Kew Gardens: A Year in Bloom

It's early spring in Kew Gardens and daffodils, crocuses and magnolia are bringing out the visitors in search of the first colour of the year. Also making a fresh start is Simon, the new head of living collections, and he's got the massive job of evaluating nearly 17,000 different plant species in the gardens to decide what stays and what goes. Meanwhile, Paul is doing a health check on the tuber of a dormant titan arum, a perennially popular plant that produces a huge flower that smells of rotting flesh. Kevin is also embracing change as he takes over as Kew's chief tree guardian, head of the arboretum. He's using sophisticated technology to see what is happening inside some sickly trees… that is, if the £5,000 computerised sonic hammer behaves itself. The 10-storey royal pagoda reopens for the spring season, and we get a guided tour with Rachel from Historic Royal Palaces. She tells us all about its history, from being a playground for Princess Augusta in the 1700s, through being used for testing bombs in World War II, to the cutting-edge restoration that has returned dragons to its rooftop and the whole structure to its former glory. Alberto shows us spring in the glasshouses, and we see the unusual emperor alcantarea go out in a blaze of glory. It grows two metres in two weeks and then produces strange spikey flowers for the first time in its 20-year life — but this is the last thing it does before dying. Meanwhile, at Kew's sister site Wakehurst, conservation supervisor Steven is keeping ancient skills alive: he's coppicing the trees and using the wood to create hedgerows. Leaping into the 21st century, Chris is making a withdrawal from Wakehurst's high-tech Millennium Seed Bank. He is thawing deepfrozen seeds for Alice in the nursery, who brings them back to life and takes the resulting coastal plants down to the Brighton seafront as part of a multimillion-pound effort to return lost plant life to the area.

Spring is in full flow in Kew Gardens, as a carpet of bluebells brings visitors into the woodland areas. But not all bluebells are equally welcome, and at Wakehurst, RBG Kew's wild botanic garden in Sussex, Iain is on a mission to hunt down the Spanish bluebell, which threatens our native species. It's a time for new beginnings, particularly for the lucky few on the prestigious diploma course. Like previous alumnus Alan Titchmarsh, these students could become tomorrow's horticultural megastars, such as Anna, who's creating intricate plant supports in the Woodland Garden, or Rob, who's working with endangered species in the Tropical Nursery. That's if they survive the traditional student clog and apron race! Out in the gardens, we see a pair of trees suffering from fatal storm damage and an aggressive fungus. Can Kevin find the perfect paired replacements for a vista that has UNESCO World Heritage status? We then go behind the scenes to meet Fran and Jenny, who use old skills and new tech to ensure there's a next generation of trees for Kevin to choose from. But the tree gang are foiled in their plans by a pair of ducks. It's an exciting time for Carlos in the Temperate House, as he nurtures a rare amaryllis that looks like it's going to flower for the first time after 10 years of care and attention. If it does, this will allow Carlos to pollinate it by hand, ensuring the survival of future generations. We go on the beat with Kew's very own constabulary, one of the smallest police services in the world, and reveal its 180-year history. We also dig into Kew's compost, with the arrival of tonnes of manure with a royal connection. Then, back at Wakehurst, we meet the Kew scientists using the latest drones and 3D modelling technology to help the government combat climate change with the power of plants.

Summer is rolling into Kew Gardens, and the giant waterlilies are once again drawing the crowds, who come to marvel at their size. This year, Carlos and Lucy think they've discovered a new third species of giant waterlily previously unknown to science. We follow them as they gather the evidence, along with partners in Bolivia, to try and prove their discovery to the world, and also see how Brie handles the monster-sized lily pads, when they take over the Waterlily House. Aaron is looking at ways to replace coffee plants threatened with extinction by climate change, pests and disease. With the future of our favourite beverage in his hands, we follow Aaron from the labs at Kew to the plantations of Uganda, and onto a coffee roaster in Bristol to find the perfect new brew. The stakes are high: if Aaron fails, it could mean no more coffee for any of us. We also find out from garden and plant historian Advolly how Kew had previously helped with a Victorian coffee crisis, and how Kew's first plant collector of colour played an integral part in the story. Down at Kew's wild botanic garden Wakehurst, Katie and the tree gang have to deal with some invasive rhododendrons that are threatening the plant collection, and it'll require abseiling with chainsaws to get to those hard-to-reach places. But not all rhododendrons are so unwelcome, and Olivia shows us their world-beating collection. We then learn about the Kew course that attempts to change the face of 21st-century horticulture and meet some of the inaugural students. In the Palm House, Florence overcomes her fear of heights to do some pruning in the roof and, back at ground level, Steph is refreshing the Alpine House plants ready for this year's summer rush.

The peonies are out in Kew Gardens, with staff and visitors enjoying their moment in the sunshine. But all is set to change, as Joe undertakes a massive year-long renovation of the peony garden. Meanwhile, the secrets of the peony are unveiled in Kew's Economic Botany Collection, where scientist Monique reveals the amazing healing properties of this underestimated shrub, and we find out about Kew's important work investigating the benefits, and dangers, of herbal medicine. It's also big change for Hélèna in the kitchen garden as all her precious vegetables are pulled up for a massive overhaul. Before she can get back and start replanting, Hélèna gets the unusual job of adding plants to some giantsized, mythical wooden trolls that have come to the gardens for an exhibition. In the glasshouses, Eleanor and Tom are playing with some deadly plants as they update the carnivorous plants section. We see Eleanor undertake some miniature landscaping and Tom introduces us to some scary plants with unusual carnivorous appetites. After the gardens close, we meet some of the people lucky enough to live onsite at Kew, such as head of tree collections Kevin, whose two boys have the best back garden any kids could have… even if Kevin does have to talk shop when he bumps into his boss Richard. In Sussex, at Wakehurst, Kew's wild botanic garden, Steven is keeping ancient traditions alive by making charcoal as part of his work managing the woodland. Meanwhile, Alice is working at the cutting edge, germinating seeds from the Millennium Seed Bank as part of Kew's mission to conserve all plant life in the world. We even meet a plant grown from a 200-year-old seed that was found in a wallet.

Dave tackles the massive dead-heading job that the roses bring to the gardens, while head of tree collections Kevin is contemplating another epic pruning job. It's all change in front of the Palm House, where, under a sweltering summer sun, the decorative team race to arrange thousands of new plants on the parterre, while Alberto is waiting on the flowering of the titan arum, which is always accompanied by the smell of rotten meat and an influx of curious visitors.

Winter leads to a carpet of snowdrops bringing in the visitors, and in the Rock Garden, Faye talks about the world of galanthophiles, the official name for snowdrop obsessives. In the warmth of Kew's glasshouses, Alberto prepares for his first orchid festival in charge, but luckily, he has help in veteran volunteer Henck. He and Alberto have set themselves the tricky task of creating a giant orchid sun in the middle of a pond.