Azure borage
Q. I want to create a rooftop garden using plastic containers measuring three feet by three feet and three feet high. I am worried about the weight once they are filled with a mixture of sand, clay soil and manure. Can I use polystyrene (thermopore) in the soil mix to reduce the weight as I do not want the roof to come crashing down?
A. You can, but its weight must also be considered. It is always best to seek the advice of a structural engineer before investing in a rooftop garden or, at the very least, to ensure that planting containers/pots are carefully placed on top of the strongest sections of the roof; these usually are load-bearing beams which should have been designed to take a huge amount of weight. The use of polystyrene/thermopore renders edible produce un-organic but this, I guess, is the least of your worries.
Q. I planted an Amaltas in my Islamabad garden about four years ago. It gets plenty of sun, has grown quite tall and appears healthy but hasn’t flowered yet. Please help.
All your gardening queries answered
A. Amaltas — botanical name Cassia fistula — can be finicky about coming into bloom, either deciding to put on its first floriferous show at the early age of two to three years or hanging on until the ripe old age of five to six years. It sounds like yours is waiting, so please be patient and wait, too. Tip: Now that it is fully established, do not water more than twice a week in summer and once a week in winter; overwatering, in this case, results in foliage not flowers.
Q. Can I grow borage, chamomile, chives and basil in Karachi? I brought the seeds from Australia but have no idea how or when to sow them.
A. All of these can be sown in autumn or, you’ll be pleased to know, right now. Sow seeds at a reasonable distance apart, just under the surface in good quality, well- draining — preferably organic — compost in seed trays or pots. Keep in a sunny spot, water daily but do not drown them, and germination should be fairly rapid. Once seedlings reach approximately two to three inches in height, carefully transplant them into either prepared garden ground, preferably a spot where they get no more than four hours direct sunshine as temperatures will soon be climbing, or into a suitable array of pots/containers to be placed here and there. Borage seedlings are quite large and fast-growing and easy to plant out individually, and the same goes for basil. But both chamomile and chive seedlings are finer and best planted out in small clumps. Basil, being a sun lover, will take more hours of sunshine per day than the other herbs mentioned here.
Q. Can the following seeds be grown in Karachi: Bonsai blue Mestasequoia, Bonsai Azalea, Bonsai pink Camellia, pink rose tree, Japanese flower seeds, Phalaenopsis orchids and white wisteria seeds?