Vertical Gardening – The Real Pros & Cons

Flexible types of vertical gardens

If you’re short on space and missing out on some green-fingered action, then you should really give vertical gardening some serious thought.

As an urban gardening concept, vertical gardening / farming is loaded with benefits – improving air quality, mental health, food miles and even energy costs / usage in certain circumstances. Of course there are a few ‘downsides’ to consider, but that’s totally normal.

Table of Contents

Man spraying his vertical garden
Research into gardening really highlights the mental benefits, particularly in urban areas

Pros

Saves Space

  • Growing upwards in urban areas allows us to garden even without a balcony

Gardening or growing food in limited spaces has been an urban problem for a long-time. But gardening ‘up’ is growing in popularity and it’s easy to see why. Creating a green wall or roof is a phenomenal way to use otherwise unusable spaces to improve air quality, access to green areas and even the urban heat island effect.

But vertical projects don’t have to be that ambitious. You can use some pallets, freestanding vertical gardens or pocket planters to grow vertically as a starting point.

Mobility

  • If you use a vertical planter or pocket wall, you can simply move your 'garden' from one place to another

Depending on how you set up a vertical garden, it can be much more mobile than traditional gardening.

Utilising pocket planters or freestanding vertical planters means you can move your ‘garden’ to different areas when it’s been setup. For example, if you created a garden of summer-flowering pants and herbs that struggle in the winter, you can move them inside in harsher months to prevent them dying. And to provide a little indoor greenery.

This level of indoor and outdoor flexibility is a key feature of vertical gardening.

Flexibility of Design

  • Vertical walls can be your own urban green space - they have tremendous flexibility
Different styles of vertical gardens

Cities don’t lend themselves well to gardening as a general rule. The lack of ground space has long put off urban gardeners until recent times where there’s been a proliferation of living walls, green roofs, facades and vertical planters.

An ability to ‘own’ your own vertical space in urban areas is incredibly alluring. If you own a small balcony for example, you can grow climbing plants on a wall mounted trellis or pallet for minimal cost. Even more simple is a pre-built vertical planter that you can move in and outdoors based on the seasons. So you can plant more delicate flora and move them inside in harsher conditions such is the flexibility of vertical gardening.

Green walls and roofs are generally less flexibility and larger scale projects. But DIY green roofing is commonplace in London – and in other areas – and little gardens on top of balconies, shed roofs and even bin stores are designed at the owner’s volition.

Mental Wellbeing

  • Multiple studies and mental health awareness bodies back green space for alleviating depression-like symptoms

There are many arguments that suggest as a result of our evolutionary past, humans are predisposed to respond positively to cues (e.g., vegetation) that signal better chance of survival for our ancestors.

Green spaces have recently been give the thumbs up by mental health awareness bodies as a way to alleviate anxiety and depression. Particularly in urban areas. Multiple studies have highlighted how beneficial access to ‘the outdoors’ can be. Even just observing nature has substantial positive effects. And – surprisingly it doesn’t even have to be ‘real’ flora or vegetation. One.Japanese study simply found that it more beneficial psychologically to view a green hedge rather than a concrete fence.

Findings of a study on vertical walls and their restorative affect in New Cairo showed that the group exposed to vertical gardens was with higher restorative effect and lower stress levels. This proved that vertical gardens could enhance the quality of life through its restorative effect.

A unique VR-based study found that even the presence of vegetation in urban areas had a ‘stress buffering’ effect. Groups of participants were exposed to a stressor then saw vegetation in an urban area vs a group who just saw walls coloured green. Those exposed to vegetation were substantially calmer.

Pollution & Air Quality

  • Green walls are particularly effective at reducing N02 and particulate matter (PM10) =- prevalent in cities
A polluted city, shrouded in smog
Smog filled cities are rich in N-2 and particulate matter. Both of which can be mitigated by vertical gardens

Increasing plant coverage has long been considered as a versatile way to improve air quality in urban areas. But we’re always limited by space.

So an ability to grow vertically can have a huge impact on urban air quality. What you do need to be aware of is how important the choice of plant(s) is. Low maintenance succulents for example don’t have the capacity to significantly impact air quality and pollutants in cities. While plants are crucial for combating climate change, using plants to mitigate air pollution through the process of phytoremediation – changing carbon into oxygen – is more complex.

In Quito – a city with only 4% green space that regularly exceeds the WHO’s air quality guidelines safety levels – 14,000m² of green walls exist that help mitigate pollution levels. These vertical gardens caused a significant decrease in:

  • O3 (up to 99%)
  • NO2 (up to 80%)
  • SO2 (up to 83%)
  • PM2.5 (up to 79%)
  • M10 (up to 85%)

However much is dependent on the choice of plant species. In fact, a poor choice of plant species can even increase O3.

Lancaster University created a model showing that green walls are particularly effective in the process of reducing such pollution as NO2 and particulate matter PM10, in streets where both sides are lined continuously with buildings and where the air circulation is limited.

In such cases the pollution may be deposited on the green walls for a longer time. According to research, it is possible to reduce air pollution to as much as 40% for nitrogen dioxide and 60% for PM10 dust.

Noise Pollution

  • Up to 44% of EU residents are exposed to noise levels that are detrimental to health - even a little vegetation and substrate has an impact on building noise insulation

Whilst vertical planters won’t have any significant impact on noise pollution, wall mounted trellises and – the holy grail – legitimate living walls can substantially mitigate noise pollution in urban areas.

Up to 44% of EU residents are exposed to noise levels that are detrimental to health. And the presence of green facades is proven to decrease the amount of noise that can seep through walls. The key feature(s) in sound absorption is the substrate and the density of plants.

And the walls don’t need to be completely covered to achieve substantial noise pollution reduction. And the key factor in noise absorption is weight. Which, given walls do have a weight limit, is promising for urban areas negatively impacted by noise.

Slash Transport and Machinery Cost & Food Miles

  • Grpwing plants, herbs or food in urban areas substantially decreases transport and machinery costs, reducing the environmental impact

Whilst industrialisation has been a huge positive in terms of food cost and availability, to farm at scale efficiently you need space. Industrial agriculture, enabled by mechanisation, has led to plummeting consumer costs, allowing more food to be available to more people for less.

But big farms need big machines, with long straight lines for them to run down, which is not conducive to farming near people. So farming in cities reduces not only food miles, cost (of course it’s cheaper to grow your own after a certain scale) but the impact of machinery on the planet.

Vertical farming has the potential to significantly increase food production while reducing the environmental footprint of the agricultural sector by reducing land, water, chemical, and fertilizer use and increasing overall efficiency.

No Fertilisers or Pesticides (Even Soil)

  • Growing everything completely organically has never been so easy - supremely sustainable gardening / farming
Pesticide spraying with a huge tractor
Traditional farming can be very pesticide heavy

What you have access to, in growing your own food, is complete control over what you eat and the conditions it is grown in. If you are looking for completely organic, pesticide-free vegetables grown year round it’s completely achievable. Even in a city.

If you are willing to spend a little more on the perfect setup, indoor, vertical hydroponics systems are low weight, almost no maintenance farms where you can grow

At a large(r) scale vertical farming technology reduces carbon, water, pollution, and sustainability costs of conventional agriculture. Its potential yields and business model has also attracted the capital and expertise of big tech.

Cons

Expense

  • Vertical gardens can be setup very cheaply (even under £100), but the expense can really mount

Vertical gardens can be as expensive or as cost effective as you like. Some DIY vertical gardening systems can be setup for under £100. Even using leftover pallets or building your own trellises.

But some hydroponic systems cost hundreds if not thousands of pounds. If you’re looking to setup a vertical farm that produces substantial yield, the initial setup costs will be reasonably high. If you’re looking for a budget-friendly option, that’s very achievable too.

And if you let your plants die during harsher months, replacing them isn’t free.

Maintenance

  • You can setup vertical gardens that require (almost) zero maintenance. But regular irrigation, feeding and plant-care can be essential, potentially

Choosing the right plants is key if you’re looking for a low maintenance vertical garden. Green roofs setup with succulents and hardy evergreens / perennials are typically very low maintenance. But complete rooftop gardens with a variety of flora designed to sustain and even improve biodiversity may need a gardener.

And some vertical farming systems – particularly if you’re looking to grow substantial yield – will require irrigation and nutrients at a minimum. And pretty annual flowering plants may need to be brought inside during harsher months.

Structural Limitations

  • Some green walls and larger vertical structures can place significant stress on walls

Of course there are limitations surrounding how much additional stress the structure you choose can handle. If you plant herbs in a standalone vertical planter, this isn;t an issue. If you’re looking for a complete, thick green wall that will have an impact on noise and air pollution – even energy bills – you’ll need a professional to ensure its structural integrity.

Limited Range of Crops

  • Growing upwards in urban areas allows us to garden even without a balcony

It stands to reason that you can;t grow everything vertically. Crops that grow best underground for example probably aren’t a good idea for a personal project due to the amount of soil required. Although if you have the space and structural solidity it is definitely achievable.

And even heavier crops like melons and squash can be grown vertically. You’ll need to cradle them with a hammock like structure if they’re grown off the ground. But it absolutely can be done. Just be aware that you’re going to be limited in what you can and can’t grow!