Diseases of roses and symptoms to recognize them. How to cure rust, white sore, scab, parasites and many other diseases that can affect our roses.
Phytosanitary interventions and advice on how to treat diseases of roses. From prevention to treatment with specific products.
Thediseases of rosesthey take root especially when the rose bush is weak and not vigorous enough to cope with the disease. Before we talk about specific cases, here is a series of pointers for prevent rose diseases.
Roses and irrigations, how much water to give
Unfortunately, not everyone knows that often irrigating the roses, but giving little water, does nothing but promote a bad development of the roots. Optimal irrigation allows the water to penetrate deep into the soil so as to allow the system to root a better development.
To better irrigate your roses, give at least 10 liters of water for each shrub. Irrigation should be performed only once a week in hot periods and can be done every other week in rainy periods.
When watering, be careful not to get the leaves and flowers wet.
Air the rose to prevent disease
Pruning roses is essential but it is not the only tool for airing your roses.
Once a week you have to aerate the soil by performing a more or less superficial scraping. You must prevent the formation of the surface crust and by aerating the soil you will allow the water to penetrate more easily, allowing for better root development. Roots placed deeper are synonymous with a strong and vigorous shrub.
TOtrust and the leafhopper of the rose
With rising temperatures, it is not uncommon to see your rose bush under siege, the culprits being the rose aphids (Macrosiphum rosae) or the leafhopper (Edwardsiana rosae).
These parasites are very common in the spring / summer. Fortunately, the treatment is common. Carry out a phytosanitary intervention with pyrethrum-4 (organic insecticide) or with azadirachtin-1 (also allowed in organic farming). Follow the dosage indicated on the purchase package. For those who prefer a treatmentbiologicalisnatural, better to intervene with the pyrethrum.
There are several pyrethrum-based insecticides on the market, they can be purchased in the form of powder, spray or concentrated liquid solution, to be diluted with water before use. L'natural insecticide pyrethrum-based can be purchased at specialized garden centers or can be purchased online: a package of Solabiol Piretro Actigreen Bio is offered on Amazon at a price of € 15.25 with free shipping. For all the info, I refer you to the official Amazon product page: Actigreen Bio Liquid solution.
Unfortunately, many people are convinced that pyrethrum is not effective but it all depends on the method of use. Pyrethrin is a photosensitive substance (it deactivates in direct sunlight), therefore, especially in liquid form, pyrethrum-based insecticides should be used in the late afternoon.
Where to distribute it?
On the whole surface affected by the parasites of the rose.
Diseases of roses: the white sore, symptoms and treatment
Sickness, better defined as Sphaerotheca pannosa fungal infection, can be counteracted with wettable sulfur-based interventions, also in this case we advise you to stick to the doses prescribed on the label. There are many sulfur-based fungicides on Amazon and in garden centers. Just dilute the liquid or powder in water and sprinkle the plant as prescribed by the manufacturer.
Diseases of roses: downy mildew, symptoms and treatment
Downy mildew infections (Peronospora sparsa) require multiple treatments. Downy mildew is recognized by the presence of faded spots on the leaves, with slight whitish mold and subsequent browning of the fabrics.
The treatment of downy mildew of the rose should be performed with tribasic copper sulphate or with a Bordeaux mixture. In both cases it is a product allowed in organic farming. Once again, we recommend that you stick to the doses indicated on the purchase package.
Usually, the treatment of downy mildew involves weekly interventions until the symptoms disappear.
Roses with holes in leaves, what to do
If yoursrosepresentsleavesdo not worry, this is a very common problem. Has there been a storm or strong wind lately? Generally it is the atmospheric agents that can pierce the leaves.
Another possibility, if you notice holes in the leaves, is linked to the presence of phytophagous insects, that is, insects thatgrazefeeding on the leaves of roses. Are you thinking about slugs? Usually slugs and snails do not target the leaves of roses, they prefer more tender leaves. Among the potential managers ofleaves of roses with holesthere is therose leafhopperto be fought with the pyrethrum as explained above.
How to care for roses
Other useful information is available in the guide article onhow to get rid of rose pests.