As a child I loved the film Fern Gully. In one scene a character says: “All the magic of creation exists within a single tiny seed,” and that was the moment I became ‘switched on’ to seeds. Since then I have continued to grow, save and cherish them year-round.

Today, I think of seeds as invisible bees, essential to our wellbeing and survival but under siege from our modern lifestyles. First, there is a problem with seed biodiversity across the globe. This is down to the fact that we now grow and eat a small variety of grains, fruits and vegetables, mostly due to monocrop agricultural practices. It is no longer common to find hundreds of medicinal herbs growing in our hedgerows, or for bees to enjoy the nectar of endless species of flowers. Not only does the monocrop culture deplete the biodiversity that is around us, but it also puts other seeds out of the running.

It is with some relief, then, that I spoke to Indian-American activist Simran Sethi, named as a top 10 eco-hero of the planet by The Independent newspaper for her work. Simran is a champion in the food freedom arena, as she speaks for the heirloom varieties of grains and vegetables whose taste we have forgotten, while speaking out against the large corporations that seek to own these seeds and take away our freedom to grow them.

Simran argues that supermarkets choose to produce and sell only uniform, easy-to-grow varieties of fruits, vegetables and grains because it is easier to grow one crop at a time and to spray it with the same pesticides and the same amount of water. “Nowhere in Nature do we see growth like this, of a single variety of crop,” she tells me. In a natural woodland, the trees grow with the fungi and the flowers, the bees nest in the trees, and the leaves fall to create mulch and feed the insects on which other creatures feed. This is what a thriving ecosystem consists of. This is the essence of biodiversity.

When biodiversity is discussed, our thoughts do not often turn to seeds, but this is what Simran educates people about – the “precious older varieties of seeds [that] have fallen out of the food chain completely”. She talks about food heritage, about “the stories of individual seeds”. Seeds hold memories, and we can learn much from the missing seeds, the varieties that were pushed aside in order to propagate the ‘popular’ crop varieties that dominate supermarket shelves.

Simran says that this preference for uniform seeds is making them into “a non-renewable resource”, and this is why she calls seed monopolies the battleground of our time. So what can we do about it? Thankfully, a backlash against corporate control of seeds has begun, as Simran explains: “With more transparency over GM products, people can choose to boycott the patented seeds, and support farmers who favour seed diversity instead.” This shift of power from faceless corporation to individual grower is crucial to regaining the biodiversity of the seed kingdom. Simran says that this is starting to happen around the world, as “people are ... choosing to support farmers’ markets and local, chemical-free crops instead” as a way of avoiding GMOs. This support has also led to the resurgence of some heirloom plants, which dedicated small-scale farmers are putting time and energy into acquiring and growing, not for the love of profit alone, but for the love of labour and for the love of seed biodiversity.

Simran’s talk of seeds makes my mouth water. She tells me of a trip to the local farmers’ market, where she saw several varieties of aubergine, something that would startle many of us into looking twice. “We need these crops,” Simran tells me. “These are the seeds our taste buds crave”: the rare heirloom tomato like no other you have seen before, the strange squash that feels like nothing your mouth has ever felt. These textures, smells and tastes are missing from our palates, but we have also lost something else that they have to offer us: the “unique seed memories” that these seeds hold – and “we must remember that cultural changes come from diet changes.”

The good news, Simran tells me, is that “in recent years heirloom varieties of some crops have been gaining steady popularity, such as some tomatoes and types of onion.” Change begins with a single, simple step. All you need to do is contact an heirloom seed grower and ask for an unusual seed, then sow it in a pot of compost, home-made if possible. Tend to it, water it and watch it, and when it’s ready plant it out in the garden, in full or partial sunlight, as suggested by the seed donor. When it grows, leave the plant to seed, so that you can save those seeds for the following year, sow some and give some to those who wish to be part of the cycle. Now the seed has a new story, and when you pass it on, you do so along with the seed’s old story of where it was grown, where it has travelled, which cultures used to grow it.

It all begins with a single, tiny seed. And it ends with that too.

The first London Freedom Seed Bank Festival takes place on 11–12 October (p74):

Zion Lights writes for The Huffington Post and Green Living Ideas.