Three gardening questions were provided with answers for this week’s Root Awakening column. The first question dealt with the choice of fruit trees that are suitable for growing in a rooftop garden in Singapore. For this, I suggested some small fruit trees that are more rewarding to grow in pots which include the chiku, kedongdong, guava, jambu and starfruit. Grafted versions of the mango can also be considered. Another fruit plant to grow is the dwarf Cavendish banana. It is important that fruit trees should be located in a location where they are able to receive at least 6 hours of direct sunshine and soil that is kept moist at all times. Note the weight bearing capacity of one’s roof-top before populating the area with large pots of fruit trees.
The second question was about the choice of plants for a east- or west-facing growing location and the range would largely depend on the duration and intensity of sunshine that are available. If the area receives direct sunshine for at least 4 hours daily, one can grow a large range of plants which include flowering shrubs and vines and selected vegetables and herbs. Fruit trees can be difficult as they require longer duration of direct sunshine.
Note that many foliage plants need some form protection under such high light conditions to prevent foliage burn. They can be grown on the lower tier of your growing rack or between taller plants which can offer some shade from direct sunshine. I referred readers to grab the book entitled ‘1001 Garden Plants of Singapore’ published by the National Parks Board for the range of plants that one can grow in a balcony. The light requirement of each plant is indicated by an icon in the book.
The last question was about the lack of fruit set in tomato plants. This is a commonly encountered problem in Singapore. It is important to note that not all tomatoes will be rewarding to grow in Singapore’s climate. Only the smaller fruited cherry tomatoes seem to set fruits well here. Larger fruited ones usually experience poor fruit set as flowers tend to drop off without turning into fruits. To help pollination, it may be beneficial for one to perform hand pollination by using a fine paintbrush to brush each opened flower to help transfer pollen which will increase the chance of fruit set.
Note that the first few flushes of flowers tend to be aborted but fruit set should start soon after that.
