Q. I have germinated six Graviola saplings in pots inside my Seaview apartment in Karachi. The problem is that I do not know how to care for them or even if they will tolerate the high salt in the atmosphere and in the soil here.

A. Botanically known as Annona muricata and more commonly as Sour sop, graviola or guanabana, this close relative of Custard apple, (Sharifa in Urdu) Annona cherimola botanically, is already being successfully cultivated in home gardens in various locations including Karachi, in Sindh. As sharifa does fine in Seaview, provided wind protection is given, so should graviola as long as it is never allowed to become waterlogged as this it will not tolerate. Growing into a small to medium sized tree, graviola produces a spiky, green fruit with a creamy ‘mush’ inside when ripe. Very high in Vitamins B1, B2 and Vitamin C, it has, in recent years, been credited as a powerful cure for cancer but these claims are still under scientific investigation.

Q. We are planning to build a house and create a garden just outside Islamabad. Will Passiflora be suitable to grow over a boundary wall and what kind of fruit trees do you recommend for cultivation in a west-facing area measuring 60ftx10ft? We also intend to grow vegetables in a south-facing location measuring 35ftx10ft and would appreciate advice on this. Although we are ardent gardeners, we are moving up from Karachi and not yet familiar with Islamabad climate.

A. Passiflora will be perfect for your boundary wall but do try to find the edible fruited variety rather than, glorious as they are, purely ornamental ones. Suitable fruit trees, provided you have plentiful access to irrigation water, include: oranges, lemons, grapefruit, kumquat, sweet lime, apricots, peaches, plums, nectarines, persimmons, mangoes, loquat and many others. You will soon adapt your gardening knowledge to the Islamabad climate and for ongoing advice, please keep your eye on this column.

If you know what to plant and when, you are moving in the right direction; the rest will be easier

Q. I obtained seed for Dioscorea batatas last autumn and planted some in pots on our terrace and others in the garden near a tree. I was very disappointed when nothing came up over the winter and reused the pots and garden area for other things. To my surprise though, in early summer I noticed some strange vines coming up in odd places and, after searching on the internet, identified them as Dioscorea batatas. They have now grown very well but when I search for detailed information on how to care for them, using the name batatas, all I find is confusing things about sweet potatoes. I need to know if they have another name, if they flower, if they are evergreen, if they need support to climb up, what depth of soil is best for them and when to harvest the tubers? I live in Islamabad.

Dioscorea batatas.

A. Searching for just batatas will be, as you have discovered, confusing. The full name is Dioscorea batatas or cinnamon vine and you should search for this. These are warm to hot weather climbers and can attain a height of 15ft. They can be trained up strong twine, trees or other suitable support and will, during the summer months, bear racemes of small, cream coloured, flowers with the slight fragrance of cinnamon. After the flowers die back, seeds form in the leaf axils and the underground, tuberous root — this is a type of yam — will fatten up.

The tubers measure, on average, six inches to 36 inches in length, are eaten like yams / potatoes and store, in or out of the ground, for a very long time. The tubers are harvested, over the winter months, after the vine has died back. They flourish in good quality, deep, stone free, well draining soil, enjoy sunshine and are generally trouble free.

Q. I am a student and reside in a flat which has both a balcony and a rooftop. I want to start growing vegetables and flowers in these places and desperately need advice about doing this from scratch. I also need to know where to buy what is needed to get going.

A. Having written on this subject many times in the past — and no doubt there will be more such columns in the future — I suggest that you go through some back issues of this magazine on the Dawn website for the information you request and, of course, keep on reading this weekly column too. You can purchase pots, soil/compost, tools, seeds, etc. in gardening supply stores and at some nurseries.

Q. I live in Karachi and would like to know how to care for the lemon and pineapple plants I have purchased, please.

A. Lemon trees enjoy plenty of sunshine, well draining, good quality soil/ compost and should be kept watered but not overly wet. Pineapple plants also require sunshine, top quality, well draining, soil/compost which has a high iron, potassium and mineral content — they enjoy organic seaweed meal, regular watering and lots of tender loving care.

Q. Establishing a pot garden on the roof of my five marla house in Islamabad is my goal. I want to grow something to earn money. My time is limited so I wish to do this with minimum effort. Can I grow mushrooms, cacti, costly fruits and vegetables or some other pleasing plants, which will bring a good return, on the roof?

A. Mushrooms cannot be grown in the open air here in Pakistan so are not at all suitable for what you want to achieve. Cacti, especially if you can cultivate unusual species, are a distinct possibility but do, like all ornamental plants, take time to reach a saleable size. Fruit and vegetable cultivation needs lots of input (time and material wise) and may not, therefore, meet your needs. I suggest that you do some in depth research into both plant and marketing matters.

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

Published in Dawn, Sunday Magazine, October 26th, 2014