Q. I live in Malir in Karachi, near the airport. For the last few years, I have been planting a few fruit trees every year. So far, I have planted lemons, dates, custard apple, mango, pomegranate, bananas and figs. Initially the harvest is good but, after that, there is nothing but problems. For example, custard apples turn black, lemon tree sheds flowers and the leaves dry out. What remedy would you suggest?

A. You certainly have a problem on your hands and I suspect that increasing soil salinity is at the root of the problem. Once a highly fertile growing area, Malir has been going downhill for years now as the combined problems of soil salinity, brackish water and chemical pollution wreak havoc on local growing conditions. I suggest that you contact your local agricultural department and arrange to have both soil and water tested. Remedial action should be based on the results of these tests. Please feel free to contact me again once you have these all-important results in hand.

Q. In railway colonies and other old localities of our cities, hedges were grown for privacy, and to mark the boundaries of residences. Sadly, these and other hedges have been replaced with brick walls. To help me reverse this unfortunate trend, please suggest some plant varieties that can be used to make thick hedging, and for general landscaping in Lahore.

A. Brick walls do not look anywhere near as nice as shrubs but people have switched to them for security reasons. Using walls to support thorny bougainvillaea or climbing/rambling roses is one way of bringing greenery back into the daily lives of city and town dwellers. Otherwise, shrubs that can be used as hedging include lantana, clerodendron, tabernaemontana/chandni and murraya exotica/kamini.

All your gardening queries answered here

Q. When does it become too hot to plant trees in an open area, in Lahore? The tree species I’m looking at are varied, but primarily sukh chain [Indian beech], and neem trees. Till what month can saplings be safely planted, given that adequate water supply is available?

A. Tree planting time is already over but begins again on the arrival of the monsoon. Mark the specific planting spots you have selected and get on with the task of preparing planting holes, a month or so before actual planting time arrives. Preparing planting holes in advance allows time for any necessary soil adjustments and additions of manure/fertiliser (remember to keep it organic please) to settle into place before the trees go in.

Q. How can I encourage my garlic lilies to flower? I have had the plants for two years, and they have lots of healthy leaves, but no flowers at all.

A. Tulbaghia violacea/garlic lilies are natives of South Africa and, like many other South African flower species, need lots of sunshine if they are to bloom. Without enough direct sunlight, they will refuse to bloom. Unlike drought-tolerant South African plants, this particular species also requires damp, not wet, soil conditions during the weeks before it is expected to flower, in spring. After flowering is over, regular watering is not so important. I hope this helps.

Q. I want to make a border of hollyhocks to hide the plain bricks of the boundary wall edging our garden, just outside Rawalpindi. What is the correct time to sow the seeds, and what distance apart should the resultant plants be? How should the soil be prepared and how long will it take for them to begin flowering? This is going to be a permanent feature and I am so excited to do this.

A. What a glorious task you have set yourself! Seed can be sown from the end of July through until the end of September, for flowering the following year. Protect the seed trays/seed bed from heavy monsoon rains and from direct sun when temperatures soar. Firmly fixed green shade netting is your friend until the seedlings are fully established. Plant out at 3ft apart in well-prepared soil that is rich in organic matter/compost. There are annual, bi-annual and perennial varieties of hollyhocks, so please choose your seeds with care.

Q. My firecracker plant is not growing well and not flowering. What can I do?

A. Russelia equisetiformis/firecracker plant is such an easily grown shrub that I am surprised you are having problems. Native to Mexico, this beautiful shrub needs lots of sunshine and, once established, very little water to thrive and put on its spectacular show of blooms. I suspect that you may have planted it in a shady place. If so, you need to move it into the sun, but wait until during the summer monsoons.

Q. Can sesame seeds be grown, in pots/containers on our rooftop in Islamabad? How many sesame plants will be needed to produce at least 5kg of seeds?

A. Yes, they can. I have absolutely no idea how many plants you need to obtain a harvest of 5kg, but certainly far, far more than your rooftop has space for.

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, EOS, May 8th, 2022