Q. I used to water zinnias from above with the intention of keeping the leaves clean from dirt but I recently read that they should only be watered from the roots and that leaves should be kept dry. I think I have killed my zinnias. Is watering from above the reason this happened?

A. There are many ways your zinnia plants could have died: watering them from above is certainly one of them.

Q. I have two lovely terraces on both sides of my lounge in Lahore. I really want to grow a grapevine on the iron structure as a canopy but am afraid that honeybees and yellow jackets would be a problem. I also want to grow jacaranda and white clematis — unless you can suggest some other fragrant vine with white or lilac flowers — on the terrace.

Your gardening queries answered

A. Your plans sound delightful. Grapevine is an excellent idea for the canopy. Don’t be afraid of honeybees as they will not harm you unless you interfere with them, simply ignore them as they go about their business and they will ignore you. Yellow jackets are a different matter though: they will be attracted to ripe or spoilt fruit. The most effective method of keeping them away is to harvest the fruit as soon as it is ripe and to keep the vine free of spoilt/damaged fruit by cutting it away as soon as you see it. The pluses far outweigh the minuses so stick with a grapevine please. I think that you mean wisteria vine rather than jacaranda which is a tree but do ensure that your wisteria is a fragrant variety – as not all of them are. The same goes for clematis. Both of these vines will be glorious when in bloom but, in our climate, they bloom for a very short period of time. You will get a much longer show from white jasminium, white beaumontia grandiflora, lilac or white passiflora.

Q. Are urea and sulphate of potassium organic fertilisers?

A. Urea is synthetically produced, therefore not organic. Potassium sulphate is marketed in both organic and non-organic forms. Please read all information on the packet/sack to ascertain which of these two categories a particular brand falls into.

Q. How are bottle brush trees propagated? Is it done through seeds or cuttings and is the climate in Hyderabad suitable for them?

A. Cuttings, approximately six inches long, are taken from semi-mature wood in early summer: all leaves on the bottom half of the cutting should be removed. They are easily grown from seed, are sown in spring/early summer and are suitable for your locality.

Q. Is it possible to use mulch in pots/containers? If it is necessary to remove three to four inches of soil to make space for mulch in pots/containers, how can this be done without damaging plant roots.

A. A shallow layer of mulch may be used in pots/containers, the depth of the mulch corresponding with the existing space between the surface of the soil and the rim of the pot/container only.

Q. I want to establish a vegetable and herb garden in my house in Clifton, Karachi. The problem is that I know absolutely nothing about gardening but I am very keen to learn. Can you suggest a teacher/mentor please?

A. Get in touch with your local horticultural society and begin to attend their meetings. This way you will begin to learn, plus, will meet many people who will be happy to share their knowledge and experience with you so that you can, in time, achieve your goal. Good luck!

Q. During these hot days of summer is it necessary to use warm water when preparing soapy spray. Doesn’t this harm the plants?

A. It is even more important to use warm water in the summer than it is in cold weather. This warm water is just that — warm, not hot. Very hot water would obviously harm plant leaves. Warm water in warm/hot weather doesn’t cause leaves to go into a state of shock as they are already warm, plus, warm water dissolves the soap which cold water does not.

Q. I live in Lahore and want to grow olive trees in my garden. Where is the best place to get them from?

A. Please contact the University of Agriculture in Faisalabad for the best advice on the olive variety recommended for your location and from where to obtain it. Olive saplings are usually available for transplanting from mid-winter until very early spring. You can also try an internet search for one of the recently-formed olive growing associations in Pakistan.

Please continue sending your gardening questions to zahrahnasir@hotmail.com. Important: remember to include your location. The writer does not respond directly by email. Emails with attachments will not be opened.

Published in Dawn, EOS, June 11th, 2017