I'd like my windowboxes to screen pollution from the road in front of my house. Are there plants that are good for this?

Bushy ones are best, says Guy Barter, the head of horticultural advice at the Royal Horticultural Society, since it's what goes on in the soil that matters. “Choosing plants with dense foliage should mean lots of root activity and micro-organisms living in the soil, which help to combat pollutants.” But don't expect gleaming lungs if you live below a flyover. “There is some evidence to suggest that plants remove a bit of pollution, but certainly not all, and there is even less research into which ones do the job best,” says Barter.

If he were planting a windowbox near a main road, he'd plump for helichrysum - curry plant - with its mass of sprawling foliage.

Don't let pollution worries stop you from growing herbs or even tumbling tomato plants (www.suttons.co.uk/ tomato; pack of three plants £8.95). A thorough rinse will wash off any nasties.

In Japan trials have taken place involving planting sunflowers along roadsides, so you could always plant a few of the monster yellow flowers yourself. Gardening Express sells giant sunflower seeds, but look out, they could grow to 3m (10ft) tall (www.gardening express.co.uk; £1.99). However, don't end up with windowboxes that need heavy watering. Bushy plants can be greedy for water, so you might solve one eco-problem but create another.

Can you recommend a water bottle so I don't end up buying plastic bottles of water?

When it's hot it's hard to resist those handy-sized bottles of mineral water displayed in chill cabinets. Unless, of course, you can proudly whip out a refreshing alternative from your bag. My favourite water bottle is the lightweight Platypus water carrier. It comes in sizes from half a litre to six litres - the larger ones are good for camping - and folds up when it's empty, taking up less room than a plastic bottle, while containing more water (www.tentastic.co.uk from £6.50).

Another alternative is from Lakeland. I'm not usually one to recommend this online catalogue, but I was won over by its brightly coloured Cool & Go Drinks bottles. Each one features a built-in ice capsule, which you freeze overnight to keep your drink cool all day (www.lakeland.co.uk £4.99).

Good for gimmick lovers, but I'm happy with my own method of warding off thirst. I keep a bag of empty mineral water bottles in the kitchen and try to remember to rinse and fill one up every time I leave home. If I forget and end up buying one, I don't sweat it, as it will be reused several times before it goes into my recycling bin.

Times recommends

• Prince Philip attacks big families
• Take a dip in Dubai-on-Thames
• Eco Worrier: How can I persuade my husband to use a push mower?