Q. Summer is here and I would like to know the names of some heat-tolerant annuals which I can grow in my garden.

A. There are lots for you to choose from. Sunflowers — dwarf, medium, tall, single or double flowered in lots of stunning colours — portulaca, zinnia, celosia, amaranthus, cockscomb, coreopsis, gaillardia, cosmos, marigolds and tagetes all being prime examples.

Q. I have a dozen old eucalyptus trees in my garden. The neighbours are complaining that the eucalyptus roots are destroying their garden soil because I do not water the trees. If this is so, what should I do?

A. It is quite possible that your neighbours are correct: the roots of eucalyptus, a very thirsty tree species, travel for long distances in search of water but watering them at this stage isn’t going to change anything. Cutting down the mature trees and then killing their root systems isn’t something I would like to advocate — this is entirely up to you. Eucalyptus should never be grown in urban environments as, aside from consuming a frightening volume of water, the roots wreck underground pipes, tanks, house and wall foundations, footpaths and roads and the brittle branches can be lethal in stormy weather.

Q. When and how should bloodmeal be used in the garden?

A. Bloodmeal is just about the quickest acting nitrogenous organic fertiliser. Sprinkle one tablespoon per square metre in your flower / vegetable beds and immediately water it in, or dissolve one tablespoon full in eight to 10 litres water to give pot plants an instant boost. Apply every three months in garden areas that are under year round cultivation.

Q. To what extent is fishmeal good for plants and how should it be applied?

A. Fishmeal, high in nitrogen and trace elements, is slower acting than bloodmeal (see answer to previous question) and is best added directly to the soil two to four weeks before the area is planted. Used at the same rate as bloodmeal, it is an excellent source of plant nutrition and a good general soil conditioner too.

Q. There are tiny black bugs on my chilli plants in Multan: the plant leaves and flowers have withered away. How can I get rid of these bugs and get chillies in bulk?

A. The bugs are either aphids or black fly, both can be easily controlled at the first sign of infestation by spraying warm soapy water in the evening — spraying should be done under as well as on top of the leaves — or by spraying with garlic water, chilli spray or a neem-based organic spray. At this time of the year it would be best if you completely remove infected plants (dispose of them in a rubbish bin away from the garden, please) and start new ones from seed. Use top quality soil / organic compost and feed the plants once a month for heavy crops.

Q. How can I grow and care for a Thuja (morpunkh) tree in Larkana?

A. Thuja flourishes in most soil types as long as it receives adequate and regular water: moisture-retentive mulch is highly beneficial in hot weather. Young trees are to be found in most nurseries at relatively low cost. If pot-grown plants are purchased they can be transplanted at any time of year except during high summer but bare-rooted plants (dug directly out of the soil at the nursery) should only be bought and transplanted during the winter months. They make excellent specimen trees or can be planted three to four feet apart for a fast growing hedge. The only problem — as long as watering requirements are met — in your location could be sunburn from hot winds. A trial run with just one or two trees is recommended, for at least a year, two years if possible, before you invest in additional ones.

Q. I planted potatoes in a pot on my Karachi rooftop. I buried the plant when it became a little bit tall as I was told that this would increase the yield but I only got two really tiny potatoes. What did I do wrong and how can I achieve a bumper organic crop?

A. A column dedicated to growing potatoes is scheduled to appear on these pages in the not-too-distant future: please wait for this as it will answer your query in full.

Q. Can tomato plants fruit in summer in Karachi?

A. Yes. In fact tomatoes can, with care, fruit all year round in Karachi.

Q. I read about comfrey in your column. Kindly send me the exact locations where it is planted in Islamabad and Murree.

A. Your interest in comfrey is appreciated but it is being grown by private individuals in these locations: it would be an unforgivable breach of their personal privacy to provide their home addresses.

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, April 23rd, 2017