My colleague Emma’s final way to give without spending money was to ‘be happy’. Well gardening makes me happy, but I like to think that there are great ways to garden and give at the same time.

One: Acquaint yourself with New Zealand’s invasive weeds and do something about them. Pest weeds are often beautiful - many a glowing orange montbretia, spectacular banana passion fruit or silvery ground-covering aluminium vine has been helped in its insidious spread across New Zealand by gardeners innocently taking it as a cutting or spare plants from a hedgerow or friend’s garden.  For an A to Z list of baddies see the Weed Busters list. Once you know which hostile aliens have invaded your garden, then set about eradicating them. It’s not easy but it can be done and the likes of Wandering Willie, old man’s beard, the ubiquitous agapanthus and many others will no longer be spreading from your patch to choke native growth.Two: Make your garden lizard-friendly. Attract lizards by mulching, planting berry or nectar producing plants, minimising use of sprays, planting dense groundcover and vines - such as native clematis - and provide hiding places such as old logs or untreated timber, piles of rocks or corrugated iron. You'll find more information here.

Three: When planting your garden, choose plants and shrubs that will provide food and habitat for native birds and butterflies. Mitre 10 provides a comprehensive lists of plants to attract fabulous flapping things. If you have a cat then fit it with a collar with bells, keep it in at night - prime cat hunting time - and place bird feeders, bird baths and nesting boxes at least 3m from bushes and areas where cats can hide.

Four: Where appropriate, plant up your road reserve. Some councils - such as Wellington City Council at set times of the year - will even provide suitable plants free of charge for this purpose. In the meantime, if you’re thinning out those native irises or wondering what to do with the native grasses seedlings popping up everywhere, then use them to beautify that dull grass verge instead.

Five: If you haven’t got a garden of your own then volunteer at your nearest wildlife sanctuary or reserve. You’ll find there’s plenty of demand for people to do green-fingered stuff from weed control to planting programmes.

(You can also read part one, part two and part three of Five ways to give without spending money).