Buddleia is considered a decidedly undemanding ornamental shrub that literally "grows like a weed." In fact, the plant has to be cut down regularly so that it develops numerous new shoots and thus flowers - and does not bare from below. Sometimes, however, the summer lilac does not really want to grow, which is always a clear sign that it does not really like the location, the soil and / or the care.
If the summer lilac does not grow, it may be too dark
Causes of low growth
If the summer lilac does not grow, there can be various reasons. It is important that you first search for the specific cause and do not take immediate action. Only when the reason has been found can it be eliminated - with the result that the shrub finally grows as desired.
Wrong location
One of the most common reasons for a lack of growth in buddleia is a location that is too dark. The shrub needs a lot of sun and warmth - if it is in partial shade or even in the shade, it will not feel comfortable and will not grow as desired. The reason for this is the lack of photosynthesis: the plant simply cannot convert enough light into sugar, which in turn is needed for growth.
nutrient deficiency
In general, a lack of nutrients can be another reason for the measly growth. Although the summer lilac prefers well-drained, sandy soil, it needs a regular supply of compost, horn shavings (€32.93) and possibly stable manure. At best, work this natural fertilizer carefully into the root disc twice a year - once when the plants sprout and once in early summer.
Too heavy soil / waterlogging
If the soil is too heavy and/or even too wet, it's not just growth that suffers. Put the buddleia in a more suitable substrate as soon as possible or improve the existing one by mixing in sand, grit (€46.95) and, if necessary, compost.
Buddleia froze in winter
Buddleja davidii, in particular, reliably sprout from its roots every year despite frozen shoots - as long as they have not been damaged by the frost themselves. For this reason, you should always cover the root disc with a light winter protection, for example with fir or spruce branches, and pack pot specimens frost-proof.
tips
Diseases such as mildew, which occurs more frequently in humid summers, can also have a negative impact on growth. In the example mentioned, only a strong pruning and treatment with a decoction of field horsetail often helps.