Ornamental Plants

1. Identification and origin

Ornamental plants encompass a vast set of herbaceous, shrubby, arboreal, climbing and succulent species, cultivated for aesthetic, landscape or functional purposes. They include native and exotic species, from various biomes (tropical, Mediterranean, temperate, arid). They are used in gardens, parks, public spaces, interiors, nurseries and pot production.

2. Economic importance

The ornamental sector represents a relevant segment of horticulture and floriculture, with high economic value. It includes the production of potted plants, indoor plants, garden plants, ornamental trees, shrubs, climbers, lawns and cut plants. Demand is driven by landscape architecture, green urbanism, decoration and export. The diversity of species allows continuous production throughout the year.

3. Botanical description

Ornamental plants span multiple botanical families, displaying great morphological variability:

Annual and perennial herbaceous plants
Woody shrubs
Ornamental trees
Climbers and lianas
Succulents and cacti
Indoor plants adapted to low light

The ornamental characteristics include flowers, foliage, habit, texture, colour, fragrance and crown shape. The root systems vary widely, influencing the type of container, substrate and management.

4. Soil and climate requirements

The requirements vary according to the species, but there are general principles:

Well-drained substrates, with a stable structure and good water-retention capacity
pH generally between 5.5 and 7.0, depending on the group
Specific thermal requirements (tropical, subtropical, temperate)
Need for adequate light (full sun, partial shade, shade)
Variable sensitivity to cold, frost, wind and salinity
In pot production: light substrates, fertigation and rigorous control of humidity

5. Main pests

Whitefly (Bemisia tabaci, Trialeurodes vaporariorum): sap sucking and transmission of viruses
Thrips (Frankliniella occidentalis, Thrips tabaci): leaf lesions and floral damage
Aphids (Aphididae): leaf curling and transmission of viruses
Mites (Tetranychus urticae, Polyphagotarsonemus latus): chloroses and necroses
Scale insects (Diaspididae, Coccidae): sap sucking and sooty mould
Leaf miners (Liriomyza spp.): leaf galleries in herbaceous and foliage ornamentals
Nematodes (Meloidogyne spp.): root galls and vegetative decline

6. Main diseases

Damping-off and root rots (Fusarium spp., Pythium spp., Rhizoctonia solani): seedling death and root necroses
Powdery mildew (Erysiphe, Podosphaera, Oidium spp.): white spots and reduction of photosynthesis
Downy mildew (Peronospora, Plasmopara spp.): angular spots and necroses
Grey mould (Botrytis cinerea): rots on flowers and tender tissues
Anthracnose (Colletotrichum spp.): leaf and stem lesions
Rusts (Pucciniales): pustules and leaf drop
Cankers and woody rots (Botryosphaeria spp., Phytophthora spp.)
Various viruses (CMV, TSWV, ToBRFV): mosaics, deformations and loss of ornamental value

7. General crop management

The management of ornamental plants is based on cross-cutting principles:

Selection of species adapted to the climate and the planting site
Use of quality substrates and adequate drainage
Balanced fertilisation, avoiding excess nitrogen
Controlled irrigation, adjusted to the species and the container
Adequate ventilation in greenhouses to reduce humidity and fungal diseases
Regular monitoring of pests and diseases, with preventive measures
Formative and maintenance pruning to ensure aesthetics and health
Cultural hygiene: removal of infected leaves, flowers and plants
Crop rotation in nurseries to reduce the pressure of soil pathogens

Bibliographic references

EPPO Global Database – Ornamental plants (various species)
CABI – Crop Protection Compendium – Ornamentals
Pscheidt, J. W., et al. (2018). Diseases of ornamental plants. Horticultural Reviews.
FAO (2021). Ornamental Plant Production and Nursery Management.
Daughtrey, M. L., et al. (2014). Compendium of Flowering Plant Diseases. APS Press.
López‑Gálvez, G., et al. (2020). Greenhouse ornamental production. Acta Horticulturae.