What is the field telling you?

Rose Rust

What you see. Yellowish, then brown spots first appear on the underside of the leaf; brown patches follow on the upper side. In spring, orange-red aecia form on canes, leaves, bud stalks and sepals. Yellow urediniospores develop on leaf undersides through summer. Toward autumn, dark brown to black teliospores mature. If untreated, leaves drop.

What causes it. Fluctuating temperatures plus persistent leaf wetness. The fungus overwinters as teliospores on fallen leaves or as mycelium on young canes (viable for up to three years). Infection restarts in spring when basidiospores germinate on new shoots.

Why it costs you. Direct damage on bud stalks/sepals prevents 5–8% of buds from opening. The real loss is indirect: leaf spots impair photosynthesis, plant nutrition collapses, fewer flowers form, and rose oil quality drops with poor flower development.

Powdery Mildew

What you see. White, mealy mycelial coating on leaves, shoots and buds. Leaves curl, harden and channel; the whole leaf surface looks dusted with flour. Affected buds either fail to open or produce weak flowers. The white film blocks photosynthesis.

What causes it. Conidia and ascospores germinate optimally at 22 °C (range 5–35 °C). Hot, dry days followed by cool, humid nights are ideal conditions; under those, mildew can erupt epidemically within a week.

Black Spot

What you see. Brown to black spots on leaves, with characteristically irregular (not smooth) edges. As they enlarge to 1–1.5 cm, surrounding tissue yellows (chlorosis). Heavy infection causes early leaf drop. Replacement leaves the plant produces are weaker and even more vulnerable. Black spots also appear on stem thorns and on the bud's neck and sepals — hardening, preventing the bud from opening.

What causes it. Same conditions as rust — fluctuating temperature plus prolonged leaf wetness. The fungus enters first through tender young leaves and shoots. With a hand lens, small black fruiting bodies are visible at the centre of each spot.

Why it costs you. Whole-plant defoliation reduces stem strength, bud quality and bud size. Late-stage infection can kill buds outright before opening.

Rose Aphid

What you see. Body green or red-brown; males generally black. Both sexual and asexual reproduction. Through summer, asexual generations follow each other in rapid succession — ten to sixteen generations a year. The aphid pierces tissue with a long thin proboscis and drains plant sap. Found in colonies on shoots, buds and leaves; in heavy infestations, buds fail to develop normally.

When to act. Inspect before and after harvest. Treat when 20 of 100 sampled shoots show aphid colonies on the lower stem. Avoid excessive nitrogen fertilisation — it accelerates aphid populations. Stop all spraying 15 days before harvest. Never spray during harvest.

Two-Spotted Spider Mite

What you see. Greenish-yellow, pale yellow or reddish adults with a pair of dark spots near the centre of the body. Lives on leaf undersides; sucks sap, causing leaves to curl. Thrives in hot, dry conditions. Females begin laying in early March and weave protective webbing where they feed. Optimum development at 30–32 °C — 10 to 20 generations per year.

What it does. Sustained sap loss yellows and dries leaves, shortens plant height and reduces yield. In severe infestations, the entire leaf surface gets webbed over.

When to act. Visit fields frequently in June and July. Sample 100 representative leaves; treat when an average of 8–10 mites per leaf is found. No spraying during harvest.

Soft Scale

What you see. Hemispherical, 5–6 mm female adults; yellowish-brown with red striping. Overwinters as second-instar nymphs on canes and shoots. In spring, swelling adults turn from dark to lighter brown. Males pupate in late March; mating begins in early April. Egg-laying starts mid-May and continues for 1–1.5 months. Eggs hatch in early June, larvae fix themselves to canes and shoots.

What it does. Two damages in one. Sap-draining weakens the plant. Excreted honeydew supports sooty mould (fumagine), which blocks photosynthesis. Year one, plants stagnate. Year two, dwarfing, smaller leaves, fewer buds. Year three, dieback and chlorosis. Heavily infested rose stands can die out within 3–4 years.

Critical timing. Spray before the adult stage — late March to early April — with licensed product.

Rose Stem Sawfly

What you see. Adult is 20 mm long, glossy black, with smoky-yellow translucent wings and black wing veins. Overwinters as a mature larva inside a rose cane. Adults emerge in May and lay eggs inside one-year-old shoots. Egg is shiny straw-yellow and oval, with a brown projection at the end. Larva is ivory, 'S'-shaped, 20 mm long. Larvae bore through the pith of one-year canes and dry them out completely. One generation per year.

What it does. Tips of shoots that contain eggs droop downward and start to dry. Significant damage threshold: 5%. Decision to act is based on visual scouting in late spring.

The fundamental control. Because the larva lives inside the cane, chemical sprays are largely ineffective. Cultural control during winter pruning is the critical lever: identify hollowed-out, dried canes (the pith eaten through), cut at the affected section, and destroy the prunings.

Rose Curculio

What you see. Adult is 5–7 mm long, red-and-black, with a long curved snout (rostrum). Larva is ivory, plump, curled and legless. Adults appear on roses late April / early May. They drop to the soil to hide when threatened, active in sun. Females lay eggs inside opening buds; eggs hatch in 8–12 days, larvae feed inside. Mature larvae leave the bud and overwinter 2–8 cm deep in the soil in oval cocoons. Pupate in early spring. One generation per year.

What it does. During egg-laying the female partially severs the bud, which falls or hangs limply on the cane. Damaged buds rarely open; if they do, flowering is abnormal — yield drops directly.

May Beetle (Cockchafer)

What you see. Adults 2–3 cm, generally red-brown. The thorax is glossy black but covered in dense yellowish-grey hairs that mask the base colour. Eggs oval, cream, 2 mm. Larvae have curled, plump, white abdomens with three pairs of legs; the last segment is enlarged and dark from gut contents. Mature larvae reach 4–4.5 cm.

Source of infestation. Larvae arrive in the field via incompletely composted animal manure. The beetle attacks weak young plants and the roots of older roses. Root damage stresses the rose and lowers yield.

Rose Cutter Beetle

What you see. Long oval body, 1.5–2.5 cm. Head, thorax and elytra are brilliant metallic green. Larvae are creamy-white. Overwinters as adult or larva inside the root, with one generation every three to four years. Adults emerge from the root from late March; egg-laying runs from mid-May to late July; adults survive into late August. Larvae present year-round.

Tell-tale sign. Cut shoots and leaves found scattered under the rose canopy or hanging on the bush — the beetle's signature.

What it does. Sustained feeding weakens the rose and can ultimately kill it; severe infestations cause complete rose-stand removal and economic loss.

Beneficial Insects

The principle. Every chemical spray you apply kills the natural predators of the pest you are trying to control — along with the pest. The beneficials below already live in your field. Your job is to make them welcome and to spray as little as possible.

Reminder: chemical applications kill beneficials too. Use them as last resort and respect labelled doses.

Controlled Quality Composting

The principle. Composting has been practised for centuries, but in the Demeter system we use a scientifically improved ecological method called Controlled Quality Composting. The process delivers fully digested, top-grade humus within 6 to 8 weeks — highly effective in agriculture, 100% safe for the environment.

The conditions. Strictly aerobic. Windrows no wider than 3 m, no taller than 1.5 m. Constant moisture: 55–60%. An adequate compost turner must be used to maintain oxygen throughout.

What goes in (Aydın Gülyağı mix). Distilled rose petals (the high-energy starter), garden waste, farm soil, animal manure, and straw or hay/fodder.

What to watch for. CO₂ levels above 12% mean the heap needs turning to bring fresh oxygen in. Temperature must stay in the active range — too hot or too cold kills the bacteria. The protective outer skin (a thin layer of soil or straw) keeps UV, wind and rain from disrupting the inner heap.

How you know it's done. The mass becomes earth-like, crumbly, fragrant. The unpleasant smell of fresh manure has been transformed into the smell of forest soil.

Compost Tea

What it is. A water extract of mature compost, brewed with constant aeration to multiply the beneficial microbial population. Not a fertiliser in the classic sense — a biological inoculant. Sprayed on leaves, it crowds out pathogens. Watered onto soil, it kick-starts and feeds the rhizosphere microbiome.

How to brew. Place finished compost (about 1 kg) in a permeable cloth bag inside 20 litres of dechlorinated water. Aerate continuously with an aquarium-style pump for 24–36 hours. Add a small quantity of unsulphured molasses to feed the microbes. Use within 4 hours of brewing — microbial activity peaks fast and crashes faster.

When to apply. Early morning or late evening on overcast days; never in direct hot sun. Foliar application after pruning, before bud break, and again pre-flowering. Soil drenches at planting and twice during the season.

Why it works. Compost tea increases foliar microbial diversity, which physically and chemically excludes plant pathogens (powdery mildew, black spot). It also delivers soluble nutrients in plant-available form. Particularly effective in conjunction with biodynamic preparations.

BD500 — Cow Horn Manure

The raw materials. Fresh, well-formed cow dung from lactating cows that graze outdoors on pasture, or are fed clover-grass mixed with hay and straw. Any straw or plant parts must be removed from the dung. Only undamaged, well-formed cow horns may be used.

The making. Horns are filled with dung from late September to the end of October — by hand or with a spoon, packed all the way to the tip. They are buried immediately in a prepared pit and remain in the ground for six months until April.

Reading the result. Finished horn manure is dark brown, of homogeneous consistency, with the pleasant smell of humus or forest soil. Yield: roughly 60–150 g per horn depending on horn size.

Storage. Biodynamic preparations are living substances. Poor storage destroys quality; properly stored, they last for years and improve with age. Keep dark, cool, in the original mineral container, surrounded by peat insulation.

Application. Soil-orientated. Stirred rhythmically in lukewarm water for one hour, then sprayed on the field in autumn or early spring. Quantity: a small amount (~100–300 g) is sufficient per hectare.

BD501 — Horn Silica

The raw material. Crystalline quartz (SiO₂), pure — the crystals must not contain other minerals. Horns used for silica preparation must either be new or used exclusively for this purpose.

The making. Large quartz pieces are crushed with a heavy hammer, then ground further in a solid iron mortar until fine. The horn is filled vertically (no air cavities) and buried from March–April for six months until September–October. After unearthing, the horn is cleaned externally and the silica preparation extracted.

Application. Diluted in water and stirred rhythmically for exactly one hour before spraying. Used several times per year during plant growth, in counterpoint to BD500 (which is soil-orientated, while 501 is light-orientated).

Quantity. 4 g in 25–50 L water per hectare.

What it does. Promotes photosynthesis, raw-material assimilation and overall plant resilience. The polarity to BD500: where horn manure works on the soil and the root, horn silica works on light, leaf and metabolic activity.

BD502 — Yarrow Preparation

The raw materials. Yarrow flowers (Achillea millefolium), and the bladder of a red deer stag (Cervus elaphus).

The making. Yarrow is filled into the stag bladder. Filled bladders hang in a sunny, open-air location for at least three months before burial. Because they dry out during this aerial phase, they must be dipped briefly in water immediately before burial to ensure the yarrow is well moistened. Buried alongside BD500 cow horn manure in late September–October. Unearthed at the end of March–April.

Compost preparation. Used in small quantities (1–2 g per cubic metre of compost). Added to the heap during building — inserted into deliberate cavities at intervals along the windrow.

What it does. Brings sulphur-potassium dynamism to the compost; supports the rhythm of formation processes through which raw materials become humus.

BD503 — Chamomile Preparation

The raw materials. Chamomile flowers (Matricaria chamomilla) and small intestine (jejunum) of a cow. Where fresh intestine is unavailable, dried intestine can be used — it must be emptied and rinsed with water before stuffing.

The making. Chamomile flowers are stuffed into 30–50 cm pieces of intestine, tied at one end before stuffing and at the other after. Buried at the same time as BD500 in late September–October. Like BD502, dipped in water before burial since the casings dry in the air. Unearthed in April.

Compost preparation. Inserted into the compost heap in small quantities; helps stabilise nitrogen and supports a calm, settled microbial environment.

What it does. Calcium-sulphur action; tempers excess decomposition heat in the heap, supports the formation of stable, gentle humus.

BD504 — Stinging Nettle

The raw material. Stinging nettle harvested in the morning, left to wilt in light partial shade until afternoon. Dried nettles, if used, must be moistened with lukewarm tea brewed from nettle leaves before burial.

The making. No animal organ is required. A simple ceramic pot or similar container is buried with the opening facing upwards, packed with wilted nettle. The nettle remains in the ground for a full twelve months. When unearthed, what remains of the nettle is very small, deep black, with stem fragments often still visible.

Use. The most-used preparation in compost work — worth producing in larger quantities. Stems can be broken into smaller pieces before storage.

What it does. Iron and nitrogen mediator. Helps regulate nitrogen flow through the heap and downstream into the field; sometimes called the “stabiliser” of the compost preparations.

BD505 — Oak Bark

The raw materials. Ground oak bark and the skull of a domestic animal (typically cow or bull). Skulls must be cleaned of flesh — placed briefly in compost (protected from animals) until soft tissue is gone — and the brain cavity flushed clean with water before filling.

The making. Filled in September–October and buried in a place where rainwater flows and plant material accumulates. We open a pit, line it with rose-distillation waste, then place the skulls inside. Unearthed in March–April. Skulls are thoroughly cleaned of mud and soil; the preparation is extracted with wire, long nails or small tools.

What it does. Calcium-rich, plant-immunity preparation. Protects against the kinds of fungal pressure that powdery mildew, black spot and rust represent. Built into compost; supports plant resilience downstream.

BD506 — Dandelion

The raw materials. Dandelion flowers and the peritoneum and mesentery of a cow. Coordination with a butcher in advance is important to obtain these organs cleanly.

The making. Buried at the same time as BD500 in late September–October; unearthed in March–April. Care must be taken when removing the soil from the preparation — the soil and the preparation must not mix.

Use. Compost preparation, applied in tiny quantities to the heap during construction.

What it does. Silica–potassium dynamic. Brings sensitivity to the compost — helping the heap respond to surrounding environmental conditions. Long-term effect: improves the plant's relationship with light and warmth in the field.

BD507 — Valerian

The raw material. Freshly pressed juice from valerian flowers. Unlike the others, no animal sheath is needed and no burial period — it is prepared as a fermented liquid concentrate, stored in dark glass.

Use. A few drops are diluted in water and stirred for 10–20 minutes, then sprayed over the finished compost windrow as the final layer of preparation work. Also used as a frost-protection foliar spray on tender plants in spring.

What it does. Phosphorus dynamic; brings warmth to the compost and the field. Considered the “warmth blanket” that completes the cycle of compost preparations 502–507. The whole compost preparation set works as an ensemble: each preparation alone is incomplete; together they support the full digestive process of the heap.

Purple or reddish leaves

What you see. Leaves — typically the older, lower ones first — develop a purple, reddish or bronze cast. The discolouration usually starts at leaf edges or the underside, then spreads. New growth may emerge with a reddish tinge that does not fade.

Most likely cause: phosphorus deficiency. When phosphorus is short, the plant can't move sugars out of the leaves. Sugars accumulate, anthocyanin pigments build up, and the leaf turns purple. Common in early spring (cold soil reduces phosphorus uptake even when soil tests show plenty), and in compacted or waterlogged soils.

Other suspects. Cold stress on young growth (transient — fades as weather warms); root damage from overwatering, voles or root-feeding larvae (look for wilting too); some fungal early-stage infection (look for accompanying spots).

Yellow leaves (chlorosis)

What you see. Leaves lose their deep green and turn pale, yellow, or yellow-with-green-veins. Where on the plant the yellowing starts is the diagnostic key.

Pattern → likely cause.

Field response. Compost top-dressing addresses nitrogen and magnesium together over 2–4 weeks. For iron in alkaline Isparta soils, foliar chelated iron spray is the fastest correction — avoid soil iron amendments alone, they get locked up. Compost tea sprays bring micronutrients in plant-available form.

Brown leaf edges (scorch)

What you see. A crisp, dry, brown band along the leaf edge — sometimes a thin line, sometimes 1–2 cm wide. The leaf interior may stay green. In severe cases, the entire leaf edge curls inward and the leaf eventually drops.

Most likely cause: water stress. Either too little (drought, root injury preventing uptake) or too much (root rot, soil compaction). The plant fails to push water out to the leaf margins, and the cells at the edge die first.

Second suspect: salt buildup. Frequent over-fertilisation, brackish irrigation water, or accumulated chemical residues. Check soil EC if symptoms persist on irrigated bushes that look otherwise healthy.

Third suspect: cold injury. Late frosts on young growth produce a similar marginal browning, but only on the new flush.

Curled or rolled leaves

What you see. Leaves curl downward (cupping), curl upward (rolling), or twist into distorted shapes. New leaves often more affected than old.

Most likely cause: aphid colony. Aphids feed on the underside of new growth. Their sap-drain causes the leaf to curl around the colony. Pull a curled leaf open and look for the colony underneath. (See entry: Rose Aphid.)

Second suspect: spider mites. Especially in hot, dry conditions; look for fine webbing on leaf undersides. (See entry: Two-Spotted Spider Mite.)

Third suspect: water stress. Mid-day cupping that resolves overnight — the plant is conserving water. Adjust irrigation timing rather than volume.

Fourth suspect: herbicide drift. If neighbouring fields have been sprayed with growth-regulator herbicides (2,4-D type), wind drift causes characteristic twisted, fern-like new growth. Distinctive enough to confirm visually.

Wilting despite watering

What you see. The plant droops in the heat of the day and does not recover overnight, even after irrigation. Leaves go limp from the top down or from one cane at a time.

Most likely cause: root rot. Counter-intuitively, overwatering is the most common reason a rose wilts. Saturated soil suffocates roots; the plant can no longer absorb water even when it's there. Look for a sour smell at the root crown, blackened roots when you dig.

Second suspect: vascular wilt fungus (Verticillium or Fusarium species). Wilting starts on a single cane while others stay healthy; cutting the cane open shows brown streaking inside the wood.

Third suspect: voles or root weevils chewing the root system from below. Probe the soil at the root crown to look for tunnels or larval damage.

Stunted new growth

What you see. New shoots emerge but stay short. Leaves are small, internodes (the gaps between leaves) are tight. The plant looks compressed compared with healthy neighbours, but is not dying.

Most likely cause: scale insect infestation. Year two of a soft scale (Koşnil) infestation produces exactly this pattern — dwarfing, smaller leaves, fewer buds. Inspect canes carefully for the brown bumps. (See entry: Soft Scale.)

Second suspect: root constraint. Compacted soil, hardpan, root competition from a tree, or a rose grafted onto a poor rootstock. Dig a small test hole at root depth.

Third suspect: chronic underfeeding. Years of drawing the same crop without compost replenishment exhausts soil. Look at neighbouring rows for the same pattern.

Fourth suspect: virus. Rose Mosaic Virus and others produce mottled, distorted, stunted growth. Removal is the only cure; never propagate from infected plants.

Holes or chewed edges

What you see. Round holes through the leaf, irregular bites along the edge, or — in severe cases — only the leaf veins remain (skeletonised). The pattern of the damage tells you the culprit.

Pattern → likely culprit.

Decision rule. Cosmetic damage on 5–10% of leaves does not justify intervention — chemical sprays kill more beneficials than the pest does damage. Act when defoliation reaches 25% or when buds are at risk.

Sticky leaves (honeydew)

What you see. Leaves and stems are tacky to touch. A black, soot-like coating develops on top of the stickiness over a few days. Ants march up and down the canes.

What it means. Honeydew is the sugar-rich excretion of sap-feeding insects — aphids, scale, or whitefly. The sticky residue is the undigested plant sugar passed through. The black coating is sooty mould (fumagine), a non-pathogenic fungus that grows on the honeydew. The ants are farming the sap-feeders for the sugar.

Where to look. Trace upward from the sticky leaves. Sap-feeders cluster on new shoots, leaf undersides, or canes (in the case of scale). The ant column will lead you straight to the colony.

Why it matters. Sooty mould blocks photosynthesis. Sustained sap loss weakens the plant. Untreated soft-scale infestations can kill rose stands within 3–4 years (see entry: Soft Scale).