A green roof is known to be low maintenance, but that does not mean it is completely maintenance-free. To keep vegetation healthy, full and strong, periodic fertilization is important. The main question is: when is that necessary and how do you go about it the right way?

Why fertilize?

Sedum and other green roof plants grow in a relatively thin substrate layer. Unlike a garden, there is little natural supply of nutrients. Rain slowly washes minerals out of the system. Over time, this can lead to reduced growth, fewer blooms and bare spots in the vegetation.

Light, targeted fertilization helps keep the roof vital and well-sealed. This is not only nicer to look at, but also important for the protective effect of the green roof.

What is the right time?

The best time to fertilize a green roof is in spring, usually between March and May. At this stage, the growth period starts and the plants can absorb the nutrients optimally.

In most cases, one round of fertilization per year is sufficient. Only when the roof is visibly weakened or has been greatly washed out by prolonged rain, an additional light fertilization in the fall may be necessary.

What fertilizer are you using?

A specially formulated, slow-release fertilizer is used for green roofs. Ordinary garden fertilizer is often too rich and can actually cause problems, such as excessive growth or extra weeds.

Sedum grows naturally in poor soils. Therefore, over-fertilizing is more harmful than under-fertilizing. It’s all about balance.

What happens without fertilization?

When a green roof is not fed for years, the vegetation can thin out. This creates open areas where weeds settle more easily. Also, the protective effect of the roof decreases. So regular fertilization helps to extend the life of both the plants and the roofing.

Take maintenance completely out of your hands?

At Green Roof Specialist we offer professional maintenance for green roofs. During a maintenance service we check the roof, remove unwanted storage, inspect the drains and include fertilization as standard.

This way you can be sure that your green roof gets exactly what it needs, at the right time and with the right nutrition. The maintenance is taken out of your hands completely, so you can continue to enjoy a healthy and sustainable green roof without any worries.

Want to know what maintenance entails for your roof? We are happy to advise you appropriate to your situation.