Container Planting vs Soil Beds

Terrace gardens can be one of two types — set in planters/ containers, or with substrate applied directly to the terrace floor (soil beds).

Both methods have different advantages, but which method you choose will also depend on your building’s structural integrity. Considerations like weight or load bearing capacity and waterproofing are key, and it is recommended that unless your building is specifically built to support a full garden on the terrace, the much easier method will be to use light weight containers.

If your building is able to support direct planting, the main advantage of this method is that you will be able to utilize a larger portion of your terrace to plant your crops. Layouts of your crops will be similar to strategies for planting directly on the ground, keeping in mind that depth of soil on terraces is a limiting factor, so deep rooted crops cannot be grown.

Compare this to container planting, where area of cultivation will be more limited and defined by the number and size of the planters/containers you use. A significant advantage of container planting though is that a lot less roof preparation will be required and that it is mobile – easy to relocate and rearrange. Using containers will also limit any possibility of root damage to the building structure, and will be easier to manage.

It is best to check if your building has a structural stability certificate, which is mandatory for any construction, or get a structural engineer to determine strength and load bearing capacity. You may also want to consult a specialist who can help you set up a terrace garden by referring to our Service Directory.

Containers & Crop Selection

It is recommended to grow plants in grow bags or other light weight alternatives rather than cement or clay pots in order to reduce the load on the building. In addition to being lighter, containers like grow bags are also easy to handle and move around, if required.

Some plants are more suited to grow on terraces and balconies than others. For instance, leafy vegetables such as tomato, egg plant, okra, greens and herbs do well on rooftops and/ or balconies as opposed to fruit trees like Jackfruit, Moringa, Banana, Mango or Coconut that demand lots of soil and have deep and wide-spreading roots. Therefore larger fruit bearing trees or plants with deep growing tap roots are best avoided, though lots of our Thottakara Champions grow dwarf varieties of trees like Guava, Mango and Papaya on their terraces. Check our database of crops suited to terrace spaces.

Waterproofing Layer

You might require additional waterproofing if you plan to grow plants directly on the roof through soil beds. For plants grown in containers this may not be necessary. Waterproofing can cover either the entire roof or the areas where the plants are planted. Methods such as bituminized fabrics, asphalt, concrete admixture, fluid applied membranes can be used to waterproof the roof. Check the Service Directory for organizations that can assist you with waterproofing your terrace.

Drainage & Filter Layers

A drainage layer on the roof allows for excess water to drain and prevents water stagnation. Drainage on green roofs can be achieved using geo composites/geotextiles. A geo composite is a mixture of plastic drainage material with nonwoven geotextile fabric. The fabric holds the soil and moisture in place while the plastic design allows water to drain underneath and off the roof deck.

To avoid clogging of the drainage, a geo-fleece can be employed to sieve out sediments from plants. The filter layer or the filter fabric stops particles from settling into the drainage layer. Nonwoven filter layers are ideal for most surroundings. Rooftop / Terrace Garden Set Up consultants can assist you with this technology.