An urban garden is a place in a built-up metropolitan area where gardeners can grow a range of trees, shrubs, climbers, perennials, fruit and vegetables. There are a huge number of benefits related to urban gardening; improving air quality, providing green spaces for communities, promoting healthy eating as well as helping people to reduce their carbon footprint and lead a more sustainable lifestyle.
Different Types of Urban Gardens
There are many types of urban gardens from rooftop gardens, balcony and terraces to community gardens and allotments. Each of these areas have different requirements when it comes to planting so it’s important to use the right soil for the right growing environment.
1. Community Gardens
Community gardens will often be for mixed use, some recreational activities, and ornamental spaces for individual and family enjoyment, but also used for producing communal fruit and vegetable gardens. Therefore, it’s important that the soils are considered safe for the activities being undertaken, so it’s vital that soils used conform with the parameters of BS3882:2015.
- Soils for lawn areas need to have no added organic content to avoid any differential settlement prior to seeding or laying turf, for which our Boughton BLS 2 or British Sugar TOPSOIL’s Landscape20 are ideal soils.
- For areas planted with trees and shrubs, the addition of soil ameliorants like Green Waste Compost or Digestate help boost the soil organic content which is beneficial to its well-being and the biodiversity within the soil: Boughton’s BLS20 and BLS Plus as well as British Sugar TOPSOIL’s Hort Loam are ideal soils for these applications.
- Areas that may be used to produce food benefit from organic rich soils and also ones that are BS3882:2015 compliant, it’s important that these soils have a thorough chemical analysis to ensure crops are safe to grow in the soil; Boughton’s BLS 40 is a perfect partner being Green Waste Compost rich, ideal for growing fruit and vegetables.
2. Allotments
Allotments require an organic rich soil with regular soil ameliorants added to keep them topped up like additional green waste compost or well-rotted manure. A good way to start is using our Boughton’s BLS40 developed specifically for fruit and vegetables, which would be perfect for any new allotment development. Again, it’s important to ensure any soils for food production are BS3882:2015 tested to ensure it’s safe and contains no heavy metals that may cause harm.
3. Balcony and containerised areas
Container planting generally requires compost rich soils to benefit hungry and fast-growing annuals, perennials and some small shrubs and trees, Boughton’s BLS 40 is a great soil for this as it is up to 40% compost mix, depending on the depth of the container a subsoil may be required and some drainage. If weight is a concern, then, Boughton’s IN1 Intensive Substrate, one of our Green Roof products would be a perfect option, lighter than a standard soil, but still sufficient organic content to support a wide variety of planting. 
4. Raised beds
Like container gardening for balconies, Boughton’s BLS40 is a great option for raised beds both for general planting and raised beds for vegetables and fruit production. Soil depth should be limited to no more than 350-400mm due to the high organic content, any greater depth and anaerobic conditions could develop which would be detrimental to the plants. If the depth is greater, then using a subsoil in combination with the topsoil layer would overcome this issue.
5. Rooftop gardening
There are specialist products for roof gardens depending on the type of planting or effect required, whilst referred to as ‘Lightweight Soils’ they contain no soil and are a manufactured product. In all instances advice should be sought from a qualified structural engineer to ensure the roof structure can cope with the additional loading from the substrates used.
Extensive – Brown Roofs
These are roofs which are left for planting to naturally form from wind borne seed and also seeds brought in by birds and other wildlife – generally these are made from an ‘Extensive Substrate’ this is a combination of crushed new brick and Green Waste Compost, our product is known as Boughton’s EX1, it’s important that the crushed brick is a new brick opposed to a reclaimed brick, reclaimed brick could contain contaminants e.g. lead based paints. Extensive substrates can be used with a minimum depth of 80mm up to a max of 200mm.
Extensive – Sedum Roofs
These are the same as the Extensive Brown Roofs use predominately Sedum plant species. Sedum are a range of plants that tolerate dry conditions and can grow is shallow soil, they form a carpet of planting. Also, extensive roofs are generally not irrigated.
Biodiverse Roof
These roofs use a version of the Intensive substrate, but with a different ratio of materials, created to be a lower nutrient content providing the opportunity to grow a range of wildflower species. Roofs using this substrate can also be left unplanted to create a Biodiverse Brown Roof. Biodiverse substrates should ideally be at least 120mm depth to accommodate deep rooting plant material.
Intensive Roof
Intensive roofs use a substrate mix which is much richer and is designed for an intensive planting mix, much the same that you would find at ground level, so often large trees, shrubs, perennials climbers and lawns. This can obviously be scaled to small and large applications depending on the scope of the project. Our product for this application is Boughton’s IN1 Intensive Substrate.
