Plant Health Page 1

  Plant Health

Plants grown under the proper conditions will be healthy plants.  What are the proper conditions?

  • Full sun plants in the sun, shade plants in the shade. 
    • Many full sun plants will still perform in part day sun.
    • Sun plants that don’t get enough sun will be stressed and more liable to attack by pests.  Shade plants in sun will get crispy leaves.
  • Adequate water
    • Prairie plants like purple coneflower and some bulbs will not do well under sprinkler systems.  They don’t need so much water.
    • Plants that don’t get enough water are stressed and more susceptible to insect attack and disease pressures.
    • Some plants, like LA Iris and bald cypress go both ways and will grow equally well in shallow water and on well-drained ground.
  • Fertile soil, built either with organic amendments or fertilizer application (or both).
  • Use a mulch
    • 3-4” of leaves, pine straw or bark, replenished as needed.
    • Mulch adds nutrients as it decomposes.
    • Mulch conserves moisture and makes a barrier against weed germination.

Sometimes severe weather makes plants problem-prone.

  • Too much rain fills oxygen spaces in soil and plants suffer.
  • Too little water stresses plants.
  • High humidity makes powdery mildew thrive.
  • High rainfall increases insect reproduction (and attacks).
  • High rainfall spreads disease by carrying spores across leaves.

Plans of attack:


  • Preventive sprays are only used for commercial production and tea roses.
  • For occasional outbreaks, identify your pest and spray the least toxic chemical.
    • Only spray when pests are there.  They are NOT there year-round.
    • Only spray the infested plants.
    • Follow the chemical label carefully and repeat as directed.
    • Alternate between 2 pesticides to avoid developing resistant super-bugs.
    • Don’t spray within 4 feet of bodies of water.
  • Carbaryl (Sevin) is low toxicity and kills anything that “chomps” when it eats a treated leaf.
  • Systemic insecticides (acephate, imidicloprid) are best for sap suckers like aphids, whiteflies and scale.  Do not use on vegetables and fruits unless it’s labeled for them.
  • Malathion – good basic contact insecticide (must get it on bug).
  • Organic insecticides:

Insecticidal soap – must get it on the insect; works best on soft bodied insects like aphids, whiteflies, spider mites, thrips.  Harmless to ladybugs & predators.

Neem – insect hormone disruptor for soft bodied insects.   Harmless to ladybugs & predators.                            Read On...