Extending the Growing Season: My Trials in the Keder Display Greenhouses

Over the past few months, Dianne and I from Growing Crazy have been spending a lot of time at Keder Greenhouses’ HQ, putting their display greenhouses through their paces and growing a wide range of crops across the seasons. Our goal has been simple: to see how these structures perform year-round and how effectively they can help extend the growing season, allowing us to keep harvesting fresh ingredients for as long as possible.

I’ve also been recording our progress through a vlog filmed on site, and this write-up shares some of the key observations from what we’ve seen so far.

Light Diffusion and Crop Performance

One of the first things I noticed was the impact of Keder’s diffused light panels on overall crop performance. Throughout the summer and into autumn, we harvested strong, healthy crops of tomatoes, cucumbers, peppers, and chillies.

The tomatoes in particular stood out to me because of how evenly they ripened. In my experience growing in traditional glasshouses and polytunnels, shadows and direct sun exposure often cause uneven colouring, but here the fruit matured consistently across the plants.

What really impressed me was that even towards late November, some of the late planted peppers in the raised beds were still ripening - a very encouraging sign of what this greenhouse environment can support.

Preparing the Structures for Winter

As the seasons changed, Dianne and I carried out a full clean-down of the greenhouses. This was done to maximise light levels during winter and keep everything as healthy and hygienic as possible for the crops.

Despite the grey, overcast conditions outside, the greenhouses stayed remarkably bright inside thanks to the light-scattering properties of the Keder panels. It’s made a noticeable difference as daylight hours shorten.

We’ve also been reorganising the lean-to greenhouse and are dedicating it entirely to herb production for the year ahead.

Winter Crop Trials

Across the different display greenhouses, we’ve now planted a range of winter-hardy crops to keep us producing food during the colder, darker months. These are all establishing well so far within the stable conditions provided by the Keder structures.

Winter Salad Leaves

• Mizuna

• Mustards

• Lettuce varieties

• Land cress

• Other winter greens

Stir-Fry Crops

• Pak choi

• Chinese leaves

• Purple sprouting broccoli

  
  

Herbs

• Mints

• Rosemary

• Lovage

• Thyme

• Sage

  
  

Other Crops

• Potatoes

• Succession plug plants being grown on to ensure continuity of supply

  
  

Looking Ahead

We’ll be back at Keder HQ in the new year to keep tracking how these winter crops develop. From there, we’ll start preparing for early-spring growing and laying out our bigger plans for the next summer season.

So far, these trials have been really encouraging. It’s been great to see just how much longer we can stretch the productive season inside the Keder Greenhouses  -  even as the weather outside turns cold and gloomy.

Growing Crazy for Pelargoniums

Alongside all of this work, the Growing Crazy team are also mega busy preparing for the long list of shows that we will be attending in 2026. On our website Pelargonium fans are able to preorder favourite and rare pelargoniums. We are also working on a range of additional products ...... all to be revealed very soon.

We also have some very exciting news coming up about Pelargoniums. Follow us on socials to be among the first to know.

Keder Greenhouse - The Ultimate Growing Environment

Get in touch with Keder Greenhouse today on 01386 49094 or email us at sales@kedergreenhouse.co.uk to find out more about our range of products.