In this article we’re looking at the seasons and asking when is the best time to create a green roof?
In theory, you can create a green roof at any time of year. However for your own safety and for the good of the plants we recommend greening your roof in either springtime or autumn. Summer is also a possibility – depending on the conditions.
Why we recommend creating a green roof in spring
- Great weather for working out of doors
- Avoid being on the roof in windy or wet conditions
- Plants establish quickly
- You see results within weeks of planting
- If using Enviromat or Meadowmat you should see lots of flowers in the first year
- Mother Nature helps with the watering-in
- Roof will be working well by summer and ready to help cool your building.
People seem to be at their most motivated and most energetic in the spring, and that’s always a good time to start a project. It’s a great time of year for establishing new plants and by and large, suppliers usually have plenty of stock at this time of year.
Over the winter, you will have been able to spot any problems with the waterproofing and you can get those fixed before the green roof buildup goes on.
Just be careful working at heights. Wet roofs are slippery and dangerous and you shouldn’t even think about being on top of a building in windy weather.
Watch the weather forecast before you order your live plants.
What are the challenges of creating a green roof in summer?
Summer time in the UK sees variable weather. Sometimes wet, sometimes hot and dry. A sedum green roof copes well with all weathers once it’s established. If you are laying sedum matting in summer, be absolutely that you will be able to water it daily for the next 2-4 weeks if necessary.
In very hot weather you will need to water at least twice a day.
Look after your own health too. Don’t allow yourself to get dehydrated or sunburnt. Remember that conditions on top of a building are often more extreme than at ground level.
- Your health and wellbeing – it gets very hot on a roof in summer
- Shorter shelf life for plants. Enviromat sedum matting MUST be unrolled as soon as possible after delivery. If not, the plants will die in the roll.
- Irrigating your green roof will need to be a priority for 2-4 weeks or until plants are well established
- You may miss the main flowering period in the first year
Why build a living roof in the autumn?
Autumn has a lot of advantages for planting in the UK. The weather is generally mild and moist. Great for plants and comfortable for you to work in too. More rainfall means you won’t need to spend as much time watering. But don’t get complacent. An Indian summer could take you by surprise!
Be wary too of autumn leaves falling onto your new plants and suffocating them. Be prepared to go up onto the roof at least twice during the autumn to check for and remove fallen leaves and to clear drainage outlets.
When you create your living green roof in autumn, the plants will build their root systems up during the winter months so you get a stronger floral display in spring. Just don’t forget the spring feed!
- Great time of year for establishing new plants
- Be sure to keep fallen leaves clear of your new green roof
- Expect a good show of flowers next spring and summer
Should you create a green roof in the winter time?
If you are using sedum matting to create your living green roof, there’s no reason why you can’t install in the winter.
- Be weather wise and stay safe when working at heights
- Do not try to install sedum matting or wildflower matting when it’s frozen
- Enviromat and Meadowmat are extra heavy when very wet. Make sure you can lift and manoeuvre it safely
How to build a living green roof using sedum matting
When is the best time to create a green roof?
The best time to create a living green roof is as soon as you are ready!
Remember to take appropriate precautions for your safety and please don’t work at heights during wet or windy weather. Enviromat sedum matting can be installed at any time of year and so can Meadowmat wildflower matting. But remember that both of these need to be kept moist for the first few weeks. That’s easier at some times of year than others.