Advice and care
Describe what you see on the plant, or choose a common symptom.
Rust
Reddish-brown (rusty) spore pustules on the underside of the leaves; the leaves gradually turn yellow and dry up.
Cause
Rusts (e.g. Puccinia asteris). Rust spreads by water, wind and infected seed.
What to do
- preventive: fungicide spray
- remove and burn affected plants
Bacterial diseases
Water-soaked or oily spots on the leaves, often with a yellow margin; the bacteria break down the tissues and cause rots. Spread by water (rain, irrigation), insects and people (infected seed, tools).
Cause
Bacteria that attack plant tissues.
What to do
- preventive: hygiene and phytosanitary measures, healthy propagation material, careful watering
- no bactericides are available in Czechia; copper-based products have only a limited effect
Aphids
Small sap-sucking insects on young growth and the underside of leaves; they cause distortion and discolouration. They excrete honeydew, on which sooty mould grows. An important vector of viral diseases.
Cause
Aphids (Aphidoidea). Excess nitrogen encourages outbreaks.
What to do
- direct: a strong jet of water or a soap solution, insecticide spray; in greenhouses, biological control (aphid midges, ladybirds)
- preventive: do not overfeed with nitrogen, check the underside of the leaves
Scorch, sunburn and drought
Dry brown leaf edges and tips, dried-out patches; typical of newly planted plants, full sun and wind, or lack of water.
Cause
Scorch and incorrect (insufficient) watering; for outdoor plants, wind as well.
What to do
- in the first year, water regularly and generously, and mulch
- shade sensitive species or plant taller neighbours beside them
- cut off damaged leaves
Leaf spot diseases (fungal)
Well-defined spots on the leaves, brown to black, often with a pale margin or a dark centre (in some, black dots of fruiting bodies are visible). The spots enlarge and merge, and the leaf dries up and falls early.
Cause
Fungi of the genera Septoria, Phyllosticta, Ascochyta, Colletotrichum, Coniothyrium and others. They spread in damp conditions.
What to do
- preventive: remove fallen leaves and affected parts, open up the planting, do not water onto the leaves
- direct: spray with a suitable fungicide
Rose black spot
From May, brownish to brown-black spots of various sizes on the leaves; the leaves then turn yellow and fall, and the plant gradually weakens.
Cause
A fungal disease (Diplocarpon rosae). Encouraged by damp conditions.
What to do
- preventive: more resistant varieties, remove and destroy affected leaves, improve air circulation
- direct: fungicides (e.g. Discus, Dithane DG Neotec, Sylit)
Rust (on ornamental plants)
Orange to brown spore pustules, most often on the underside of the leaves; there may be yellow spots on the upper side. A heavy attack distorts and dries out the leaves.
Cause
Rusts of the genera Puccinia, Phragmidium, Cumminsiella and others. The hosts are roses and many perennials. They spread by water and wind.
What to do
- preventive: remove and burn affected leaves, reduce humidity
- direct: fungicides
Tospoviruses (INSV, TSWV)
Necrotic rings and line patterns on the leaves, blackening, stunting and distortion of plants. Widespread on ornamental plants in greenhouses.
Cause
Tospoviruses: impatiens necrotic spot virus (INSV) and tomato spotted wilt virus (TSWV). They are transmitted by thrips.
What to do
- preventive: control thrips (the vectors), remove and destroy affected plants, check new plants
- viral diseases cannot be cured: prevention and removal of sources are the basis
Vine weevil / weevil (Otiorhynchus)
At night the adults eat characteristic curved notches in the leaf margins. The most dangerous, however, are the white larvae in the soil, which eat the roots and crown; the plant then wilts and dies (often begonias, primulas, rhododendrons and container-grown perennials).
Cause
Black vine weevil (Otiorhynchus sulcatus) and related species.
What to do
- direct: against the larvae, biological control with the parasitic nematode Heterorhabditis (watered into moist soil); against the adults, contact insecticides in the evening
- preventive: check the root balls of new plants
This is general information. When using plant protection products, follow the label.
Planting step by step
- Set out the pots by number
Do not plant anything yet. Set the pots out on the border exactly by the numbers in the planting plan, tall ones at the back (framework), low ones at the front (edge). - Check the spacing
Step back and look from above. There should be gaps between the plants. They will fill them once they have grown together. The recommended spacing is given for each plant (spacing in cm). - Photograph the layout
Before you start planting, photograph the border from above. If something does not fit, now is the time to move it, not after planting. - Plant in groups
Start with the framework (the tallest, at the back), then the filler, and finally the edge. Plant to the depth of the pot, firm in and water at the roots. - Water and mulch
After planting, water generously (~10 l/m²) and mulch the surface between the plants 5–7 cm deep. This holds moisture and suppresses weeds. - Note the planting date
Make a note of the planting day. We will use it to prepare a care plan for the first, most sensitive season.