Gardening with Wilson

Four gardening questions were given answers in the third and last instalment of the Root Awakening column for the month of July 09.

The first question was about the drying of leaf-tips in a rosemary plant. This is a commonly encountered problem in Singapore which is likely to be brought about by excessive soil moisture. The rosemary plant is a native of the Mediterranean region that is adapted to grow in a cool and dry climate. It can grow well in Singapore provided it is grown in a well-draining soil mix. To be on the safe side, it is best to grow a plant in an area that is sheltered from rain and still able to receive direct sunshine for at least half a day.

The second query asked why soft rotting spots were found on a leaf of an orchid. This problem can arise when leaves are injured by water constantly dripping on the same spot on a leaf. Cut away the affect part of the leaf using a sterilised pair of sectaceurs. Remember to sterilise it after cutting the infected leaf. It may be beneficial to seal the wound from further infection by pathogens by coating it with some fungicide powder.

The third question asked why an asparagus plant was found to be turning brown. In general, asparagus plant (also called asparagus fern) should not be over-watered and needs to be grown in a bright place with some filtered sunshine for at least half a day. Its roots should not be allowed to dry out. An asparagus plant can easily dry out when it is grown in too small a pot where its roots can be seen to come out from the drainage holes found at the base of the pot. In such a case, there is very little soil left to help retain water for the plant. Exceedingly low air humidity may also cause leaves to turn brown.

The last question asked where can one purchase white summer oil. White summer oil is fractionated petroleum oil that has an emulsifier added to it. Currently, the gardener may encounter some problems in trying to buy the product from local nurseries as the products sold are not explicitly labelled as ‘white summer oil’. One should look out for the product that comes with the tradename ‘Acalineum’. Please always follow the instructions given on the label of the bottle. Otherwise, do also check out the Materials Safety Data Sheet (MSDS) that can be found online for a similar product.