2005 ASLA Student Awards

Vivero Metropolitano: A Productive Nursery Landscape for Monterrey, Mexico
Kate Kennen, Student ASLA

Harvard Design School
Advisors: Lee Cott, FAIA and Mario Schjetnan, FASLA

Vivero Metropolitano creates a regional nursery for the city of Monterrey Mexico along the Santa Caterina River, providing an ecological, social and economic landscape for urban revitalization.

Location
Monterrey is located in the northeast region Mexico and is Mexico's third largest city with five million people located along two seasonal flooding rivers, the Santa Catarina and the Topochico. The intensity of rapid urbanization, as well as a lack of understanding and sensibility for its setting, have allowed its rivers to be ignored as ecological resources for water, plants and fauna, and as possible public open space corridors in this semi-desert landscape. The rivers have been channelized with concrete, and little ecological function remains. The site investigated is a 1 km long riverbed parcel within the 100 year floodplain of the Santa Caterina. Although the site is only 1km long, the intent is to create a replicable strategy that could be used along other parts of Monterrey’s rivers.

Concept
The concept is to create a productive landscape, one that not only provides recreational benefits but also creates ecological and economic enhancement as well. Large scale public landscapes traditionally demand intense maintenance regimes, draining public coffers while dumping tons of nitrogen fertilizer and water onto lawns and plantings. Vivero Metropolitano presents an alternate public landscape model: a productive openspace where daily park maintenance is one and the same with the nursery production process. A public landscape is created through the ongoing function of leased land to private nursery growers. The landscape is designed to interweave public recreation functions and nursery operations, all while producing native plants species for sale. The combination generates economic revenues, habitat enhancement, and social benefit.

Regional Trends
Monterrey will host an international Cultural Forum in 2007. New Forum program developments will require a minimum of 3,800 trees and 310,000 bedding plants; current growers, however, do not have capacity to produce these plant materials. In 1km of the Vivero Metropolitano nursery, [less than 4 miles away from the Forum site] 284,000 bedding plants & 27,000 5 gal. container palms could be produced. [See Dwgs 1&2]

Through regional analysis, it was also discovered that universally accepted global warming predictions expect that Monterrey’s climate will increase significantly by 3 degrees Celsius over the next 50 years. Studies have shown that currently, US border towns with the same ecology as their neighboring Mexican border towns are 3 degrees cooler than the Mexican towns 2 miles away. This has been attributed to the increased amount of vegetation in the US towns, providing transpiration and passive cooling. An addition of plant materials to the Monterrey area could help to reduce this warming trend. [See Dwgs 1&2]

The Nursery Landscape
A Nursery landscape that integrates both recreational functions and nursery operations was conceived. The Santa Caterina riverbed provides and ideal nursery location since the most important nursery inputs [good soil, water, and availability of labor] are present.

Plants for propagation were chosen using three criteria: 1) Plants had to be xerophytes and drought tolerant 2) native and 3) easy to propagate. Species naturally grouped themselves into 4 categories and each group has its own set of propagation requirements. The following groups of plants lead to the design of 4 flexible propagation systems. [15 & 16- See Plant List]

1) Herbacious Bedding Plants: Ex. Salvia, Lantana = Bedding Plant Propagation System
2) Woody perennials: Ex. Palms & Yuccas = Woody Plant Container Propagation System
3) Succulents: Ex. Prickly Pear, Daisylirion = Succulent Plant Propagation System
4) Flood tolerant Woody Plants: Ex: Mesquite and Montezuma cypress = Woody Plant In-ground Propagation System

Water Systems
Water, a scarce resource in the Monterrey area, is critical for propagation of all of these plant groups. A water harvesting, storage, irrigation and cleansing system was designed to function for both the nursery and recreational activities. [See Dwg 14] First, water is diverted through a check dam to enter storage canals on the south side of river. The storage canals are shaded by the south riverbank and kept narrow and deep to limit evaporation. Water is then pumped from these canals and used for spray or gravity fed irrigation. The topography is sloped towards the north so that excess water runoff is collected in intermediate retention/ wetland areas before slowly filtering into river, eliminating pollutants. The main river channel maintains base flow for habitat and is recontoured to create a pool and riffle sequence for fish. New topography allows for base, peak flow and 10 year floods to be accommodated without having to move any plants. Only in 100 yr flood events would container plants need to be moved.

Recreation Systems
A linked network of recreation trails bring users from surrounding neighborhoods into the site. [See Dwg 14] Multi-modal paths on both sides of the nursery keep public separated from operations while also enjoying the benefit of this richly textured landscape. Paths are integrated into the edge on the north side and along the canal on the south side. Water separates the public system from the private system- a few gates secure the nursery at night along the crossings of the water. The path shape responds to the smaller shape of herringbone mounds and sneaks within and around these landforms creating entry points (allowing to manipulate topography and slope)

A regional entrance to this new nursery landscape is within an existing large park to the south and includes a visitors center and parking area. The parking area doubles as a water harvesting site. Demonstration gardens are also included to educate users about the propagation of native plants and the endangered animal species they support.

Plant Propagation Systems
Nursery operations are organized around the nursery sales center located on the north side of the site. [See Dwg 3] Currently utilizing and existing vacant parcel outside of the floodplain, the center has enough maintenance and shipping space to support 4 km of riverbed nursery. Building roofs are sloped to collect water runoff and provide platforms for solar panels. Operational roads connect the entire nursery site. The roads were designed for efficiency, creating a maximum walking distance of 50 M from any propagation bed to a road.

The 4 types of propagation systems were designed using a common dimensional module to accommodate changes in plant production quantities over time. The 4 interchangeable systems are described below.

Bedding Plant Propagation System [See Dwgs 7& 8]
For non-greenhouse bedding plant propagation, sun tunnels must be used to protect plants. The system designed for Vivero Metropolitano utilizes terraces to protect 1 meter x 10 meter planting beds. Overhead irrigation lines emerge out of 1 meter height terraces, and double as frames; the frames support sun fabric to protect the plants.

Woody Container Propagation System [See Dwgs 7& 8]
Temporary asymetircal shade structures [aluminum with mesh] are designed over propagation areas with container plants underneath. The shade structures are designed with a pulley system to rotate during the day to provide sun and wind screening, and they also carry irrigation lines. These lightweight structures can also be used as recreational shade structures and can be moved in the even of a 100 yr flood.

Succulent Plant Propagation System [See Dwgs 9&10]
This system is designed using passive water harvesting irrigation on the edges of the river bed.
Succulent propagation areas take on two forms- herringbone mounds and linear mounds.

Herringbone mounds
Herringbone mounds are used in areas that do not receive significant directional force during flood events. Piles of construction debris are dumped, and dressed with topsoil and erosion control fabric. A nitrogen fixing legume is seeded on the mounds. The shape of these mounds collects water on the back side; succulent plants are placed at the tops of the piles for propagation.

Linear mounds
Linear mounds are used on the highly eroded river banks that receive significant force during flood events. Concrete channels currently exist in these areas. The concrete is ground up and used for basis of these long narrow berms. Also constructed at eh scale of the truck to maximize efficiency, the berms are reinforced with erosion control system and dressed with topsoil for legume and succulent planting.
Both of the systems catch runoff storm water from adjacent roadways, filter it, and slow it down before it reaches the river. Over time, mounds catch wind-blown and bird-dispersed seeds to help naturally reestablish the river’s edge.

Phasing & Vegetative Sprawl
The intent is for the nursery to take on a life of its own, spreading native seeds and plants within the urban landscape. [See Dwgs 12 & 11] In Phase one, the four interchangeable plant propagation systems are initiated. In about 8 years, Phase two will begin when the Monterrey government finishes building a damn that will limit large flood events to peak 10yr. flows. At this time, woody plants can be directly planted within the riverbed. If nursery operations cease at some point in the future, Phase 3 commences. This is the beginning of a sprawl-like native landscape that takes over the river, providing a functioning ecology and new generator of future urban form.