< flowers and other herbaceous plants - Colorado State University Extension Tri River Area

Problems of Flowers and other Herbaceous Plants


Dr. Curtis E. Swift, Area Extension Agent (Horticulture)
Colorado State University Extension

  • The Black Vine Weevil Otiorhynchus sulcatus (Fabricus)
    This insect is seldom seen since the adult feeds at night, but it can cause considerable damage to flowers, shrubs and greenhouse plants. The adult notches the edges of leaves while the more damaging larvae feeds on the roots of the host plant.
  • The Geranium Budworm (Heliothis (syn. Heliocoverpa) virescens)
    The Geranium Budworm is a serious pest of cotton, tomato and flowers. Photographs of the larvae and damage caused, as well as a discussion of the problem, plants involved and control options are provided.
  • Edema (Oedema)
    The water-engourged cells of houseplants and greenhouse crops are indicative of this problem. Photographs of the symptoms and a discussion of the problem and its' control are provided.
  • Fasciations of the Plant World
    Fasciations are widespread phenomena reported in more than 100 vascular plant species
  • affecting dicots and monocots in 39 plant families and 86 genera.
  • Hollyhock Rust - Puccinia malvacearum
    Hollyhock rust is a serious problem in many ornamental plantings. Symptoms of this fungus initially appear as light yellow-orange spots on the upper surface of leaves of the hosts. The various hosts are listed and control options are provided.
  • The Hornworm
    About 1100 species of this insect are found around the world. The moths feed on nectar of many plants in late afternoon. The adult moths are mostly medium to large in size, and are sometimes referred to as hawk moths or hummingbird moths because of their rapid wing beats and hummingbird appearance. The larval stage (caterpillars) are known as hornworms and feed on many different plants.
  • Impatiens Necrotic Spot Virus (INSV)
    INSV is a devastating virus problem of many greenhouse plants. Photos of symptoms and a listing of known susceptible plants are provided.
  • A comparison of various mulches; temperature relationships and plant growth
    • A rubber-based mulch was compared with three bark/wood mulches and bare non-mulched soil to determine the surface temperatures of each, the soil temperature below each mulch, as well as the leaf temperature and overall growth of plants in the mulched areas. Surface mulch temperatures as high as 173 degrees Fahrenheit were recorded. Plant growth was not negatively affected at these temperatures. All mulches examined maintained soil temperatures consistently cooler than occurred in non-mulched soil.
  • Slime Mold - Myxomycetes - a problem associated with organic mulches
    This strange colorful growth on bark mulches is often thought to be due to a sick dog. A photo of one species of fungi (Myxomycetes) and a discussion of the Myxomycetes is provided.