Can tiny home gardens host trees safely? Do tree roots attack foundations and cause cracks in walls? While all of us understand the need for trees in the urban landscape, many of us hesitate to plant trees in our home or apartment gardens fearing that the tree’s roots could attack the foundations or walls of our homes or compound walls.
True, trees with extensive root systems like the neem tree need substantial soil space. While it is not feasible to grow such large trees in tiny soil spaces, there are a host of trees with small root systems that can be grown even in one or two ft soil spaces alongside compound walls, and at locations even just three feet away from the building.
“Bauhinia (mandarai), creteva (mavalingam), shrubby cassias, ixora (vetchi) trees, muraya paniculata with its nice fragrant flowers, henna, dwarf mango varieties, gooseberry trees, lemon trees pomegranate trees, henna, native medicinal trees like the adathoda, nochi... there are quite many options to choose from. These trees can be grown for their shade, fruits, flowers, or just to keep the natural ecosystem alive in the city. We have to think of ways to bring back greenery to the city, rather than take lack of space as an excuse”, suggests Prof. D. Narasimhan, associate professor, Department of Botany, Centre for Floristic Research, Madras Christian College.
In the case of big trees like the neem which needs about 10 feet of soil surface between it and the building, construction of an underground concrete or stone barrier may be taken up, to prevent sprawling roots from reaching into the building’s foundation. And then of course, remember to plant the tree saplings deep enough. If you are going to plant the tree sapling at the surface depth, then of course, the growing tree’s roots have a higher chance of spreading around and reaching the foundations. “If you plant the tree sapling at the prescribed depth of three feet, the growing tree’s roots tend to grow deep into the soil and stay clear of the building’s foundation”, suggests horticulturist Hariesh Krishnamurthy. He recommends, “We need to plant the sapling after digging a pit about 2.5-3 feet deep. After planting, cover the pit with soil, leaving half to three fourth of the pit uncovered. Over a period of four months, the pit can be filled with sand and soil and brought to ground surface.”