How should you maintain a green roof? (2026)
Maintain a green roof at least twice a year. Remove weeds, clean drains and fertilize the roof with special sedum fertilizer. Water during prolonged drought and check regularly for bare spots or blockages. This will significantly extend the life of green roofs.
Maintaining green roof in 5 clear steps
1. Check roofing and edges
Inspect the green roof at least twice a year for open seams, damage or sagging. Also check the gravel edges and connections. Early detection prevents leakage and root damage.
2. Remove weeds and unwanted vegetation
Weeds can spread through birds and wind. Always remove unwanted plants root by root. This prevents competition for food and water.
3. Clean the storm drain
Clogged drains are one of the biggest risks with green roofs. Remove leaves, moss and debris so that rainwater can drain properly. Stagnant water can cause root rot.
4. Fertilize the green roof with special sedum fertilizer
Green roofs should be fertilized at least twice a year. Otherwise, the plants will not have enough nutrients to continue growing and the variety will decrease. Therefore, give them our eco fertilizer pellets in the months of March/April and September/October. With 1 kg you can fertilize per 20 m2 at a time. We recommend buying for a minimum of 2 spreading cycles with your order so you can get ahead for a while.
5. Water during prolonged drought and repair bare spots
Is the sedum turning red? Then it is in drought stress. Water the roof for 15-30 minutes until the understory is fully saturated. Sometimes bare spots develop on a green roof. This can happen from birds, weed removal or temporary drought damage. In many cases, the sedum will grow back closed on its own.
Want to speed up recovery? Then you can sow sedum cuttings on the bare spots.
What should you do immediately after construction?
In the first two weeks after planting, extra watering is essential. The sedum plants are not fully rooted at this time and are more susceptible to drying out.
During this period, check regularly to make sure the understory remains sufficiently moist. Especially in hot or windy weather, extra water may be needed to prevent failure.
When should you water a green roof?
After a dry period of several weeks, a green roof needs extra water. Often the sedum takes on a dark red tint during such a period, a sign that it is in survival mode. It is then advisable to water the roof thoroughly so that the underlayment also becomes well saturated.
How do you know if the underlayment is saturated? Once the roof drainage system allows water to pass through again, the underlayment is usually completely wet. This process can take about 15 to 30 minutes. Water the sedum up to twice a week and avoid watering in full sun. Keep doing this until enough rain has fallen or the roof returns to a fresh green or yellow color.
A drip hose can make maintaining a green roof easier.
Maintenance for a damaged green roof
You can recognize a damaged green roof by bare spots, moss formation or reduced growth. Possible causes include prolonged drought, shade, inadequate fertilization or a clogged drain.
- (If bare spots) Order sedum cuttings and fertilizer at sedum-fertilizer.co.uk.
- Remove any weeds from your green roof. Root and all.
- Clear your drain and make sure it can drain properly.
- Sprinkle cuttings over the bare spots.
- Fertilize the entire roof with sedum manure
- Is it not going to rain? Then water well again. Do not do this in full sun. This can cause the sedum to burn.
- Wait 3/4 weeks and the green roof will look much better!
- It may be necessary to do the maintenance again a few months later. Because the weeds were not removed well enough.
What should you do with a red green roof?
What should you do with a red green roof?
A red green roof usually means the sedum is in drought stress. This happens during prolonged heat or low precipitation.
Water the roof for 15 to 30 minutes until the understory is fully saturated. In most cases, the sedum will turn green again within a few days.
Red sedum is not directly harmful, but prolonged drought without water can cause failure.
Is your roof hard to reach? Then consider installing a drip hose. That way you can easily turn on the faucet when needed, without fussing with hoses or watering cans.
What are the maintenance costs of a green roof?
You keep the maintenance costs of a green roof low by doing timely maintenance. To fertilize a 20m² roof costs €24.95 every six months. Watering costs nothing if you purchase a rain barrel.
Fertilize: Use fertilizer specially designed for sedum, these have the optimal composition to make these plants grow as vigorously as possible. Also, there is lime in the manure which means moss has less chance.
Watering: During long periods of drought, water your plants. You can recognize this by the red color. Keep the cost of this as low as possible by purchasing a rain barrel and connecting it with a rain barrel pump and drip system.
Maintaining a green roof in the fall
Many people like to put off maintenance until spring, but it is actually essential to properly maintain your green roof in the fall. Autumn provides the perfect opportunity to prepare your roof for winter conditions so that your green roof remains healthy and functioning properly. Find out why a little attention now will prevent you from unexpected problems later!
Frequently Asked Questions
We assume that if two adults can stand on the roof, the roof is strong enough for our lightweight system, this system weighs only 45 kg/m2 saturated and is therefore suitable for almost all roofs around the house. However, this is not a guarantee. If you want to be sure, we recommend that you hire a structural engineer to check the roof.
A green roof has both ecological and economic benefits. Check out our page for this here.
After delivery, you can store the sedum mats rolled up for up to two days in cold weather. In warm weather, a maximum of one day. It is important to store sedum mats in a cool, dry place, directly out of the sun. You can also temporarily unroll and water the mats if you can’t handle them right away. For more information on caring for sedum mats, click here.
Installing a green roof is easier than you think! Using our instructional videos and additional tips, it won’t take more than a few hours! You can watch them here.
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