Going To Seed

If you want a great plant, you need a great seed. And if you want a great seed, you need a great plant. So… who’s growing great plants?

Well, how about that Welsh guy? You know, the one from the island with the druids and all that. Medwyn Williams has been stacking national and regional vegetable competition wins for decades. He grows exceptional plants, and yes, you can buy seeds from him. And after seeing what he’s been up to this year, you’ll understand why his reputation is so well earned.

This summer, Medwyn gave us a behind-the-scenes look at his seed-growing operation, with a particular focus on onions. And his offerings for 2026 are shaping up to be something special. Join us as we take a closer look at his methods, timeline, and the equipment he uses to produce future champion vegetables.

The whole process starts with the previous year’s still-planted crop of Large Exhibition Onions, a unique re-selection developed by Medwyn himself. These massive, incredibly healthy alliums are overwintered in 1Pot XL modules. If Medwyn were overwintering onions in the ground, he’d likely need to dig them up, store them, and replant them in early spring. By using AutoPot, he avoids all that extra work, keeping the plants stable, healthy, and well fed inside his polytunnels.

If you’re tempted to turn up your nose at Medwyn’s seeds and produce your own, it’s worth noting that this method only works with certain types of onions. Avoid hybrids, as their seeds often fail to germinate properly or don’t come true to the parent plant.

By late spring 2025, Medwyn’s onions were producing some seriously trippy, ’90s-album-cover-style shapes in the form of inflorescences and rapidly developing flowers. This year’s weather played a huge role in encouraging thick, stalactite-like flower stems that could fully support the blooms. And while warm conditions helped vegetative growth, the heat and light did even more for pollination and seed production.

Onion flowers are self-pollinating, but they produce their best results when cross-pollinated. For that, bees are ideal, and by Medwyn’s account, they were out in force this year thanks to a warm spring and a long, hot summer. To boost pollination even further, Medwyn also hand-pollinated using a small brush. He recommends doing this early in the day, when pollen quality is at its peak. With that, the waiting game began.

Throughout their second summer of development, the plants were largely left to their own devices, automatically watered and fed by the XL modules. Like all AutoPot Watering Systems, the 6.6 gallon XL modules only supply water in response to plant uptake. That kind of responsiveness is especially useful during seed production, when plant needs can vary dramatically. The plants are large and the flowers need support, but the crop itself is technically finished, so it’s not a typical watering schedule.

Ten weeks later, anyone visiting the polytunnels might have wondered if the flowers had gotten up to something they shouldn’t have or had taken on some rather questionable shapes. In reality, nothing could have been further from the truth. Despite being covered with brown paper bags, the flower heads were developing beautifully, as Medwyn was about to reveal.

Once the bags were removed, each drying flower head was packed with an impressive haul of black seeds, ready for harvest. The paper bags were simply Medwyn’s way of preventing the seeds from falling to the ground once nature took over, a simple, elegant solution. Next step: trimming.

To extract the seeds, Medwyn cut the stalks below each head and discarded the larger pieces of dried plant material. The remaining stalks were then quietly relocated to his wife’s airing cupboard for additional drying. (If your onions ever smell like clean laundry, now you know why.) Jokes aside, this was an effective way to remove excess moisture before Medwyn gently rubbed the brittle stalks by hand to release the seeds, hopefully not in the airing cupboard itself.

For the final cleanup, Medwyn used a deep jug filled with water. Floating the seeds allowed the remaining flower debris to rise to the surface while the clean, viable seeds sank. A quick skim and sieve separated the two, and the seeds were then left to dry thoroughly, ready for sale.

Interested in trying some of these carefully prepared, pedigree-proven seeds yourself? We highly recommend heading over to Medwyn’s seed shop sooner rather than later. They tend to sell fast, and thanks in part to this year’s bumper seed crop, Medwyn has even lowered prices. Turns out there is still some love in the game.

For more insights into Medwyn’s methods and updates on new releases, follow him on X and Instagram.