Q. Are pill bugs good for the soil? I dump kitchen waste into the soil and ended up having uncountable pill bugs.

A. Dumping kitchen waste directly into the garden is asking for major problems and pill bugs (Armadillidiidae) are just one of them. Pill bugs — also known as wood lice — thrive in the dampness produced by rotting greens, vegetable waste and fruit on which they happily feed and multiply. They will also devour healthy plants and their roots if/when they run short of kitchen waste.

Kitchen waste must be fully composted down before being used to enrich garden soil and feed plants. Composting — carried out in compost bins, pits or in specially-designated compost heaps — may attract a certain amount of pill bugs but these, and their eggs, are killed off during the natural heating-up process that takes place during the composting process. Stop dumping kitchen waste directly in the soil and start composting, please.

All your gardening queries answered here

Q. I live in Karachi and my grape vine leaves are turning brown and drying out, starting from the bottom upwards. There are only a few green leaves left on the top. The vine is in a pot. I increased watering but this didn’t help.

A. It is natural for grape vines to lose their leaves at this time of year as they are not an evergreen plant species. New leaves will begin to grow in early spring but, before this happens and while the vine is resting, it is important to prune it. Do this — using a pair of very sharp secateurs — by first cutting back the strong main stem of the vine to a point no more than approximately 12 to 18 inches above its roots. Next, prune back any remaining, long, thin stems to just three or four buds (these are the bumps from which new leaves will appear) above where it joins the main stem of the vine. This hard pruning is necessary if the vine is to produce strong, healthy growth next year. Also, and of extreme importance, is to cut off any flower buds that may form next year and in the year that follows. A grape vine should not be allowed to flower and fruit until it is at least three years old, by which time it should have developed enough root strength to produce good quality grapes. Permitting an immature vine to fruit badly reduces fruit quality and overall production. Grape vines need very little water over winter months when they are dormant, but their root system will benefit from a top dressing of old, well-rotted, preferably organic, manure/compost at this time.

Q. Can purslane and gotu kola be easily grown in Lahore?

A. Purslane thrives in Lahore as long as it receives water, on a daily basis, in hot weather. Its seeds are generally sown from mid spring to mid-summer and crops can be prolific. Gotu kola — botanical name Centilla asiatica — is an indigenous aquatic plant found in wetlands and besides rivers/streams in Punjab and some areas of Sindh. It can be grown on a garden scale if lots of water is given, but this plant is not recommended as it falls in to the ‘highly invasive’ category, thus having the potential to create major problems.

Q. I recently bought a Sohanjna plant from DHA, Karachi but my gardener says it is something else. It just gives yellow flowers. Are there different kinds of Sohanjna? How can I confirm whether my plant is real Sohanjna or not?

A. To the best of my knowledge and belief, Sohanjna (Moringa oleifera) or drumstick tree, bears creamy white flowers not yellow ones. There are many similar species in the genus Moringa. I have no idea which one you may have.

Q. Please recommend a good blog or website for learning about gardening here.

A. I suggest that you join one of the many Facebook pages dedicated to gardening in Pakistan and take it from there.

Q. Which culinary herbs and vegetables can be easily grown in pots and small beds in the Lahore climate?

A. Coriander, dill, aniseed, basil, thyme, sage, chamomile, nasturtiums, rosemary, chives, garlic chives, bee balm (Monardia) and many more herbs — each in their specific season — are suitable herbs for you to try. Most vegetables — providing pots/containers are large enough — can be cultivated, too, and I suggest you consult this column on the first Sunday of each month, for information about what to sow and when.

Q. I have noticed a lot of cobwebs on my okra plants. Can you kindly suggest a remedy? I reside in Karachi.

A. The weavers of these cobwebs are spider mites. These common pests can be eradicated by spraying the plants thoroughly with warm, soapy water (use a biological washing up liquid or unperfumed, mild baby shampoo), each evening for three to seven days, depending on how heavy the infestation is.

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, November 25th, 2018