Fertilising clematis

Vigorously growing clematis should be fertilised in spring, when the shoots begin to appear. Late-flowering and long-flowering clematis as well as repeat-flowering, large-flowered hybrids benefit from a second dose of fertiliser in June. This gives the plant enough strength to impress with its large, colourful blooms a second time. Alternatively, further nitrogen can be stored at the time of spring fertilising with horn shavings, which then becomes available to the plants somewhat later. This combination comes very close to a slow-release fertiliser.

For clematis we recommend a good organic fertiliser which, besides supplying nutrients, also improves the soil in the long term. Mineral artificial fertiliser does act faster, but the feeding takes place directly and permanently harms the soil life – which should actually be responsible for it. With a mineral fertiliser it can also happen that you over-fertilise the clematis, and use over several years can salinate the soil in the long term. In poor soil, soil activator can also be used in autumn and spring. If for practical reasons only a liquid fertiliser comes into question, please choose an organic fertiliser concentrate here too, which can be given dissolved in water. 

Tip: when choosing the composition of your clematis fertiliser, look out for a natural source of phosphate. Added (soft-earthy) rock phosphate in fertiliser is not only nonsense but also highly questionable ecologically. This finite raw material, often mined in North Africa under questionable conditions, is hardly available to plants any more from a pH value of 6.8 and, moreover, is not infrequently contaminated with cadmium and uranium. (feel free to read more on this: Phosphorus fertiliser for organic vegetable growing: recycling instead of mining )

In particular, prettily packaged BIO products advertised as especially sustainable turn out on closer inspection to be not only expensive but anything but sustainable false packaging.

As the name 'woodland vine' already says, clematis prefer a woodland-like soil structure. Besides good drainage, this concerns above all the pH value, which should be in the slightly acidic range between 5.5 and 6.5. 

Above all the early-flowering wild species from the Alpina/Atragene group and Clematis Montana are therefore grateful for regulation with seaweed lime or rock dust. The pH value should not be too high, however, for the Italian and Texas clematis, which fits well with the fact that these are very happy to be combined with roses. 

For a clematis planted in a container the supply of nutrients should be ensured above all during the growing and flowering season. For one thing, fertiliser should be applied in advance; with organic fertiliser the dose can be given as early as autumn for the shoots in spring. Faster-acting mineral fertiliser is applied in late spring before the start of the growing phase. You should observe the dosage instructions, as it is easy to over-fertilise – just one of the reasons why we recommend organic fertilising.

Besides direct fertilising, soil improvers can also be added in a container, just as in the garden. The soil activator promotes soil life – and with it the natural formation of nutrients. These important natural nutrients are absorbed and processed by plants much better than those supplied via mineral artificial fertiliser – and incidentally also increase the water-holding capacity of the soil.