That raspberry plants get yellow leaves is basically not a question but a statement. And it is relatively unimportant whether it is at a hobby gardener's home, during the production of pot/container plants, in our variety garden or even at our breeding facility. But as diverse as the individual raspberry varieties are, so versatile are the causes of the yellow leaves. And there is not always a serious disease behind it; it can also be a completely natural physiological effect. In the following, we have described the most common and most important symptoms in more detail for you and also show you the causes so that you can derive a recommendation for action.
Yellow leaves and their cause
By the way, did you know that plants are quite capable of compensating for up to 30% of their assimilation capacity? This means that plants can increase the assimilation capacity in the remaining leaf mass to such an extent that the energy produced in the total remains identical.
According to this, yellow leaves are by no means a death sentence for raspberry plants, but nevertheless a first indication that the plants do not feel 100% well.
As described at the beginning, you will find the most important symptoms and their causes in tabular form below.
|The oldest leaves get brown spots, become yellow and fall off||Natural leaf death -> even in the vegetation period the leaves can be rejected by the raspberry plant if they become unproductive|
|Complete canes from the last year hardly grow at all and have simultaneous flowering and fruit formation||Damage to the two-year-old canes -> due to mechanical or weather-related damage, fungal pathogens or animal pests, the wooden body is so affected that the supply of the leaves can no longer be guaranteed when there is simultaneous flowering and fruit formation|
|Fresh potted/planted raspberries form yellow leaves and show hardly any growth||Incorrect handling -> no insufficient tearing of the root ball; mulching of the plants|
|The entire plant is yellowish/light green, the oldest leaves are completely yellow, hardly any growth||Lack of nitrogen -> this is first and foremost apparent on the oldest leaves; mulch material can have a negative effect on the availability of nitrogen during decomposition|
|Young leaves have green leaf veins and yellow intercostal areas at the same time||Iron chlorosis/deficiency -> probably one of the most frequent causes of yellow leaves in raspberries (especially in the home garden); autumn raspberries are more affected than summer raspberries; pH values above 6.5 should be avoided because the roots cannot absorb iron from the soil|
|Yellowish white spots on the upper side of the leaves, usually in combination with a fine network of threads similar to spider webs||Spider mites/red spider -> can multiply explosively in a very short time; the network similar to spider webs is only formed during a mass infestation|
|Hanging and drying shoot tips; the plant dies from top to bottom||Root rot (Phytophthora) -> an infection with this fungus does not show itself first in the roots but in the death of the individual plants|
|Yellow spots on the leaves, sharply bordered by the leaf veins||Raspberry leaf mite -> probably the least common cause of yellow leaves on raspberries; an infestation is highly dependent on the variety; the summer raspberry 'Glen Ample' seems to be more susceptible to this than other varieties|
|Lemon yellow/lime green foliage on the entire plant||A varietal characteristic -> the low-growing raspberry variety 'Groovy' is characterised by this particularly striking foliage colouration|
Raspberries as ornamental plants
The raspberry variety BonBonBerry® Groovy (Jdeboer005(S)) has only been on the market for a short time and it is available as young plants at Lubera Edibles. With this raspberry variety, the yellow leaves are not a disease/deficiency symptom; the yellow leaves are simply a varietal characteristic. Also the leaves do not look diseased-yellow, as one might assume at first sight. The leaves of the raspberry 'Groovy' are characterised by a lemon yellow/lime green colouration, which can be easily recognised even from a distance. From late summer onwards, the dark red fruits provide an interesting and striking contrast to the yellow foliage. Raspberries as ornamental plants are a very special eye-catcher in every garden!