Q. Like a lot of parents in Lahore these days, I am freaking out because of the alarmingly dangerous air quality. Smog has become a public health hazard, but, unfortunately, it isn’t being tackled as it should be. So the onus is on individual households to deal with the problem on their own. I have already purchased air purifiers and am trying to minimise my kids’ outdoor activities as much as possible. I read somewhere that there are a variety of indoor plants that can help improve air quality. Can you please guide briefly about this?

A. There are quite a number of plants which are claimed to improve indoor air quality; however, existing scientific research does not confirm this and trials are ongoing. If you wish to experiment yourself, ‘recommended’ plants include: spider plant, mother-in-law’s tongue/snake plant, money plant, rubber plant and other members of the ficus family, peace lilies, ivy, philodendron, aloe vera and dracaena. Improving indoor air quality is more successfully achieved by stopping all use of chemical cleaning agents, by replacing synthetic furnishing fabrics with natural ones, by disposing of any scented candles as these are known to give off more toxins than cigarette smoke, and by switching off and completely disconnecting all electronics when not in use.

Q. I am constructing a house in Karachi in Defence Housing Authority and have two mature lignum trees in the area where the boundary wall is to be constructed. While the trees themselves do not come in the way of the wall, the contractor tells me that digging for the foundation of the wall will require chopping off of a major portion of the roots. Is there any way of saving these trees?

A. Lignum vitae (guaiacum officinale) trees are very attractive and losing mature ones is a painful prospect but, depending on their size, this is what will happen unless you can have them professionally moved before construction work begins, using specialised heavy machinery, with most of their roots intact and immediately planted elsewhere.

All your gardening queries answered here

Q. Can spent tea leaves, from the teapot, be used as fertiliser?

A. Rich in nutrients and some trace minerals, used tea leaves can be rebrewed and the liquid used to give your plants a general boost, or they can be applied directly on to the soil around plants, such as tomatoes and roses, which enjoy slightly acidic soil conditions. They are also a good ingredient for compost heaps/bins.

Q. I have a tiny kiyari next to the main gate and around five spare pots for plants and want to grow plants that will attract bees. Can you suggest some suitable varieties and also recommend a place to purchase these plants and seeds in Islamabad.

A. Please take a look at this column in the issue dated October 13, 2019 (it can easily be found on the internet), where details of many bee attracting plants are provided. Additionally, as you are in Islamabad, a visit to the Honey Bee Research Centre in Chak Shahzad may also prove highly beneficial as they run trials involving honey bees and native plants. There are quite a few plant nurseries for you to browse through in Chak Shahzad, too.

Q. Two months ago I bought a very costly pink and white, imported, about three feet tall, Bougainvillea, but the flowers and leaves died and dropped off within days. The inside of the stems is still semi-green. How should I care for it and help it grow again?

A. Bougainvillea thrives on neglect. They need well-drained soil, plenty of sun, very little water and no feeding whatsoever. If your plant isn’t yet showing signs of new life simply ensure that drainage is good, that it’s in a sunny spot and then let it be. Hopefully your patience will be rewarded.

Q. I planted a banana tree in my Karachi garden two years ago. It receives four to six hours of direct sunlight daily and is watered every other day but has not flowered or fruited yet. The plant is healthy and produces new leaves at a fast rate.

A. Banana plants grow rapidly and equally rapidly deplete the soil, they are planted in, of essential nutrients and minerals. In the two years since you put it in, the banana plant will have totally drained the soil of food and the result is a hungry plant. While it is still producing healthy new growth, it probably does not have enough energy to develop flowering stems and fruit. I suggest that you feed it and feed it heavily, by spreading a four-inch layer of old, well-rotted, preferably organic, manure all over and around the area on top of its roots without — this is important — allowing the manure to come in to direct contact with the plant stems. If you cannot find suitable manure, use homemade or purchased organic compost instead or, if the banana plant is surrounded by so many other plants that mulching is difficult, feed it with a well-balanced, liquid fertiliser — organic, please — mixed with water, as per the directions on the packet, which vary from brand to brand. Mulch/compost will be pulled down into the soil, to feed the plant roots, by the combined actions of beneficial insects and watering.

Whichever method of feeding your banana plant you chose, do it once a month on a year-round basis and the result should be all that you can wish for.

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 8th, 2019