The rose as queen in the garden bed is not a humble plant, its demands on care are high. When everything is to her satisfaction, she supplies us with her most beautiful flowers in abundance. However, if something does not suit her, she reacts sensitively and shows us this clearly with yellow leaves. This fact cannot be ignored for long. The possible causes of this yellowing must first be identified and promptly rectified.
causes
When the beautiful green gradually disappears from the leaves of the rose, its beauty also disappears at the same time. Yes, even their lives may be in danger. No owner wants to accept this desolate sight, let alone lose their roses. But in order for her to be helped, her suffering must first be revealed. The following causes are possible:
- lack of nutrients
- iron deficiency
- spider mites
- Wrong mildew
- blackspot
garden rose
Go in search of clues
Yellow rose petals are clearly visible from afar and for everyone. However, the causes are not. A thorough study of the rose bush is required here. And of course the traces discovered must also be interpreted correctly. Knowledge of rose diseases and pests is necessary to make the "right diagnosis". Only then can tailor-made measures be taken.
nutrient deficiency
roses are heavy feederthat have high nutrient consumption. They need a mix of different nutrients in the optimal dosage. If there is a general lack of nutrients or certain substances are missing, the rose often reacts by yellowing its foliage. The following substances should be available in sufficient quantities for a rose bush during the growing season:
nitrogen
It is the fuel for growth par excellence. If it is absent, the leaves will turn pale and yellow. In addition, wild shoots can be observed.
phosphate
Among other things, low values result in yellow leaves or their shedding.
potassium
This nutrient is important for the hardiness of roses. A deficiency shows up as brown spots on the leaf blade.
magnesium
It is indispensable for the formation of leaf green. If this substance is missing, the leaves first become lighter, then yellow and finally brown.
calcium
It is an important pH regulator. If the rose lacks it, chlorosis (yellowing) often occurs.
sulfur
This substance is important for energy metabolism. When there is a shortage, young leaves turn light yellow.
tip: If you cannot clearly identify the deficient nutrient based on external signs, a soil analysis is helpful. As soon as you know what the rose is missing, you can supply it with the coveted substance.
Trace elements: iron and Co.
The rose requires large amounts of these main nutrients listed above. It also needs trace elements such as boron, chlorine, iron, copper and manganese. Iron deficiency in particular causes the rose petals to turn yellow. It is also this deficiency that causes the so-called chlorosis favored. This is also known as jaundice and bleach addiction. The formation of the green chlorophyll is disturbed due to a lack of supply or it is even broken down. In addition to the lack of iron, the following factors also promote the development of chlorosis:
- too calcareous soil
- heavy soil/substrate compaction
- persistent dryness or permanent wetness of the soil
Calcareous soils are not suitable for the cultivation of roses. These should definitely be improved with compost. The administration of commercially available iron supplements can also correct the deficiency in this nutrient.
tip: You can easily determine whether the soil of the rose is too calcareous by measuring the pH value. A value between 5.5 and 7 is ideal for these plants.
Spider mite infestation
A lack of nutrients weakens roses, making them vulnerable to pests and diseases. Spider mites, which are often up to mischief in dry and warm weather, can conquer weakened roses even faster. How to recognize a spider mite infestation:
- in the early stages they are not noticeable at all
- white, yellow or reddish dots can be seen on the leaves as the disease progresses
- these spots are getting bigger and spreading more and more
- small crawling animals can be seen on the underside of the leaves
- the webs of the spider mites are more conspicuous
Spider mites must be combated immediately, as they multiply extremely quickly and can also spread to other rose bushes or other types of plants. Spraying with soapy water has proven its worth. In the greenhouse or house, this pest plague can also be brought to an end with the help of predatory mites.
Spider mite infestation
Wrong mildew
A wrong location and/or too close a planting can promote downy mildew. On roses, this fungus appears with reddish to brown spots on the tops of the leaves and with a grey-white mold lawn on the undersides.
- Cut away affected areas
- dispose of in the residual waste
- never put it on the compost heap
- Treat rose with home remedies
- in the advanced stage, use a fungicide if necessary
blackspot
Blackspot is feared by rose owners because it is a very stubborn fungal disease that is difficult to combat. Most rose varieties are not resistant to it and therefore often fall victim to it. The rose petals do not simply turn yellow, but are colorfully patterned with a mixture of yellow, brown and reddish tones.
- Cut off affected shoots with a sharp knife
- Always disinfect garden tools
- Gather and discard leaves from the ground
- Diseased plant parts must not be composted
- Combat blackspot with a fungicide
- if the location is damp and shady, it is better to transplant roses
- a sunny and well-ventilated place is ideal
So that the infestation does not occur again in the following year, roses should be included as a preventive measure plant strengtheners be treated. Regular spraying with nettle manure or horsetail tea has proven effective. Also, avoid nitrogen-rich fertilization and when watering the roses, be careful not to wet their leaves with water.
Consider a combination of multiple causes
Yellow leaves don't have to be the result of a single cause. It is therefore important not to stop investigating the cause as soon as a possible cause has been found. Nutrient deficiencies and diseases often go hand in hand. Because if the vitality of the plant suffers due to a lack of nutrients, pathogens and pests have an easy time with the rose.
If you leave it at the first cause found and its elimination, this help for the roses may not be enough. The leaves remain yellow, new ones appear and the plant can even die.
So yellow leaves on roses don't give us time to calmly try out rescue measures one after the other until all the causes have finally been eliminated. Better take a close look from the start. Magnificent rose bushes have grown over years and shouldn't be wiped out in a matter of weeks or months.
Preventive care measures
At the latest after the causes of the first yellow leaves have been successfully combated, the question of the future of the rose arises: How can the green of the rose petals be effectively protected? Good care is the best means of prevention here:
- always provide sufficient planting distance
- avoid shady and damp locations
- Roses love it sunny and airy
- they should be able to dry well after rain
- ensure good soil conditions and continuously optimize them
- Loosen up the soil again and again
- analyze soil samples at regular intervals
- Keep the pH in the acidic range
watering and fertilizing
Always a challenge
Roses need a lot of water, which means you need to be careful when watering:
- pour carefully
- Do not wet plant parts above ground with water
- do not use a hose
- powerful jet of water washes away nutrients
- use watering can instead
- water regularly with small amounts in summer
- in autumn the water requirement decreases
The high demand for nutrients requires the use of a suitable fertilizer. The dosage must also be exact, because a poor supply is just as harmful for the roses as an oversupply.
- always fertilize as needed
- special rose fertilizer is ideal
- Observe the manufacturer's dosage information
- other natural long-term fertilizers can also be used
- Apply compost and horn shavings early and work in well
tip: Make sure to fertilize your roses on a cloudy day to avoid burning their leaves.
