Vegetation blankets – the ideal alternative to plugs and cuttings for green roofs

You are considering ordering or installing a green roof, but you’re uncertain whether to use vegetation blankets, plugs, or cuttings. Or perhaps you’ve been utilizing plugs or cuttings in the past for green roof installations and would like to learn more about the benefits of vegetation blankets. Well, you’ve come to the correct article. Here are all the advantages of vegetation blankets compared to plugs and cuttings listed for you.

Instant Green

By far the most compelling argument: vegetation blankets create instant green roofs as soon as they are rolled out. Green roofs planted with plug plants or cuttings take an average of 2 to 3 years to achieve the same result as vegetation blankets. It can even take longer in warm climates because the substrate can become very hot when exposed to the sun. Plants cannot grow over a hot substrate.

Less substrate

The substrate on green roofs with plug plants and cuttings must be 2-3 cm thicker than the height of the soil ball on the plug plants, which is approximately 6 cm. This means that a minimum substrate layer of 7-8 cm is required. Too much substrate can encourage weeds to grow on the already almost empty substrate and take over the roof. Green roofs made up of vegetation blankets do not require as much substrate and can’t be overrun by weeds.

Lightweight

Because green roofs with vegetation blankets require less substrate (approximately 2 inches), their weight is considerably lower. Green roofs with plug plants and cuttings are often 60% heavier than green roofs with vegetation blankets.

Installation all year round

Vegetation blankets can be installed all year round – even during winter months, except when it’s freezing. Cuttings can only be planted in spring and fall, if there are any cuttings available, and only in the right weather conditions, which is shifting due to climate change.

Lower maintenance costs

A roof is not a native environment for plants. It is drier, hotter, and there is more wind than on the ground. This means that it is more difficult to grow plants on roofs, especially from plugs and cuttings, because in their first year, the young plants need a lot of care and help growing up.

Because they are at least 95% pre-grown, the plants on the vegetation blankets are a year old and their roots already established. That is why they give you a quick and direct green result. This also means that, for a year or more, they’ve received quality care from the grower in the nursery. After installation, the blankets are low maintenance and hardly allow any weeds to grow. Roofs with plugs or cuttings, on the other hand, need a lot of maintenance.

For example, because their roots are shorter, plugs and cuttings require more water and fertilizer over a longer period than ready-to-lay vegetation blankets, which have an already fully established root system. In addition, they need to be checked regularly to make sure any dead plants are replaced and weeds are removed. The latter is a result of the fact that a big part of the roof doesn’t contain any plants after installation, so weeds have a lot of space to start growing on the empty substrate, stealing space from the plugs and cuttings.

Wind erosion

Vegetation blankets suffer very little wind erosion because the underlying substrate is covered entirely by the vegetation blankets. Initially, 95% of the substrate on roofs with plug plants or cuttings is exposed. The substrate is largely made up of a mixture of (lava) pebbles. Strong winds or storms can blow these pebbles off the roof, damaging the surroundings such as cars parked alongside the building.

Cooling Effect

A significant advantage of green roofs is their cooling effect during the summer. Unlike green roofs with plug plants or cuttings, green roofs with vegetation blankets allow you to enjoy this benefit immediately. For the most part, green roofs with plugs and cuttings initially consist of substrate. Uncovered substrate becomes very hot when exposed to the sun, negating the cooling effect of the plants.