Agapanthus (agapanthus orientalis/praecox) are a feature of many gardens and public spaces here in New Zealand. With their ability to grow in many conditions, provide ground cover, and stabilise banks with their roots many gardeners love the plant. But they're not everyone's cup of tea; some people loathe them. Listener Helena isn't a fan and wants to know the best way to get rid of them. Bec Stanley, the curator of Auckland Botanic Gardens, has a plan and she also talks about her work developing new low seed and sterile varieties of agapanthus to appeal to the home gardener and eliminate the more invasive agapanthus orientalis from our gardens.

In 2013 Gaia, the world's most powerful space telescope, was launched by the European Space Agency. Its aim is to create the first ever HD map of our galaxy, the Milky Way, in order to answer those simple questions like where we come from, and what and where is dark matter (which apparently isn't even dark). The public's just got its first glimpse of the data collected by Gaia after 1000 days in space. Professor Gerry Gilmore is a New Zealander who is the UK's principal investigator for the Gaia project, and Professor of Experimental Philosophy in the Institute of Astronomy at Cambridge University.

Bin tracking, how GPS is changing our world, a 'digital hell', turbulence on planes and wearables and weight loss: do they work?

Christchurch is starting to track its half a million rubbish bins. The council is fitting all of its wheelie bins with Radio Frequency Identification (RFID) tags.Tim Joyce of Christchurch City Council shows us how the system works.

Greg Milner has written a history of GPS - the global positioning system developed in the '70s and controlled by the US military. He recently published Pinpoint: How GPS is changing our world.

Professor John Jakicic of the University of Pittsburgh led a US study that studied nearly 500 people; half used fitness trackers and half didn't. And it was the group without the tech who had lost more weight after 2 years! So what should we make of the research?

Kashmir Hill of fusion.net uncovered a digital horror story that revolves around location, and how the specific GPS coordinates of Joyce Taylor's Kansas farmhouse got linked to more than half a billion digital devices.

The rate of serious mid-air turbulence is increasing. Paul Williams from The University of Reading studies the air patterns that cause turbulence, and reckons that climate change is a big contributor to the problem.

With warmer weather not too far away (in theory), George Block of consumer.org.nz reviews the best line trimmers on the market. So should you go petrol or electric?

Sitting by a cosy fire, the smell of home baking, perhaps a few candles, and your nearest and dearest around you...the Danish would call all this 'hygge' (pronounced 'hoogah'). If you haven't heard of "hygge' yet you soon will, with a whole stack of books on the subject expected on the market in time for Christmas. Jeppe Trolle Linnet has become the go-to authority on all matters hygge since he publishished an academic paper on the subject back in 2011.