Q Should I scrap my old car and get a greener model?

A Keeping an old banger on the road may seem like the right thing to do. You are, after all, advocating a “make do and mend” culture, which is, generally speaking, a praiseworthy approach to your belongings. But old cars are notoriously bad for the planet. I’m not talking about middle-aged models from the past few years, rather the exhaust-belching relics, manufactured when electric windows and cup holders were more important than low CO2 emissions.

“A 1970s Fiesta has an environmental footprint 70 times heavier than a new one,” Chas Hallett, the editor of Autocar, says.

“Investing in a fuel-efficient modern vehicle is the way to go.” David Kennington, at the Energy Saving Trust, agrees: “The average life of a car in the UK is about 13 years. Unless you do a low mileage each year, running a car that is older than this is inadvisable.”

What about the manufacturing costs and waste implications? Hallett points to recent research by Honda showing that manufacturing accounts for only 10 per cent of the total energy used by cars in their lifetime. The majority, roughly 85 per cent, is clocked up on the roads. Dumping your sub-standard wheels is the tricky bit. Sell it to someone else and you are handing the problem to another driver, which makes the scrapyard solution appealing, and with really old cars, possibly greener. A scrapyard, officially known as an authorised treatment facility (ATF), recycles the useful components, including metals such as aluminium and copper (some of which will go into the production of future cars). To find your nearest ATF, go to www.recycleyourcar.co.uk .

When choosing a new car, find a low-carbon model on www.dft.gov.uk/ActOnCO2 and whatgreencar.com , both of which provide independent environmental ratings.

Q Will setting my washing machine to 30C kill germs in clothes?

A Without getting too personal, it depends how germ-ridden you are. Normal clothes, including underwear, will come out clean as a whistle and perfectly hygienic, according to Dr John Bailey, a scientist at Procter & Gamble, who worked on this summer’s Ariel campaign to encourage us to wash our clothes at 30C.

The reason for this is the advance of washing machine technologies in the past decade. Not only do they enable us to wash our clothes at lower temperatures, but we can save up to 40 per cent of the energy required for each load. However, if you are dealing with what Dr Bailey calls “significantly bacterially contaminated” garments – ie, clothes from someone with something nasty such as diarrohea, he recommends soaking them in detergent before putting them in to the machine with the rest of your clothes.

The only other hitch in this worthy alteration to your domestic routine is that you might find unpleasant smelling gunk building up in your machine after a month or so, without a high-temperature wash to break it down. To combat this, the white goods company Miele suggests a high-temperature maintenance cycle (above 75C) at least every eight weeks. Although this may counter some of the good that you are doing by washing at 30C, but at least it will keep your appliance up and running.

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My garden looks a bit grim. The vegetables I tended over the summer months are exhausted; their fruits – beans, courgettes, aubergines and tomatoes – long gone, or in the deep freeze, and only their rotting stems fill my flowerbeds. A few lettuces and bitter strands of rocket and mizuna struggle on, but it’s not going to keep me going over winter. Being an amateur, I hadn’t thought this far. What now? Is there anything that grows under watery sun and icy blasts of wind?

For answers, I called on the expertise of my blog readers. Rocket, radishes and sprouting broccoli were recommended.

Sara suggested giving up on veg and sticking to herbs. “I nurture a load of oregano, mint, rosemary and thyme until spring,” she writes. Or there’s overwintering varieties of broad beans and peas that will be ready for an early harvest next spring. A greenhouse or polytunnel is the thing, according to Hedgewizard, whose blog – written from deepest Devon where he struggles toward self-sufficiency – is one of my favourites , hedgewizardsdiary.blogspot.com . “Under cover, winter salad will do OK; there are hints on the BBC gardening website ( bbc.co.uk/gardening ),” he says. Or, think to the future, says Ben. “Plant bulbs.”

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