Q. Aphids and spider-mites have suddenly become a major problem in my garden in Islamabad. They are decimating my plants. I keep trimming the affected leaves, have tried spraying chilli-garlic water and even used garden insecticides but nothing seems to work as the pests hide under the leaves. What should I do?

A. Aphids and spider-mites increase rapidly as soon as temperatures begin to rise which is why you are experiencing problems now. Aphids can damage plants or even kill new growth by sucking on the soft, tender tissue. Stick to spraying with chilli/garlic water or plain, warm soapy water each evening for seven days and then cut down to every other day for another week, but totally avoid using any chemical sprays at all. This spraying schedule will eradicate the pests but only if you spray underneath as well as on top of the leaves: As you have already noticed, pests hide under the leaves so unless you spray under the leaves too you cannot wipe them out. Irrespective of what you spray, the correct procedure is essential for success.

Q. I have been trying to increase my plants by taking cuttings from healthy specimens but all my cuttings dry out and die. What is the way to do this successfully in Islamabad? Everywhere on the internet rooting powder is recommended but I do not think that it is available here. Would it be better to try layering and, if so, how is this done and at what time of the year?

A spicy home-made spray can help you get rid of some common plant pests that typically hide on the undersides of leaves

A. How and when to take cuttings often differs from plant species to plant species, the same with layering. I have made a note to dedicate a column to this subject in a few weeks’ time. Please be patient until then. Rooting powder is available in some seed stores so you need to shop around for this although, as I will include in the column, there are alternatives.

Q. I have observed that most nurseries grow plants only in sand and the growth is lush. What is their secret as sand does not contain any nutrients?

A. I beg to differ: nurseries mix river sand/river silt with manure and use this as a growing medium for their plants. It may look like sand but is not. River silt is especially rich in nutrients and can be used alone with excellent results.

Q. I was gifted a huge bulb of Amarcrinum (Amaryllis x crinum) a number of years ago. It is growing well in a pot, has produced many offshoots but has completely failed to flower. What could be the reason?

A. Shortage of sunlight could be the reason as these bulbs need at least six hours of direct sunlight a day to ripen fully and thus encourage flower formation. In this they differ from both of their parents which happily flower with less sun and even in partial shade. Alternatively, the bulb may need additional organic humus/compost added to the soil mix in the pot. Resolve these two issues and then keep your fingers crossed and wait. The bulbs can take as long as seven to nine years before gaining enough strength to flower but ... the wait is worth it.

Q. Do the following plants have perennial potential in Lahore: Laurentia-Isotoma axillaris, Rhod­ochiton atros­an­gu­ineum and Catananche caerulea?

A. Laurentia-Isotoma axillaris is unlikely to survive as a perennial in Lahore but does well as an annual. Rhodochiton atrosanguineum (purple bell vine) is an annual not a perennial climber. Catananche caerulea (Cupids dart) stands a fair chance of surviving as a short-lived, self-seeding, perennial providing that the site is relatively sunny and very well-drained at all times.

Q. I want to improve drainage and aeration of my soil mix in pots. I currently use 50 percent river soil and 50 percent well-rotted leaf compost and have a problem with root rot. Will adding more leaf compost, perlite or cocopeat help?

A. Try a mix of 35 percent each of river soil, leaf compost and river sand. River sand will assist drainage and alleviate root rot problems. Leaf compost, cocopeat and even, to a lesser degree, perlite are water retentive.

Q. I tried growing China lotus from seed. I sprouted it in a jar but the tiny leaf turned brown and died when the shoot was just three to four inches long. I want to try again but would like your advice first.

A. You started out correctly but then went wrong. Sprout the seed as before. Immediately after the first leaf begins to form carefully transplant it into a four- inch diameter clay pot of soil and place the pot in a larger water-holding container. Slowly adding enough water to cover the planted pot and seedling so that there are two additional inches of water (this mimics the pond scenario). Leave it in a well-lit place until the seedling develops into a strong plant. It can then be planted out in a pond or in a large, water-holding container of some kind and left to mature and eventually to flower.

Q. Where can I get water lily plants?

A. Check your local nurseries or search online for a source of seed. The seed should be grown as mentioned in the question/answer above.

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

Published in Dawn, EOS, March 26th, 2017