Since 1960, when a green space responsible body was established in Tehran municipality, until 1988, 154 parks were constructed in Tehran city. Most of them were located in affluent neighborhoods and were unevenly distributed. Furthermore, peri-urban forests were managed separately, covering a total land area of 2,937 hectares. Until then, no planned activity concerning promotion, education, research and public participation in the field of urban green space had been done.

Because of the unbalanced development of Tehran city and uncontrolled growth of its population, existing green spaces didn't satisfy the citizens’ needs. Therefore, more parks were needed in order to strengthen human-nature relation, create safe, and accessible areas for different classes of society to spend their leisure time in.

Furthermore, increased number of motorized vehicles, thermogenic instruments as well as plants and factories developing in urban and peri-urban areas, lack of winds, low precipitation and mountains surrounding Tehran city resulted in ever-increasing congestion of pollutants in Tehran. Therefore, development of urban and peri-urban forests was among the priorities in order to mitigate pollution. Another objective of the green belt and peri-urban forests was to prevent uncontrolled expansion of Tehran.

Planning and organizing promotional, educational and research activities were among other priorities on the agenda with the aim of improving abilities and skills of experts and green space involved individuals.

Developing comprehensive planning and formulating strategies in order to achieve sustainable development of Tehran green space and improve environmental condition, have been put on Tehran Parks and Green Space Organization’s agenda since 1988. Key dates in this regard are as follow:

1. Physical development and improvement of parks and urban forests since 1988.
2. Development of educational, promotional, and research activities since 1990.
3. Development of public participation for raising awareness since 2005.
4. Development of green spaces along highways since 1990.
5. Physical development of peri-urban forests since 2003.

It is necessary to mention that along with these five steps, implementation of coordinated and integrated green space activities have been continually on the agenda.

The whole capital of Tehran Parks and Green Space Organization (TPGSO ) belongs to Tehran municipality and TPGSO is entitled to earn income through following ways:

• Delivering consulting and other kinds of professional services to applicants.
• Issuing written authorization for green space restoration in accordance to green space protection and development bill.
• Other means of earning income which are approved by TPGSO commission.

a) Executive measures

- Establishment of over 1,822 neighborhood, local, district, urban, linear, regional and trans-regional parks. Some of these parks were established in more deprived neighborhoods.

- Significant increase in total urban green space cover including parks, greenery of urban access routes, refuges, squares and green spaces patches: urban green space per capita has already reached 15.1 m². According to projections for 2014-2018, two thousands hectares of urban green spaces will be established if suffisant credits are allocated. Urban green space per capita will reach 17.2 m².

- Establishment of about 36,000 hectares of peri-urban forests, added to the green belt.

- Isolation of the mountains located on north side of Tehran to prevent any construction there.

- Execution of the master plan of crude water of Tehran city through restoring 431 rings of wells, 45 streams of aqua ducts, and one spring in order to irrigate Tehran green space, as well as designing and executing 169 projects on water supply and under pressure irrigating systems.

B) Paving the way, capacity building, and side activities

- Training 17,802 experts, technicians, and gardeners by holding 1,330 training courses that aim at promoting a scientific vision towards the development and maintenance of green spaces.

The process of planning and its execution, including recognition, designing, construction, development, maintenance, evaluation, and management of Tehran green space, have undergone fundamental and continuous changes in a framework of dynamic trend over the past 25 years. Some of the most significant challenges posed and strategies adopted to deal with them are as follow:

1. Due to rapid population growth, some parts of Tehran have limited area available. This hinders equitable distribution of green spaces and welfare facilities. To tackle the problem, Tehran Parks and Green Space Organization purchases land and changes the land use to establish public green spaces.
2. Severe air pollution, in addition to arid and semi-arid climate in Tehran, have imposed limitations on plant selection.    
3. Citizen interference (vandalism) inflicts damages to green spaces; therefore Tehran Parks and Green Space Organization (TPGSO) adopted the approach of planning with people instead of planning for people, through bottom-up collaborative planning. Furthermore, TPGSO makes attempt to built culture and broaden citizens knowledge concerning the importance of plants and green spaces through preparing and broadcasting radio/TV programs, installing informative billboards and banners across the city, and compiling educational pamphlet for public and students.
4. Limited financial resources hinder undertaking more research projects. TPGSO has already managed/finished 100 studies and executive research projects. If the organization is provided with enough credit it would expand its study and research projects and would involved more joint activities with universities, research centers and other respected centers. 

Lessons learned over 25 years of making attempts to develop Tehran green space shows that success can be achieved if measures are taken to meet public needs, satisfy citizen values, respect gender equity and serve women, young adults and children needs.

Some lessons learned while developing Tehran green space are:

• Sharpening the sense of citizenship

In metropolises such as Tehran, various areas including squares, sidewalks and public areas with different specific usages exist, but green spaces have the most usage regarding cultural aspect.

• Strengthening social equity

Three decades ago, one of the criteria used to show different classes of neighborhoods in Tehran was the total land area of green spaces and parks in the 22 districts of Tehran municipality. Accordingly, Tehran was divided into two parts: northern part (affluent) and southern part (deprived). Today, as a result of an attempt to achieve equitable distribution of green spaces across Tehran city, the above belief has changed and some areas in southern part of Tehran have even more green space per capita compared to the northern parts.

• Equipping park areas with sport facilities

Today, one of the main functions of parks and green spaces in Tehran city is sport. Installing sport tools and inviting volunteers to coach are appropriate motivation in order to attract citizens into parks and increase the number of green space interested citizens.

- Tehran Parks and Green Space Organization Constitution

- Geographical information station for tehran green spaces and gardens

- Comprehensive project of Tehran Green Belt

- Comprehensive project of irrigating Tehran green space by crude water

- Project on “Study the possible ways to achieve economical self-sufficiency of the forest and urban parks of the city of Tehran”

- Observe public perception (9 - 15 years olds) concerning green space and its impacts on psychological sanitary of the society