Q. Conocarpus is spreading like wildfire in our country. I came to know that it is harmful for our health and for the environment too. Please explain the exact side-effects it has.

A. The subject of widespread planting of Conocarpus erectus in Pakistan is a very touchy one indeed, though I am sure someone is bound to disagree. As you quite rightly observed, there are two problems associated with this species.

On the health front, Conocarpus erectus or ‘Button Mangrove’ as it is sometimes called, is wind pollinated (as against bird /insect pollinated) and as with all wind-pollinated species, produces an incredible amount of pollen when in flower. This means that when planted in extremely large numbers, the pollen count in the surrounding localities goes through the roof. Very high pollen counts, irrespective of the actual plant species involved, are known to trigger serious allergic reactions in many people.

On the environmental front, Conocarpus erectus is not an indigenous species but originally came from Florida in the US. It is globally recognised that this species has the potential to be ‘invasive.’ This means that it multiplies rapidly, adversely affecting — and in extreme cases even killing off — indigenous plant species. Furthermore, indigenous wildlife — such as bees, butterflies and birds — basically depends for survival on indigenous plant species not on introduced foreign ones which may not suit their feeding / breeding requirements.

From both health and environmental points of view, instead of opting to plant millions of Conocarpus erectus, the ‘powers that be’ should have planted a regionally suitable mixture of indigenous species so that both health and environmental balances would have been retained. The bottom line is that the Conocarpus erectus story is a sad rerun of the horrific ‘Paper Mulberry’ fiasco in Islamabad.

Q. Is it okay to dunk small pots of flowers in a tub of water rather than using a watering can?

A. Not really. The idea is to water just the soil not the plant in its entirety.

Alien species can have harmful effects onhuman health and the environment

Q. Keeping in mind the climatic conditions in Larkana, when is the best time to plant fig saplings? What special care is needed for them to flourish and from where can I obtain them?

A. January and February are the best months for planting fig saplings in your locality. Figs produce best in poor to medium soil. They produce excess growth and leaves instead of fruit in rich soil. They do especially well in hollows in rocky land where the spread of their roots is naturally restricted. This enforced root restriction encourages them to fruit which is why, in some parts of the world, they are cultivated in purpose-built concrete tanks. They need a reasonable amount of water when developing fruit but heat and dry weather is needed for the crop to fully ripen. If your local nursery is unable to supply saplings, ask your local agricultural department for advice on where to source them.

Q. How should we know that soil needs re-balancing?

A. When plants display nutrient/mineral deficiency and do not grow as nature intended them to do.

Q. What fast-growing, shade trees, preferably with flowers, are suitable for Bahawalpur District?

A. You may like to try the following: Erythrina indica (Indian coral tree), Peltophorum ferrugineum (Rusty Shield Bearer), Pithecellobium saman (Rain tree), Cassia marginata (Red cassia), Cassia grandis (Pink shower) or Poinciana regia (Ghul mohr) although the latter two species are slower growing than the former ones.

Q. I want to plant carnation seeds. In which month should I do this and how should I care for them?

A. Presuming that you are in Karachi, carnation seed is usually sown from mid-August to the end of September. Seed-sowing compost must be of good quality and have excellent drainage: carnation seedlings/plants quickly die if they get water-logged.

Sow the seed, as thinly as possible, just under the compost surface. Place in a partially shaded location, protect from rain, water very lightly and be patient. Germination takes from two to six weeks. Seedlings are brittle — once they are large enough to transfer to a pot, handle with care. Just one seedling per 10-inch clay pot of well-draining, sandy soil is ideal.

Q. I long to grow lavender in my garden. Where can I get the plants or seeds?

A. Lavender seeds can occasionally be found in garden-supply stores over the autumn and winter months. A few nurseries stock young plants in the winter and very early spring but as you have not mentioned your location, I am unable to guide you further.

Q. Can almonds be cultivated in the sandy area of Thal, District Khushab?

A. Sadly this is not a suitable growing area for almonds; the extreme summer temperatures would burn them up.

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, Sunday Magazine February 12th, 2017