must be able to distinguish native from non-native plants during both seedling and mature stages. They must take care to remove weeds and avoid damage to native seedlings. This is slow, deliberate work, unlike the broad-brush approach applied to lawn-dominated parks. For these reasons, it is challenging for cities to maintain habitat parks.
Friends of South Pasadena Nature Park
Within six months of opening the South Pasadena nature park, the recently cleared weeds made an impressive comeback. In response, I initiated a volunteer stewardship program, Friends of South Pasadena Nature Park (FONP). We have been working in this four-acre park for the past twelve years.
Our group is very informal. I post announcements on a Facebook page and one or two websites to publicize the monthly Saturday morning cleanups. Approximately 100 people receive email notifications. A small group of “regulars”—a half-dozen or so—comes to these cleanups. Larger groups of scouts, high school and college students, garden club members, and others participate sporadically, as well. In addition, three or four long-term park stewards work on Wednesday mornings throughout the year. We do not formally announce the Wednesday weeding sessions, though everyone is welcome.
It has taken years—and we still have much work to do—but with city support, our small team of volunteers is gradually improving conditions in the park.
Weed and plant
I would like to share some of our strategies that might help other volunteer groups. When I began working in the park, I thought the best approach would be to control weeds and then plant natives. This strategy, however, proved to be surprisingly ineffective. Simply put, we were unable to control the weeds. We have found that it is better to begin with small, manageable areas. Once we have planted natives, we continue to weed diligently. As the young plants become established, fewer weeds make a comeback; however, we are careful to keep these planted areas as weed-free as possible.
While one can plant in Southern California throughout the year, we are most successful when we do so in early winter. Temperatures are cooler, and the new plants get some of the water they need from rainfall. Nevertheless, we hand-water young plants as needed for the first year or two.
Then weed some more
Weeds grow best in soil that has been disturbed. This means that each time we pull a weed or use a hoe, we remove the offending organism and create conditions for more to grow. Our approach has been to weed with minimal soil disturbance by removing weeds when they are just getting started—so timing is critical. This practice also eliminates weeds before they go to seed, and has been especially helpful in controlling castor bean, horehound, and other weedy perennials.
Annuals are difficult because they emerge all at once and go to seed quickly. Last year, following a rainy winter, London rocket and weedy annual grasses got way ahead of us. Although we hand-weeded early in the year, sections of the park were still choked with weeds. We used a string trimmer on the dead annuals and raked out as much plant matter and seeds as possible. We then spread a four-inch-thick layer of mulch from urban green waste.
Although it is tempting to leave the spent annuals in place—because, after all, they have already spread much of their seed—we have found that it is easier to see and remove new emerging weeds when they are not hidden. The native plants also do better when they are not buried beneath the dried thatch. Plus, the park looks loved and cared for after we clear the weeds and apply mulch.
We select plants that may have grown naturally in this area, taking into account the current conditions. The meandering, intermittently dry riverbed that was once the Arroyo Seco is now a concrete flood-control channel. So, although the natural Arroyo Seco habitat probably included more willows and other riparian plants, we choose plants that grow in the drier conditions of Southern California coastal sage scrub and oak-walnut woodland. We are also careful to protect native plants that pre-date park installation. These include golden currant (Ribes aureum), fiddleneck (Amsinckia douglasiana), sacred datura (Datura wrightii), Southern California black walnut (Juglans californica), coast live oak (Quercus agrifolia), and western sycamore (Platanus racemosa), among others.
Angelenos are accustomed to gardens that bloom brightly throughout the year. Some fail to see the beauty of native plants and their wonderful adaptations to our mild but hot and dry climate. Although I love the burnt orange color of dried buckwheat flowers, others are not so sure. So we include plants that bloom during summer and fall when most everything else has gone dormant or slowed down. Wild sunflowers give the park a cheerful look in late spring and summer, and are appreciated by many birds and mammals. California fuchsias (Epilobium spp. syn. Zauschneria spp.), often visited by hummingbirds, add striking red flowers from late summer through fall.
For the past 12 years, our volunteer group has done most of the work to maintain and develop the park. We are making great progress in controlling weeds and establishing natives as we move from section to section. However, none of this would have been possible without the backing of our city.
Over the years, several members of the city council have strongly supported the park and our volunteer efforts. They have communicated this to city park workers so that they can help out when maintenance needs are beyond the ability of volunteers.
One example of this city/volunteer coordination is our weed control strategy. Early on, city workers applied herbicides to control weeds. Not only did this go against our efforts to create good habitat, we lost new native seedlings to herbicide drift and accidental spraying. And some of the loss was due to the simple fact that workers were unfamiliar with native plants. We discussed the problem with city staff and they agreed to only use herbicides to control weeds that we could not easily remove by hand. City workers now spray to control poison oak that is growing close to paths, and they use a cut-and-spray method to eliminate tree of heaven (Ailanthus altissima). Being able to work with the city has been crucial to the success of our long-term efforts.
Reaching the public
Getting the word out has been one of the biggest challenges that I have faced as the organizer of FONP. Our park is in an unfrequented location. Although an attractive river rock sign marks the entrance to the park, few people notice it on the busy street at the city border. It is truly a hidden gem.
Marketing our park and our stewardship program is probably one of my weakest attributes. But I created a blog, a website, and a Facebook page (see below for details) to announce park cleanups and to report on park conditions. We also hold educational events in the park to involve the community. We collaborate with local teachers, students, scouts, and city program managers.
Though we would like more people to know about the park, we do see a steady stream of joggers and walkers when we are working. We hand out business cards with contact information about volunteer opportunities.
The challenges we face in our nature park are common to many urban areas. Graffiti, vandalism, littering, and even a recent brush fire reflect problems with homelessness, gang activity, unsupervised youth, and inadequate civic pride. These problems are likely to continue in our secluded and unfenced park. The city responds quickly to our reports of tagging, homeless encampments, and vandalism. Nevertheless, these conditions are unlikely to change until society deals with the underlying causes.
We have made much progress in establishing areas dominated by native plants, yet the weeds remain a major threat. I hope that perseverance will eventually reduce the amount of time needed to control them; however, the park will require ongoing care.
We continue to work to increase awareness and use of the park. Recently, the city began a new project to build a bicycle and pedestrian path along a portion of the Arroyo Seco that goes through the nature park. This is an exciting development that will likely bring in many new people.
Although it may seem disappointing that urban habitat parks can never truly be self-sustaining, this shouldn’t be seen as a shortcoming. There is real value in our stewardship program: It is educational, and it encourages civic responsibility and pride. I know that over the past 12 years I have made lasting friendships and learned a great deal by donating my time to this worthwhile effort. The ribbon cutting was just the beginning—it is the journey that we should value.
For more information about the Arroyo Seco Woodland and Wildlife Park and how you can contribute to its care, explore these resources:
For more information on the creation of the park read Native by Design: Community Involvement in the Creation and Stewardship of a Nature Park, in Fremontia, a publication of the California Native Plant Society.