RHS 1L Ready to Use Bug & Mildew Control

Product Information

The fungicides sulphur (Fungus Clear Ultra 2, Mildew Clear for Edibles), tebuconazole (Provanto Fungus Fighter Concentrate), tebuconazole with trifloxystrobin (Provanto Fungus Fighter Plus, Toprose Fungus Control & Protect), and triticonazole (Fungus Clear Ultra) are approved for the control of powdery mildewson ornamental plants.Tebuconazole with trifloxystrobin also carries a recommendation for control of 'leaf spots' of ornamentals, and may have some activity against the fungal leaf spot diseases of laurels. Like all scale insects scurfy rose scale is a true bug that feeds on plant sap. As adults they are immobile and covered in a waxy ‘shell’. Male scales are flat, narrow greyish white scales, up to 1mm in length.Female scales are pear-shaped and up to 2.5mm long. Eggs are laid in July or early August and hatch in August to September. Discoloured spots on the upper leaf surface correspond to pustules containing dusty orange spores on the lower surface Prune shrubs to give an open structure (which will again improve air circulation and reduce humidity)

Powdery mildew: the biology of powdery mildewis discussed in the web profile devoted to this group of diseases. Chooseless susceptible cultivars if downy mildew becomes a persistent problem. It is mainly a problem withbroad-leaved cultivarssuch as Veronica‘Midsummer Beauty’ and x ‘Franciscana Variegata’ but also occasionally present in some of the smaller-leavedspecies and cultivars,e.g . V. albicans, V. ‘Frozen Flame’ , V. rakiensis, V . ‘Youngii’ (syn. ‘Carl Teschner’) . The best time for summer spraying is in July when the more vulnerable newly hatched scale nymphs are presentFungicides for gardeners (Adobe Acrobat pdf document outlining fungicides available to gardeners) Links

Avoid overhead watering as this increases humidity around the foliage, which makes the plants more prone to powdery and downy mildews There are no fungicides available to amateur gardeners with activity against downy mildewor grey mould. RHS Bug & Mildew Control is a pesticide free, ready to use spray that works by physical mode of action and contains a blend of surfactants which stop the pests from moving and being able to feed. Ideal for flowers, fruit, vegetables and ornamentals, the spray can be used both outside and undercover to control a wide range of garden pests, including Aphid, Whitefly, Red Spider Mite, Scale, Mealybug, and Psyllid. RHS Bug & Mildew Control provides plants with foliar nourishment to promote healthy growth and abundant fruit, vegetables and vibrant flowers. When used regularly powdery mildew can also be controlled as the formula washes the foliage to remove any active mildew spores. No harvest interval is required, meaning any produce grown can be eaten within hours after application. What’s more this product is safe to use around the whole family, including children, pets wildlifeand Bees. The majority of the growth of most powdery mildews is found on the plant surface. The fungus sends feeding structures into the surface cells, greatly reducing the vigour of the plant. Because of this surface growth, powdery mildews are even more influenced by the environment than other plant diseases. Choosing the right plant for the right place, along with some simple measures to adjust the environment can go a long way to minimising powdery mildew issues in gardens. Further information on the management of downy mildews, powdery mildews and grey mould can be found in the advice profiles on the links below:There are considerable differences in susceptibility between rosecultivars. However, any claimed resistance to the disease may not persist for the lifetime of the plant, or be effective in all localities. Chemical control Adult females of this species mature in September or October, they are 5-7mm long dark brown and convex, immobile and attached to host plants stems. The adult male is winged and pinkish, at only 1.5 mm longit is rarely seen. Males die after mating but the females overwinter and produce white waxy egg masses in May or June. The egg masses are usually only found on stems and the wax can be pulled out in long threads; these characteristics distinguish this species from other insects that produce white waxy coverings such as cushion scale, fluted scale, horse chestnut scale, woolly aphidand mealybug. Stemphyliumsp. causessmall, dark brown or purple spots on the leaves. The spots do not merge together, nor enlarge in size. The centre of the lesion can sometimesbecome pale in colour. The infected leaves shrivel prematurely and can either remain on the plant or drop off.

The best time for summer spraying is in June when the more vulnerable newly hatched scale nymphs are present Prolonged leaf wetness is not required for infection by p owdery mildew, but high humidity is, so providing good air circulation is still important. Avoid drought stress and the overuse of nitrogenous fertilisers. Chemical control The fungicide tebuconazole with trifloxystrobin (Provanto Fungus Fighter Plus, Toprose Fungus Control & Protect) has a recommendation for the control of leaf spots on ornamental plants. Additionally, the fungicides tebuconazole (Provanto Fungus Fighter Concentrate) and triticonazole (Fungus Clear Ultra) are labelled for the control of other diseases on ornamental plants, and could therefore be used legally on Veronica(at the owner’s risk) to try and control the leaf spotting.

The RHS believes that avoiding pests, diseases and weeds by good practice in cultivation methods, cultivarselection, garden hygiene and encouraging or introducing natural enemies, should be the first line of control. If chemical controls are used, they should be used only in a minimal and highly targeted manner. Non-chemical control Powdery mildew, rustand leaf spots:The fungicides tebuconazole (Provanto Fungus Fighter Concentrate), tebuconazole with trifloxystrobin (Provanto Fungus Fighter Plus, Toprose Fungus Control & Protect), and triticonazole (Fungus Clear Ultra)are approved for the control of powdery mildew and rust diseases on ornamental plants. They would probably also give some control of rhododendron leaf spots (Provanto Fungus Fighter Plus and Toprose Fungus Control and Protect mention'leaf spot of ornamentals' on the label). Yellowish patches occur on the upper surfaces of leaves, often limited by the veins, corresponding to whitish patches of 'mould'growth on the lower surfaces Where you cannot toleratehydrangea scale, manage them using the information above as your first course of action. Plant invigorators combine nutrients to stimulate plant growth with surfactants or fatty acids that have a physical mode of action (e.g. Ecofective Bug Control, RHS Bug and Mildew Control and SB Plant Invigorator). These are not considered organic

Always follow the instructions on the products. For edible plants, make sure the food plant is listed on the label and follow instructions on maximum number of applications, spray interval and harvest interval. Asexual spores (conidia) of the g rey mouldfungus are always present in the air. They require leaf wetness or very high humidity to germinate and infect. Damaged or senescent plant parts are a very common way in which the fungus gains entry to the plant. The disease has a huge host range, and is active over a wide temperature range.None of the products in the lists above are likely to have any activity against bacterial shothole. Distorted leaves are often the first sign of infection, especially with the larger-leaved cultivars. A grey/mauve felt-like 'fungal' growth appears on the under-surface of the leaves, with diffuse purple-red or yellow patches developing on the corresponding upper surface. Badly affected shoots are best prunedout and disposed of as soon as the symptoms are seen. During routine spring pruning any shoots showing large patches of mildew around the thorns should also be cut out