花园在前所未有的时代中的作用

著：（德/加）丹尼尔·罗尔 （美）肖恩·贝利 译：魏菲宇

0 引言

在奥利弗·萨克斯（Oliver Sacks）的一篇题为《为什么我们需要花园》（“Why we need gardens”）的文章中，这位神经学家反思，“在40年的医疗实践中，我发现只有2种非药物‘疗法’对慢性神经系统疾病患者至关重要：音乐和花园”[1]。

花园是已知最古老的、由人类创造的建筑空间，在历史上有着多种用途。自从人们开始使用花园以来，花园就为人们提供了住所、娱乐和食物。1085—1145年，中国开设了第一批公立医院，从那时起治疗性的花园和庭院就是医院必不可少的组成部分[2]。今天，我们要特别指出花园具有疗愈和修复的功能。COVID-19所带来的社会影响，揭示了将花园和绿地重新纳入人们日常生活的必要性。

花园空间由人造的墙、栅栏或堤坝来界定。在人类农业文明早期，这些花园围栏保护着作物不被动物食用。花园不仅具有种植、生产、储藏的功能，还是人类进行“休闲”的场所。这种早期的“休闲”空间可以被定义为保护空间，以抵御野生动物、敌人以及环境因素对人类的侵扰。从一开始，花园就是人类远离尘世危险的避难所。

即使在今天依然如此。虽然当代花园在设计上已经很成熟，但功能仍然是一样的。在全球爆发新冠肺炎疫情这一前所未有的时期，花园在帮助缓解这一世界危机方面发挥了重要作用。花园是人们参观、娱乐和进行创造的地方，是触觉、嗅觉、听觉、味觉和视觉等多种感官体验的天堂。爱德华·威尔逊（Edward O.Wilson）在《亲生命性》（Biophilia）[3]中说道，人类有一种与生俱来的冲动，要与其他生命形式建立联系并进行互动。如今，花园继续发挥着保护作用，因为使用花园不仅可以对人的身心健康产生积极影响[4]，而且研究还表明它们是具有高度疗愈性的空间[5]32,58。通过花园生产食物，可以减少人们对食物供应链的依赖，进而减少CO2的排放。如果考虑生态因素，花园可以构成城市生物群落生境，并成为候鸟和其他动物的聚集地。相邻的花园或在每个建筑结构中所包含的花园，可以极大地改善城市基础设施，为雨水管理提供透水空间，通过园中的植被减少城市热岛效应，并为动物提供栖息地。花园可以在不透水的城市环境和透水的城市绿色空间之间实现部分平衡，是城市结构的重要组成部分。

本研究试图回答以下紧迫的问题：1）在当今史无前例的疫情中，花园起到了什么作用？2）这次疫情将如何改变人们对城市中花园和公园的观念？3）规划师和设计师如何在城市中创建更多的花园和绿地，以减轻COVID-19危机及其对未来产生的影响？

1 当前花园的作用

自2020年4月以来[6]，全球有1/3的人口处于封闭状态。从最近谷歌地图有关全球城市开放空间和公园使用情况统计数据中可以看出，人们比以往更渴望在户外呼吸新鲜空气和享受阳光[7]。由于人们无法像往常一样和家人朋友们自由交往、聚会，花园因此可以缓解人们的分离焦虑。

花园可以成为人们躲避病毒的空间，让人们更安全地进行交流。作为我们居住建筑的一部分或其延伸，花园不仅提供休息、活动空间，同时也是人们观察和体验微型生物群落的场所。与有空调和供暖的室内空间相比，花园是不断变化的微观世界的一部分——土壤中充满了微生物，植物生长和死亡，气候不断变化。对于使用者来说，花园提供多感官的体验。花园是一个整体系统，可以连续地以不同的方式激发我们的感官：味觉、嗅觉、视觉、触觉和听觉。例如，如果下雨，微冷却的空气会产生不同的气味，这与花园暴露于阳光下数天后闻起来的干燥气味不同。在花园里剪草之后，可以闻到草屑的清新气息，看到成熟的果实或闻到它们的香味，也可以闻到玫瑰的芬芳，触摸到它柔软的花瓣。

有大量证据表明，与自然接触有益于人们的身心健康[5]32,56-58,[8-12]。尽管关于这些益处的讨论在很大程度上都是围绕着视觉方面展开的，但仍有许多方法可以通过非视觉的方式来实现[13-14]。例如，人们发现城市道路的噪声会导致人们血压升高，进而对个人健康产生负面影响[15]。而增加城市绿地可缓解噪声污染[11]121-122。同样已被证明的是，当人们身处自然气味（例如开花植物的气味）中，有利于平静情绪和心情[12]443-445。尽管目前关于人们触摸植物是否有益健康的研究较少[13]10，但已证明人际交往对于人与人之间建立纽带至关重要[16]。世界卫生组织密切关注COVID-19对人们心理健康所产生的负面影响[17]，而城市绿地及其提供的多种感官体验，可以成为减轻这些负面影响的重要工具。

在过去的30年里，园林设计通常关注于植物色彩和质感的视觉效果，以及不同类型景观材料的使用。人们为了避免维护所带来的经济负担，通常会控制植物的选用。然而繁茂的植被增加了场地的生态价值，也增强了花园的修复和疗愈功能。但目前在园林设计中，有意识地强调其他感官体验的花园却较为罕见。笔者建议不仅要关注花园的视觉效果，还要针对气味、声音、触感和味道进行设计。设计师在花园中设计出多重的感官体验，可以增强其设计场地的疗愈效能和整体体验。由于城市绿地和花园具有多种感官优势，因此设计师应该意识到要为所有感官而设计，而非仅为视觉而设计。如果花园设计师引导花园的使用者和游客有意识地体验多种感觉，例如闻花香、品尝水果和触摸植物，将会有效提升花园的疗愈功能并缓解人们的身心压力。

众所周知，花园和公园在缓解人类健康危机方面具有重要作用。例如弗雷德里克·奥姆斯特德（Frederick Law Olmsted）于1870年在波士顿设计了“翡翠项链”，创建了一系列连续的公园，将城市结构与居民和户外活动空间连接起来，并治理了霍乱病毒污染的城市雨水和污水[18]。公园还充当了城市及周边地区的“绿肺”，为工人提供清洁的空气。借助目前关于绿色开放空间对城市社区的疗愈作用的研究成果[9,14]，当前的这一危机更加激励了设计师应该重新思考他们关于建筑和花园的观念和设计，以包容所有的使用者感官体验并作为建筑空间的一部分。花园不是室外的房间，它们是建筑物的一部分。它们是建筑空间，也是社交空间。

在此次疫情之后建造的花园，设计的重点应该放在使用者所有的感官体验上，以最大限度地提高它们的疗愈作用。为此，建议设计者在设计时将视觉与味觉、触觉、听觉和嗅觉同等对待。首先要考虑每个花园与所在建筑功能相关的活动，并确定其优先顺序。这些活动可能有助于在花园设计中开发更具多重感官体验的活动。所以在文章最后，笔者提出了一个设计优先级列表来支持设计初始阶段的花园构想。

许多花园设计思想并不是新理论，但是可能已经被人们逐渐遗忘，或者设计师没有有意识地将花园设计成具备多重感官体验的空间。例如，第一次和第二次世界大战出现的胜利花园（the victory gardens）是人们为了生存而进行粮食生产所设计的花园，而没有关注花园的嗅觉或味觉[19]。同样，德国的分配花园（the allotment gardens）也是为娱乐、园艺和食品生产目的而设计的[20]，也不是出于其可能产生的气味和味道的疗愈效果而设计。随着今天对花园的疗愈作用和感官体验的研究，设计师们需要重新思考城市花园设计理念。

2 城市中花园的可达性

在城市之间和城市内部，人们在使用绿地方面存在的差异性已得到充分证明[21-22]。这些差异往往反映了社会的不平等性[23]。COVID-19的爆发使这一不平等性变得更加严峻。由于数百万人被隔离在家中，无法走出家门，公园和花园已成为重要的社会基础设施。

规划人员正通过这场危机，加速汽车型城市的转变[24]，并使残疾人更容易进入城市[25]。城市规划者、城市设计师、风景园林师和建筑师也应该将这场危机视为契机，为花园提供更多的空间，而不是为建筑设计提供更多空间。笔者建议设计师们应该在建筑设计过程中突出花园的功能及开放空间的使用，强调花园是建筑设计的一部分。这场危机进一步说明，设计师需要在其方案中强调花园的地位，并根据不同的尺度规模采取不同的设计策略（图1）。

应如何实现上述目标呢？进行多尺度规划的风景园林师可以重新思考未来和现有的花园，这原本就是其重要的工作范畴之一。这些绿色的花园好比城市的“绿肺”，需要解决当今城市在雨水管理、热岛效应以及小气候营造等方面的问题，并突出对气候变化的适应性。例如：提供繁茂的植被来减少城市热岛效应；以低影响开发技术来管理雨水；提供蔬菜种植区来增加城市的食物产量；提供植物和空间来吸引动物，营造迁徙鸟类的栖息地，从而提高花园的生态价值。在市中心的花园中，透水空间很少，所以应优先考虑增加土壤与地下水位相连的透水区域，因为这可以逐渐恢复城市中日益降低的地下水位，并维持植物生长，从而改善生态环境，为使用者提供更丰富的感官体验。当建筑中没有足够的与地下水位相连的透水区时，可以将密集的绿色屋顶作为丰富的植物种植区[26]。但通常情况下，花园作为室内空间的延伸，将室内的设计语汇转移到室外，设计师往往忽视了平衡硬质景观和软质景观。例如，一处大面积的不透水露台空间，能留给植物的生长空间很少，更不能用来管理建筑物的雨水径流。

这次疫情为我们提供了一个重新思考城市中花园的机会。难道不是所有的建筑都应该有一个包含多种感官体验的花园吗？难道花园不应该是每个建筑的一部分吗？公寓大楼的居民进入花园就如同外科医生和护士需要在花园里休息和充电一样[27]。COVID-19使生活在养老院的老人们因家人无法探望而倍感孤单，花园可以帮助缓解这一问题。当养老院的老年人更多地使用花园等设施时，他们可以变得更健康，同时“孤独感”也有所改善[28]。

花园是多功能空间，可满足不同的使用需求。在大多数建筑项目中，花园被视为一种附加物、额外的奢侈品。但如果我们回顾历史悠久的罗马、波斯和中国建筑，则会发现许多建筑内部都有中庭或是贯穿房子的花园。花园是建筑物的核心，它将新鲜空气导入各个房间，改善了夏季小气候。花园保护开放空间免受强风的侵袭，提供自然采光，并在房间之间提供独立通道。中庭和花园就像一个开放空间的过渡区，在不同的房间之间形成一处闸门。花园是这些建筑的核心，并定义了围绕其布局的房间功能。

这些历史悠久的花园即便是人为营造的空间，也可以给使用者带来不同的体验。它们不仅可以调节小气候，而且围合的花园空间可以产生浓郁的花香和果香，丰富人们在花园中的整体感受。当今的很多城市设计和建筑设计都包含花园，但它们往往被放置在建筑物周围的剩余空间中或者作为建筑空间的附属部分。很少有人认为花园是建筑、城市街区或城市空间规划设计的引领要素。

然而也有一些值得关注的例外，但这类实例应该有更多。位于澳大利亚南布里斯班的奇伦托夫人儿童医院，为病人和他们的家人提供了充足的绿地和花园[29]。该设计已被证明对医院的使用者具有一定积极的作用[30]。在布宜诺斯艾利斯大学，“Zero + Infinite”建筑项目是一处教育设施，其设计模糊了建筑和环境之间的界限[31]。它由一个8 800 m2的绿色屋顶组成，并使用透明结构将自然景观和内部庭院联系起来，实现了内外空间景物的相互渗透。

在一些绿色建筑的外立面上，为种植树木或水培植物提供了生长介质。近来最杰出的项目之一是Stefan Boeri在米兰的Bosco Verticale。在该项目中，设计师将树木种植在外墙内的集成容器中[32]。同样，帕特里克·布兰克（Patrick Blanc）在原有或新建的建筑立面上用水培法种植植物，形成垂直绿墙，成为绿色建筑的一部分[33]。这些项目凸显了植被在清洁城市空气、改善微气候或作为一种愉悦的视觉审美体验的重要性。它们还提升了绿色开放空间的价值，使公众意识到城市中植物和生境的生态重要性。这些解决方案对城市开放空间中的种植非常重要，但由于它们是人为创建的解决方案，需要进行人工灌溉等持续的能源投入。然而对其体验的观察研究表明，它们可以对使用者和患者的健康产生积极影响[5,34-35]。在现有的密集城市中，由于没有透水空间可供使用，这种种植方式是对密集城市空间的妥协。

此外，绿色屋顶可以为公众提供可到达的使用空间，并可以种植更多种类的植物，因此可以称之为花园。但是与绿色外墙技术一样，它们是人为的解决方案，需要进行大量维护和能源供给才能使其延续。研究表明，绿色屋顶的确有很多优点，例如：减少雨水径流；冷却或维持建筑物的热量；营造微型生物群落和增加生物多样性；营造微气候以及美学与疗愈价值[36-37]。由于大面积的绿色屋顶与自然地表及其自然排水能力没有直接联系，设计师需要考虑屋顶有限的承载能力，来设计软质及硬质景观。人们对绿色屋顶的雨水管理[38]和生态效益进行了深入的研究[39]。绿色屋顶的另一个优势是它的隔音效果较好[40-41]，从而可以降低与人体血压升高相关的城市噪声[15]。虽然绿色屋顶在某些方面具有局限性，但其对城市和居民所带来的积极影响应受到重视。

3 新型的花园规划设计工具

本研究中，笔者提出了一个广泛适用的规划列表，以支持城市规划师和设计师在规划新城或修订现有规划策略时，将花园作为其建筑开发策略和规划设计的一部分。城市花园不应是完成城市规划之后的想法，而应在总体规划和建筑设计过程中作为规划的一部分。实际上花园不仅是建筑物的一部分，它们应该是建筑设计的核心。这不仅适用于单个建筑物，而且同样可用于城市街区或城市的设计。设计方案应将花园与建筑的设计结合起来，以避免建筑与花园的割裂。花园是……建筑！

在人口密集的城市中，开放空间稀缺，为了帮助设计师设计城市花园中的主要活动空间，首先要在总体设计层面确定花园活动内容的优先序列。由市政机构在初始设计阶段给出指导，然后在规划许可范围内纳入花园规划计划。笔者提出了一个花园活动优先级列表（表1～2），以便在设计初始阶段确定花园功能。这个列表为城市中的一些主要建筑类型提供了详细的花园活动建议。为了确定花园活动对某个项目的重要性，提出了以下4个等级的排名：极高——设计中具备针对性的花园活动空间；高——设计中具备一些具体的园林活动空间；中——设计中具备最低限度的花园活动空间；低——设计中不需要考虑花园活动空间。该列表可以帮助规划人员为拟建的新建筑中的花园提供详细的规划要求。笔者建议在每个城市组建一个由风景园林师、规划师和建筑师所形成的团队共同完成以上4个等级的排名，基于每个城市自身的文化背景，提出花园设计的重点和政策。

该工具是设计师确定城市及建筑中花园空间所占比例及密度的一种方法。它能够确保在城市中提供更多的花园空间，并将花园视为城市建筑的重要组成部分。在人口稠密的城市中，需要针对每种建筑的类型和特定需求进行宝贵的户外空间设计，以减轻诸如COVID-19等危机带来的影响。

4 具有缓解效应的花园

城市中的所有建筑都应该将花园空间作为其设计的一部分。本文作者提出的工具为城市中不同等级的花园提供了可参考的花园活动。包括屋顶花园（集中的绿色屋顶）或相似的结构——技术层面上其属于绿色屋顶。

当在规划许可文件之前制定城市设计概念方案时，花园活动优先列表确定了哪些活动应该包含在这些花园中。开发者必须在获得规划许可之前应用这份清单，以避免花园成为规划之后的附属产物。花园应作为建筑方案的一部分进行设计，是建筑空间及其功能的一部分。该列表将支持设计师将重点放在特定的优先级设计上。

花园活动清单有助于开发建筑空间，并优先考虑与建筑类型相关的花园活动。例如，之所以“治疗性”的花园在医院建筑中的等级非常高，是因为设计师可以提供诸如玫瑰之类的芳香植物。通过这类植物的使用以激发使用者的记忆力，并且具备治疗性的放松镇定效果[42]。治疗性的花园还可以提供舒适的户外座椅，使病人可以接触植物，缓解就医带来的压力。花园可以为使用者提供色彩柔和的草本植物，或通过让使用者触摸柔软质地的观叶植物，起到稳定情绪的作用。

该清单的目的是为决策者和规划人员提供一种扩展工具，以便在决定建筑空间规划时对花园活动进行优先排序以将其纳入前期规划中。这将提高规划师和建筑师对花园规划设计的意识，在规划方案的一开始就将花园作为建筑空间的一部分。

5 结论

笔者在文中总结了城市花园对人类的健康裨益。由于在新冠肺炎疫情期间，需要人们大幅度地减少社交活动，因此更加突出了城市花园的重要性。在目前的城市规划和建筑设计中，花园通常被视为附加设施，而不是建筑空间的必要组成部分，笔者建议应从一开始就将花园空间纳入建筑设计中。从规划的角度来看，城市应将花园空间纳入其分区规则和城市设计导则中，以便新建项目能够充分利用场地现有的条件，提供充足的花园空间。市政当局可以使用花园活动优先级列表作为优先考虑不同建筑需求的参照。不同城市需要根据自身特点开发不同版本的花园活动优先级列表，以便为相关从业人员提供规划设计指导，将花园更好地纳入开发项目中。此外笔者倡导围绕多重感官体验为重点的花园设计，并进一步研究此类花园对使用者健康的影响。

致谢：

感谢 Jessica Udal、Jane Green和 Rebecca Anderson对本文写作上的帮助，以及内达·鲁尼亚提供的图片。

图表来源：

文中图表均由丹尼尔·罗尔创建，由内达·鲁尼亚绘制。

Gardens are… Buildings: A Garden's Role in Unprecedented Times

Authors: (DEU / CAN) Daniel Roehr, (USA) Sean Bailey Translator: WEI Feiyu

0 Introduction

In an essay by Oliver Sacks entitled “Why We Need Gardens,” the neurologist reflects, “In forty years of medical practice, I have found only two types of non-pharmaceutical ‘therapy' to be vitally important for patients with chronic neurological diseases: music and gardens”[1].

Gardens are some of the oldest humancreated architectural spaces known and have served a number of purposes throughout history.For as long as they have been used by people,gardens have provided shelter, pleasure, and food. Therapeutic gardens and courtyards were essential to the first public hospitals that opened in China between 1085 and 1145[2]. Today, there is an opportunity to emphasize the healing and restorative qualities gardens bring to our lives. The societal impact of COVID-19 has unveiled the need to bring gardens and greenspace back into the forefront of everyday experience.

Garden spaces were defined by walls, fences and dykes created by man. Those garden enclosures protected the crops from being eaten by animals in the early years of human agriculture. Gardens were places of food cultivation, production, storage,cooking and leisure. Leisure in the early ages could be defined as protective spaces against wild animals,hostile humans, and the environmental elements.Since their early beginnings, gardens were retreats and offered escape from the dangers of the world.

This has not changed even today. Though gardens have evolved in their design sophistication,their contemporary function remains the same.In these unprecedented times of the COVID-19 pandemic, a period which could be compared with the Spanish flu and following world depression a hundred years ago, gardens have regained importance in helping to mitigate this world crisis.They are a place to visit, recreate and create.Gardens are havens for multi-sensorial experiences of touch, smell, sound, taste and sight. Edward O.Wilson asserted inBiophilia(1984)[3]that humans have an innate urge to affiliate and interact with other forms of life. Today, gardens continue to play a protective role as using them can not only impact one's physical and mental health positively[4]but research on gardens also suggests that they are highly therapeutic spaces[5]. Gardens also provide personal and environmental benefit as tools for personal food production, effectively working to reduce dependence on complex international CO2emitting food chains. Gardens, if designed with ecology in mind, can be urban biotopes and act as hubs for migrating birds and other animal species. A set of adjacent gardens or the inclusion of gardens within the structure of every building could greatly work to enhance the urban infrastructure, providing pervious space for stormwater management,reduction of the heat island effect through vegetation and spaces for animals. Gardens can partially balance the impervious built urbanscapes with pervious green urban space. They are an important part of the urban fabric.

This article tries to answer the following urgent questions: 1) What role does a garden have today in this unprecedented pandemic? 2) How will this pandemic alter the opinion on access in cities to local gardens and parks? 3) And how can planners and designers help to provide more gardens and greenspace in cities to help to mitigate the effects during and after the COVID-19 crisis and in future crises?

1 The Role of the Garden in 2020

With a third of the world's population in lockdown since April 2020[6], the need to go outside just to breathe fresh air and capture some sunlight is apparent from recent Google Maps statistics on open space and park users in cities around the world[7]. Because people are not able to move and gather as freely with family and friends, gardens can play a major role in mitigating the stress of being inside and separated from our loved ones.

Gardens can be spaces of retreat and escape from the virus' physical impacts to meet more safely.As extensions and part of the buildings we live in, gardens are places that simultaneously provide space for rest, activity, as well as opportunities to observe and experience a designed micro biotope.In comparison to a controlled indoor space with air-conditioning and heating, gardens are part of a continuously changing microcosmos. The soil is active with microorganisms, plants grow and die and the climate changes constantly. Gardens are a multi-sensorial experience for the user. A garden is a multi-sensory experience and a holistic living system that simulates our senses: taste, smell, sight,touch and sound constantly in different ways. For example, if it rains, the humidity in the air creates a different smell and micro-cooling effect than if the garden has been exposed to sunshine for days and smells dry. Or, after the grass is cut in a garden one can smell the freshness of the grass cuttings, or see and smell the ripening of a fruit or touch and smell the soft petals of a rose.

There is abundant evidence that engaging with nature can benefit peoples' mental and physical health[5,8-12]. Though the conversation surrounding these benefits has largely leaned toward the visual aspects of nature, there are a number of ways that these benefits are achieved through non-visual senses[13-14]. For instance, urban noise, such as road traffic, has been found to have negative impacts on individuals' health by increasing blood pressure levels[15]. Increasing access to urban green areas can relieve the negative impacts of noise pollution[11].Similarly, exposure to natural odors, such as those derived from blooming plants, has been shown to increase calmness, alertness, and mood in study participants[12]. Although there is little research available on the health benefits of touching nonanimal beings such as grass or plants[13], it has been shown that interpersonal touch is crucial to creating bonds between people, strengthening relationships, and reducing stress[16]. As the World Health Organization has expressed serious concern regarding the negative mental health impacts of COVID-19[17], urban green space and the multisensorial benefits they provide can be an important tool to help mitigate these impacts.

Garden design in the last thirty years has often focused on sight and the visual colour and textural sensations of plantings, sophisticated and minimalistic use of new hard and soft landscape materials and often a sparse use of plants due to the fear of intensive maintenance. Lush vegetation,however, increases the ecological value of a site and with it the healing and therapeutic effects of gardens. A deep involvement to consciously include the other main senses intentionally has been rare.The authors suggest a major refocus not only on the visual effects of a garden but also designing for its smell, sound, touch and taste. Designers who devise a multi-sensorial experience in their gardens increase the therapeutic value and holistic experience of their designs. As the multi-sensorial benefits of urban green space and gardens is clear,designers should be conscious of all the senses rather than primarily designing for sight. If the users and visitors of gardens are invited by the garden designers to consciously experience multi-sensorial sensations such as smelling the flowers, tasting the fruit and touching the plants, the healing and stress relief of the gardens will be most effective.

The role of gardens and parks to mitigate health crises is not new. For example, Frederick Law Olmsted designed the Green Emerald Necklace in Boston in 1870 to create a set of linked parks to connect the urban fabric and its dwellers with the outdoors and to manage the stormwater and sewage from the Cholera infected city[18]. Parks also acted as green lungs close to the cities and provided workers with clean air. With the knowledge and research available today on the therapeutic impacts of green open space in urban communities[9,14],this crisis should motivative designers to rethink seeing their building and garden concepts and designs in order to be more inclusive to all senses and as part of one architectural space. Gardens are not outdoor rooms; they are part of the buildings.They are building spaces and they are social spaces.

In gardens built following the pandemic, the focus of design should be on all senses in order to maximize their healing and therapeutic qualities. To achieve this, it is recommended that sight be equally balanced with taste, touch, sound and smell when designing. Prioritizing which activities are needed in each garden relating to the building typology might support the development of more conscious multisensorial experiences and activities in the garden.At the end of the paper, a design priority list is proposed to support initial design ideas.

Many garden design ideas are not new but may have been forgotten or not consciously designed as multi-sensorial experiences. For example, in the victory gardens of the first and second World Wars the focus was on food production for survival and not necessarily on smell or taste sensation[19].Similarly, the allotment gardens of Germany were designed for recreation, gardening, horticulture and food production purposes[20]and not the therapeutic impacts of smell and taste that a vegetable garden or fruit orchard may have on the visitor. With the research available today on the restorative impacts of gardens and the experience of the senses, designers have an opportunity to rethink their design concepts for gardens in cities.

2 Urban Access to Gardens and Parks

The disparities in access to greenspace amongst and within urban areas has been well documented[21-22]. These disparities often mirror other social inequalities[23]. COVID-19 has made these disparities all the more critical. As millions are quarantined at home and unable to venture out beyond their own neighbourhood, parks and gardens have become even more important pieces of social infrastructure.

Just as planners are seeing this crisis as an opportunity to speed up the transition away from cars in cities[24]and to make cities more accessible to those with disabilities[25], city planners, urban designers, landscape architects and architects should see this crisis as an opportunity to provide more space for gardens in, instead of around buildings they are designing. The authors, as many designers before them, suggest that designers should support garden inclusion or access to open space in all their building designs. Gardens are part of building design. This crisis further exposes the need of designers to lobby for gardens in their schemes and act from the urban planning to the building design scale (Fig. 1).

How can this be achieved? Landscape architects who plan at multiple scales could partially return and rethink future and existing gardens — one of the original components of their profession. These green lung gardens must address the research knowledge we have today on stormwater management, heat island effect and the positive impact they have on microclimate and climate change issues. For example: providing lush vegetation to reduce the heat island effect, Low Impact Development to manage stormwater and increasing local food production by providing vegetable growing areas, and improving the ecological value of gardens by providing plants and spaces encouraging animal life and habitat for migrating birds to land. In inner city gardens pervious spaces are scarce. Increasing pervious areas with soil connecting to the ground water table should be a priority, as this will recharge the diminishing water tables in cities and support lush plant growth, thus better ecological habitats and thus a richer multi-sensorial experience. Where this is not possible, intensive green roofs can provide a wider plant palette[26]. Too often gardens are mainly designed as living room extensions, transferring the design language of the interior to the outdoors,forgetting to balance hard landscape with soft landscape. For example, a large impervious terrace space leaves little room for plants to thrive or manage part of the building's rainwater runoff.

The pandemic gives us an opportunity now to rethink gardens in cities and add to their already known and designed purpose as described above.Shouldn't all buildings have a garden that includes a multi-sensorial experience, and should the garden not be part of every building? The residents of apartment buildings need garden access as much as surgeons and nurses in a hospital need a garden space to rest and recharge for another operation or exposure to a deadly virus[27]. COVID-19 has worsened social isolation for senior citizens living in care homes as their families have been unable to visit. Gardens can help alleviate this. Seniors in residential care homes experienced improved perceived health and a sense of “being away” when their access to facility gardens was increased[28].

Gardens are multi-purpose spaces and adaptable to different functions. In most building projects the designed garden is seen as an add on,an additional luxury. If we look at historic Roman,Persian and Chinese architecture, many of the owners had an atrium or garden inside the house or a garden perforating the house. The garden was the centrepiece of the building. It introduced fresh air into the individual rooms, changed the microclimate in summer with cooling pools, protected the open space from strong winds, provided natural daylight and provided separate access between rooms.The atrium and garden acted like an open-space transition zone, a sluice gate between the different rooms. Gardens were the heart of those buildings and defined the arrangement of rooms assembled around them.

These historic gardens were man-made,controlled spaces to experience the different senses. They consciously engaged how one felt in the garden through the microclimate of cool or warmer air “touching” the skin, the concentrated scents due to the enclosed atrium space and the taste of fruit of orchards in the garden. Today's urban design and buildings include gardens, but too often they are placed in leftover spaces around buildings with little value or used or as an add on to the building space. One rarely sees the garden being a driver of the spatial concept of a building,city block or urban space.

There are, however, some notable exceptions but there should be many more. The Lady Cilento Children's Hospital in South Brisbane, Australia incorporates ample greenspace and gardens for patients and their families[29]. The design has been shown to have its proven effect on patients and visitors seeking a “time out” from their experiences in the hospital[30]. At the University of Buenos Aires, the Zero + Infinite project is an educational facility that blurs the line between the building and landscape[31]. It consists of an 8,800 square-meter green roof and uses its see-through structure to bring the natural landscape and courtyards from outside to inside and vice versa.

There are also green buildings where facades provide a growing medium to plant trees or hydroponic plants. One of the most prominent recent projects is the Bosco Verticale in Milan by Stefan Boeri where the trees are planted within the facade in integrated containers[32]. Similarly,Patrick Blanc's vertical green walls planted with hydroponics on existing or new building facades are also part of the green building movement[33]. These projects highlight the importance of vegetation in cities to clean the air, improve the microclimate or act as an aesthetically pleasing visual experience.They have also increased the value of green open space and made the public aware of the ecological importance of plants and habitats within cities.These solutions are important in the discourse of planted open space provision in cities but are not fully functioning accessible gardens, as they are man-made engineered solutions, which need continuous energy input such as artificial irrigation.However, research has shown that their view experience can have positive effects on peoples and patients' health[5,34-35]. They are a vegetated compromise in existing dense cities where no pervious spaces are available.

Living and green roofs on the other hand are different. They do provide public access and allow a wider plant palette and could be called gardens, however, as with green facades, they are man-made engineered solutions and need intensive maintenance and energy to keep them alive. Research has shown that they do have many additional benefits such as stormwater runoff reduction, cooling or preserving the heat of buildings, micro biotopes and an option of increased biodiversity, creation of a microclimate and aesthetic and therapeutic values[36-37]. Extensive green roofs and green roof gardens do not have the connection to natural soils and their natural drainage capacity as well as the benefits of designing freely for soft and hard landscapes without thinking about the limited load bearing capacity of a roof.Nonetheless, their stormwater management[38]and ecological benefits are thoroughly researched[39].Another benefit found with green roofs is their sound dampening qualities[40-41], and thus reducing the urban noise linked to increased blood pressure in individuals[15]. While green roofs are in some ways limited, their impact on cities and peoples' wellbeing should not be ignored.

3 The New Garden Planning Tool

In this article, the authors proposed a broad planning matrix which supports urban planners and designers when planning new cities or revising existing city planning strategies to integrate gardens as part of their building policies and design approach. Access to urban gardens should not be an afterthought, but rather should always be part of the planning process when buildings are proposed and designed. Gardens are in fact part of the building; they are the entrance and centrepiece from which the room program should be developed. This applies to individual buildings,city blocks or urban design proposals. The design proposals should integrate gardens with the design of buildings to avoid the separation between building and garden. Gardens are … buildings!

To help with the decision of what the main activities in those city gardens are, it is important to prioritize the garden's activity content, as open space is scarce in dense cities. In the concept phase of an urban design proposal, direction should be given by municipal institutions during the initial design stage before the planning permission meetings to include gardens. The authors developed a Garden Activity Priority Checklist to be used to support the design thinking process from the outset (Tab. 1-2). This list suggests detailed garden activities for the main building types in cities. To determine a garden activity's importance to a certain project, a four-stage ranking is proposed. Very High: Design should provide focused specific garden activity measures,High: Design should provide some specific garden activity measures, Medium: Design should provide minimum garden activity measures, Low: Design does not need to provide garden activity measures.This list will help planners in municipalities to provide detailed program requirements for gardens in proposed new buildings. The ranking should be carried out in each municipality by a group of landscape architects, planners and architects. Each municipality has their own design priorities, policies and culture of living.

This tool is an additional method for planners to decide the distribution and activities of garden spaces in cities and its buildings. It has the ability to make sure that more garden space is provided in cities and that gardens are seen as an important part of urban architecture as buildings. The limited valuable outdoor spaces in dense cities must be designed responsibly for the specific needs of each building typology to mitigate the impacts of a crisis such as COVID-19.

4 Gardens as a Mitigating Effect

All buildings in cities should provide a garden space as part of their building design. This tool provides garden activities specifically for gardens in cities at grade and includes roof gardens (intensive green roofs) or at grade above sub-structures —technically a green roof.

The Garden Activity Priority Checklist determines what activity should preferably be included in those gardens when developing urban design proposals to building design concepts prior to planning permission documents. Applying the list has to be done before planning permission,to avoid gardens being an afterthought. Gardens should be designed as part of the building proposal; gardens are part of the architectural space and how it functions. This list will support designers to focus on specific design priorities.

The garden activity list assists universally in developing the buildings spatial activity programming and prioritizes the garden activities importance in relation to the building typology. For example, the garden activity “therapy” is ranked very high by the authors in hospitals. Why? Here the designer can provide, for example, scented vegetation such as roses which stimulate past personal memories and may have a therapeutic relaxing and calming effect[42].Therapeutic gardens may also provide comfortable outdoor seating focused with a view into vegetation which can initiate relaxation from the hospital stress.For example, this may be done by providing views of modest soft coloured gentle moving herbaceous planting or easy access to soft textured grasses that stimulate a calming sensation of the skin when touched.

The intention behind the list is to provide policy makers and municipality planning staff with an augmentative tool to rank and prioritize garden activities for their inclusion when deciding the buildings' spatial program. This will increase awareness of planners and designers to include gardens as part of all building typologies at the outset of a building's proposal.

5 Conclusion

In this paper, the authors have laid out the health benefits of urban gardens. The COVID-19 pandemic presents the need for increasing access to gardens throughout cities as they can mitigate the impacts of social distancing on individuals.Buildings should integrate garden space into their design from the very beginning. Currently, gardens are seen as more of an add-on rather than a necessary part of any built space. From a planning perspective, cities should incorporate garden space into their zoning codes and urban design guidelines so that new developments provide adequate access to natural environments within them. As a means to implement this, municipalities can use the Garden Activity Priority Checklist as a starting point to prioritize their own needs. By developing their own version of the Garden Activity Priority Checklist,cities can more easily inform any zoning or design guidelines to better incorporate gardens into the typology of new developments. The authors suggest that more research be done to examine the impacts of multi-sensory focused design in gardens and the subsequent health benefits.

Acknowledgments:

The authors would like to thank Jessica Udal, Jane Green and Rebecca Anderson for their editing and Neda Roohnia for the drawings.

Sources of Figure and Tables:

The figure and tables are created by Daniel Roehr and rendered by Neda Roohnia.

(Editor / WANG Yaying)