Q. I am having a problem with orange trees planted in my garden in district Attock, Punjab. They were planted in 2013-14 and about two-thirds of them survived and started fruiting. However, every year some of them die. Initially, their leaves turn yellow, become smaller in size and then the tree dies. I am unable to find a cure. Soil tests showed phosphate: 2.30-7.02, nitrate:19.22 and potassium: 52-70. Iron: 6-1.5 and soil pH is 8.07-8.17. Gypsum and ammonium sulfate were recommended and I have been using them for two years but the trees are still dying. Last year, I gave them half kilo urea, half kilo DAP and one kilo manure to each tree. Most trees are green and healthy but still there is sudden decay and dying. What can I do?

A. The soil in your garden is too alkaline for long-term cultivation of the oranges. Soil salinity has become a massive problem in some areas of Punjab and is continually increasing. Applying gypsum — which is also a salt — is only useful if you have copious amounts of fresh water, not brackish, to thoroughly soak the land with. The gypsum then acts to breakdown existing salts in the soil, leaching them out in to a suitable drainage system which, given the circumstances, you are unlikely to have. Ammonium sulphate is a chemical fertiliser which is said to help plants survive stressful situations. It is possible that your orange trees will continue to slowly die off and, when they do, I suggest replacing them with jamun, ber, guava and imli, all of which will tolerate the soil conditions you have.

Q. Please give easy to follow instructions on how to make homemade sprays such as garlic spray and chilli spray.

A. Put a quarter kilo of unpeeled garlic cloves in a pan with one litre water. Bring to the boil; simmer for 15 — 20 minutes. Remove from heat. Leave to stand for 12 — 24 hours. Strain through fine mulmul or cotton cloth and spray the resultant liquid on to pest-infected plants. Spray each evening, for three to six days or until pests are destroyed.

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For chilli spray, take a quarter kilo of red chillies and, protecting your eyes, face and hands, either chop them finely or put through a blending machine. Put the resultant mush in a large container, add one litre water and let stand in full sunlight for at least 48 to 60 hours. Strain and spray on affected plants. Wear glasses and gloves when spraying this and do not spray when there is wind. Repeat every two to three days until the pests have gone. Spraying is best done around sunset when bees and other beneficial insects have gone to bed for the night.

Q. Please give some general tips about caring for lemon trees.

A. Lemon trees dislike too much water: water lightly just once a week in winter and twice a week in summer. Spread a two-to six-inches deep (depending on the size of the tree) layer of fully rotted down, organic compost around the base of the tree but not touching the trunk, every six months. This will keep the tree well-nourished and happy.

Q. We are trying to grow our plants organically and need to know if the following would compromise this in any way: vermicompost, cocopeat, bone meal, blood meal, zinc, potash.

A. Vermicompost is made by worms living inside purpose-built wormeries in which they are fed on organic waste. As long as no adulteration has occurred further down the line, vermicompost is fine. Cocopeat is fine and so are bone meal and blood meal if they are pure products — check labels carefully and buy organic if you can. Potash is, basically, fire ash from burning wood, dry leaves or other plant material. Make your own, if this can be safely done or buy an organic brand. Zinc is a naturally occurring micronutrient but there is no need to add it to your soil unless comprehensive soil testing indicates its absence, as too much zinc is poisonous for plants.

Q. I planted three Moringa oleifera and a gulmohar in a green belt adjacent to my house in Karachi. The gulmohar has rapidly grown to twice the height of the Moringas and is blocking their light, plus, the gulmohar has an odd shape and look and it may not be a gulmohar at all! Do you think I should remove this strange tree and replace it with another Moringa and is now a good time to do this? I left a gap of five feet between each Moringa tree — is this enough?

A. Moringa oleifera trees are best planted 10 feet apart, just five feet is not enough for strong, healthy growth. If you are going to move any of them, providing they are still smallish, then now is a good time and it is also a good time to plant more. Unless the strange tree becomes excessively problematic, why not simply let it be? Trim it back if necessary but don’t forget that it, too, has the right to live.

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, December 22nd, 2019