Step 1: Clean the green roof (twice a year)

A sedum roof catches leaves, twigs and other organic material. This can disrupt the growth of the sedum. A built-up layer of leaves prevents the plants from getting enough light and air. That’s why it’s important to clean your roof twice a year.

Both in spring (March–April) and in autumn (September–October), it’s best to remove leaves, branches and any dead plant debris. Use a leaf blower on a low setting or a soft brush to remove dirt without damaging the plants.

Tip: Do you notice bare patches during maintenance? No problem: you can easily fix this yourself by trimming back overly long plants and sprinkling these cuttings over the bare patches to fill them in again.

Colorful succulent ground cover above a strip of rocks

Step 1: Clean the green roof (twice a year)

A sedum roof catches leaves, twigs and other organic material. This can disrupt the growth of the sedum. A built-up layer of leaves prevents the plants from getting enough light and air. That’s why it’s important to clean your roof twice a year.

Both in spring (March–April) and in autumn (September–October), it’s best to remove leaves, branches and any dead plant debris. Use a leaf blower on a low setting or a soft brush to remove dirt without damaging the plants.

Tip: Do you notice bare patches during maintenance? No problem: you can easily fix this yourself by trimming back overly long plants and sprinkling these cuttings over the bare patches to fill them in again.

Step 2: Remove weeds and moss

Although sedum roofs are naturally low in weeds, unwanted plants or moss can sometimes grow, especially in the first years after installation.

  • Check the roof each season for weeds and remove them by hand (carefully pull them out with the roots).
  • Watch out for moss growth, especially in shady areas. A lot of moss often indicates a nutrient deficiency, so fertilising can help.

Tip: Avoid chemical pesticides; they can damage the sedum and  disrupt the ecosystem.

Yellow and pink groundcover flowers in front of a modern glass building

Step 2: Remove weeds and moss

Although sedum roofs are naturally low in weeds, unwanted plants or moss can sometimes grow, especially in the first years after installation.

  • Check the roof each season for weeds and remove them by hand (carefully pull them out with the roots).
  • Watch out for moss growth, especially in shady areas. A lot of moss often indicates a nutrient deficiency, so fertilising can help.

Tip: Avoid chemical pesticides; they can damage the sedum and  disrupt the ecosystem.

Step 3: Check the water drainage

A green roof buffers rainwater, but it is important that excess water can drain away properly. Therefore, regularly check that the drains or gutters are not clogged with dirt, leaves, or moss.

  • After a heavy rain shower, check whether the water drains away properly.
  • Clear the drains if you notice that puddles remain.

Tip: Good drainage prevents overloading the roof and protects the roof structure from moisture damage.

Stacked black seedling trays with young plants on a patio next to a wall

Step 3: Check the water drainage

A green roof buffers rainwater, but it is important that excess water can drain away properly. Therefore, regularly check that the drains or gutters are not clogged with dirt, leaves, or moss.

  • After a heavy rain shower, check whether the water drains away properly.
  • Clear the drains if you notice that puddles remain.

Tip: Good drainage prevents overloading the roof and protects the roof structure from moisture damage.

Step 4: Fertilize the sedum roof (1 to 2x per year)

Sedum plants are low-maintenance, but for healthy growth and strong roots they do occasionally need some extra nutrients. The substrate layer is relatively thin and contains few nutrients. During heavy rain, excess water is drained away, and the nutrients are washed away with it. Therefore, fertilise your green roof at least once a year, preferably in spring (March–April). Ideally, repeat this fertilisation in autumn (September) to ensure your green roof is prepared for extreme temperatures and stays nicely full.

  • Use a special sedum fertiliser with minerals such as potassium and phosphorus.
  • Spread the fertiliser evenly over the roof, preferably before or during a rain shower, so the nutrients are properly absorbed. If it stays dry for a long time after fertilising, it’s best to spray your roof lightly.

Tip: Fertilising helps sedum stay dense and strong, giving weeds and moss less chance to take hold.

Gravel terrace next to a brick wall, overlooking a lawn with a flat roof skylight and trees.

Step 4: Fertilize the sedum roof (1 to 2x per year)

Sedum plants are low-maintenance, but for healthy growth and strong roots they do occasionally need some extra nutrients. The substrate layer is relatively thin and contains few nutrients. During heavy rain, excess water is drained away, and the nutrients are washed away with it. Therefore, fertilise your green roof at least once a year, preferably in spring (March–April). Ideally, repeat this fertilisation in autumn (September) to ensure your green roof is prepared for extreme temperatures and stays nicely full.

  • Use a special sedum fertiliser with minerals such as potassium and phosphorus.
  • Spread the fertiliser evenly over the roof, preferably before or during a rain shower, so the nutrients are properly absorbed. If it stays dry for a long time after fertilising, it’s best to spray your roof lightly.

Tip: Fertilising helps sedum stay dense and strong, giving weeds and moss less chance to take hold.

Step 5: Provide water during extreme drought

Sedum roofs can cope well with drought, especially if the sedum mat is well rooted and fully grown. Normally, no extra watering is needed because sedum stores water in its leaves. However, during extreme heat and long periods without rain (4+ weeks) extra watering may be necessary.

  • Water in the morning or evening to minimise evaporation.
  • Use a watering can or garden hose with a spray nozzle for even watering.

Tip: Do you notice the sedum turning red or purple? That’s a sign of drought stress, so your plants could use some extra watering. Sedum will also turn red in autumn; that’s a normal process and does not indicate a water shortage.

Green grassy hilltop under a blue sky with scattered clouds

Step 5: Provide water during extreme drought

Sedum roofs can cope well with drought, especially if the sedum mat is well rooted and fully grown. Normally, no extra watering is needed because sedum stores water in its leaves. However, during extreme heat and long periods without rain (4+ weeks) extra watering may be necessary.

  • Water in the morning or evening to minimise evaporation.
  • Use a watering can or garden hose with a spray nozzle for even watering.

Tip: Do you notice the sedum turning red or purple? That’s a sign of drought stress, so your plants could use some extra watering. Sedum will also turn red in autumn; that’s a normal process and does not indicate a water shortage.