Q. I grow a variety of plants, in pots, on my rooftop in Karachi. Jasmine, motia, roses, aloe vera and mor pankh are all doing quite well and I now want to add some big-leaf varieties to provide more shade and oxygen. What would you suggest, please?

A. It is wonderful to know that you are having success with the plant varieties you have named, and you are to be congratulated on this. As long as you can provide adequate protection from hot / cold winds and from the direct rays of summer sun between the hours of 11am and 4pm, then the following species may be considered: Monsteria deliciosa, money plants, Ficus elastic as long as you do not allow it to grow too tall but encourage it to grow in bush form instead, Maranta with very pretty leaves, Murraya exotica — Kamni and Jatropha. If you have any walls to utilise — or can provide firmly fixed trellises or other support, then there are numerous climbers and creepers — some, such as grape vines and edible varieties of Passiflora having the bonus of fruit production, would be a good addition. If direct, noon time sun is unavoidable, you could also have ‘fragrant ‘Brugmensia’, some dwarf varieties of date palm and other wind tolerant palms — the edges of some palm species, Kungni palm for example, are susceptible to wind-burn.

Q. Does Karachi have a suitable climate for cultivation of indigo plants? The botanical name is, I think, Indigofera tinctoria and the blue dye obtained from them is used in Sindhi ajrak. I know that the plant is currently grown in the interior of Sindh and also in Multan area, but do not know if the coastal climate of Karachi is suitable.

From climbers and creepers to shrubs and palms, there is quite variety of plants for rooftop gardens

A. Worth a try but only if the plants have a good degree of protection from direct sea wind.

Q. It is said that liquid fertiliser may be prepared by dissolving cow dung. Can the same be prepared from buffalo dung and, if so, then how?

A. Yes, of course, it may be; additionally, horse, goat and even camel dung may be utilised as well. It is easy to prepare: suspend a jute or similar type sack / bag full of dung in a drum or other large container of water. Tie the bag of dung (the size of bag and volume of dung depending on the capacity of the water container) to a strong rod / pipe laid across the top of the drum, hanging it so that it is completely submerged in the water. Stir around morning and evening for 10-14 days and then remove the sack / bag, and use the liquid fertiliser on your plants after diluting it one measure of liquid fertiliser to 10 measures of water. You can add the used manure to the compost heap / bin.

Q. My favourite cactus plant is dying because of lack of water. Can you please tell me of any natural ingredient to save it? I live in Karachi.

A. Having given long and serious thought to your query I, unfortunately, remain at a total loss and, therefore, must ask you for additional details. Why do you feel the cactus is suffering from lack of water as, if this is the case, all you have to do is give it a drink? Is it in a plant pot or growing in the ground? What is size, species, and age of the cactus, and what are its visible symptoms?

Q. Living in rural Sindh a common problem we face when we purchase seeds is that the seed packets do not have any sowing instructions, do not advise on sowing time and give no expiry date. Will you kindly suggest a test, if any, to verify whether the seeds are alive or not?

A. I sympathise with what is an all too common problem, one which seed-sellers need to solve, as so many gardeners face this problem on a regular basis. Testing seed viability — to see if a seed is alive or not — depends on the species of seed involved but, for commonly sown vegetables / flowers / herbs, sprinkle maybe half a dozen seeds on a saucer / plate of moist cotton wool, place it in direct sunlight, keep moist and germination, if any, will happen quite fast. Otherwise sow just a few seeds, as per usual, in a plant pot / seed tray of good quality compost, care for them and wait and see if they grow. If they do, then sow the rest of the seed as normal — if not, go back to the seed store and request, without getting angry, for seed replacement.

Q. Can a plastic bag-grown plant, with flower buds or in full flower, purchased from a local nursery, be transplanted or repotted?.

A. Transplantation of any flowering plant, when in bud or in full bloom, is not recommended unless, that is, they are purely seasonal varieties — such as pansies, petunias and similar flowers which nurseries grow, in bulk, for the express purpose of gardeners buying to plant out in seasonal beds / containers.

Please continue sending your gardening queries to zahrahnasir@hotmail.com. Remember to include your location. The writer does not respond directly by email. Emails with attachments will not be opened.

Published in Dawn, Sunday Magazine, May 8th, 2016