Q. Most of the sharifas (custard apples) on my tree grow up to a point and then turn black and hard. The few that remain green do ripen and are very sweet. The tree has been bearing fruit since the last eight years and this has never happened before. There is no change in the surroundings of the tree. I live in DHA, Karachi and am not close to the sea. Please advise what I should do.

A. The sharifas are under attack from a minute wasp species: it buries into the fruit and lays its eggs there, which causes a fungus that mummifies the fruit. The only way of dealing with this is to remove all infected fruits from the tree, and any that have fallen on the ground. Dispose of them in the garbage bin to break the wasps breeding cycle. Since there is no effective spray available for this problem, tree and orchard hygiene is the only possible way forward.

Q. We live in PECHS, Karachi and have a problem with our sharifa tree. This season, over half of the fruit turned grey and as hard as cricket balls, while the remainder was perfectly fine. What is the cause and how can it be prevented from happening again?

A. Please see answer to the question above.

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Q. I am in Kalat, Balochistan and have an orchard of apples, peaches, apricots and cherries. I recently came across goji berries and have managed to obtain some seeds, but I have no idea what kind of growing conditions and care they need. Can you advise, please?

A. Goji berries or Lycium barbarum, are known as a ‘super food’. Indigenous to Pakistan, they can be found growing wild in the Indus delta region, as well as in the northern areas. They tolerate high and very low temperatures, prefer a soil that is high in organic material, and need lots of water to grow strongly and produce heavy crops of the nutrient-rich berries they are known for. These sun-loving shrubs can reach a height of over 10-ft and a width of 4-5 feet. They have long, thin, supple branches and it is a good idea to grow them on wire like grapevines. They can be propagated from seed sown in early spring, just when temperatures are beginning to rise. Seed-grown plants can take three years to begin fruiting, so goji berries are generally multiplied from cuttings, taken anytime between March and September, which root quickly and begin to fruit the following year. A very easy plant to grow as long as regular watering is maintained.

Q. Which fruit can be grown in the winter season in Hayatabad, Peshawar?

A. Presumably, you want to know which trees to grow to provide you with fruit over the winter season and, if this is the case, pomegranates, oranges, persimmons, lemons and loquat meet your requirements. Alternatively, if you want to know which fruit trees you can plant over the winter period, the answer is just about everything that your local nurseries can supply and they should have fresh stocks soon.

Q. I have a 5-year-old orange tree in my garden in Harbanspura, Lahore. It is about 10 feet high and started fruiting a year after planting it. The tree gives a good number of oranges but, since the last two seasons, the oranges are falling off while they are still green. A gardener visits twice a week to look after our plants and trees. A nursery man advised that the tree be fed with potassium, which was done, but it had no benefit. What can be done to resolve the problem?

A. Orange drop can be caused by a number of things. Either the crop is too much for the tree to cope with, or there is too much or too little water or lack of nutrients in the soil. If lots of baby oranges form, thin them out, using sharp secateurs to remove excess fruits, to a distance of about 6 inches apart. This results in large, top-quality fruit. Ensure that the soil around the tree is kept damp, but not wet, at all times right from blossoming to harvesting of fruit and never ever allow the soil to completely dry out. Apply a deep mulch of well-rotted, preferably organic, animal (not poultry) manure around the base of the tree — but not in direct contact with the trunk — in February and again in September. I suspect that your gardener is, as gardeners here tend to do, flooding the tree roots now and then, instead of taking the little and often approach, which is more time-consuming.

Q. I live in Lahore and have an avocado plant that is over a year old, but its leaves are turning brown. I consulted friends and followed their advice of giving more water, spraying the leaves with a chemical foliar feed and applied a dose of leaf manure around the plant base. The results are not encouraging. What shall I do now?

A. There are two possible reasons for avocado leaf browning: saline soil conditions which avocados hate and/or exposure to drying winds. If the soil is saline, there isn’t much you can do at this stage. But if wind is the culprit, you will need to erect some form of wind protection to help the tree through its first five or so years of growth, and keep your fingers crossed that it becomes strong enough to survive, without protection, once it reaches maturity.

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 28th, 2021