The first thing to look out for are signs of plant stress, which include the following.

  • Wilting leaves/dry & stiff or crackling leaves can be a sign of not enough water
  • Yellowing leaves can be a sign of over-watering; NOTE that deciduous plants tend to yellow naturally before shedding their leaves, and also that yellow leaves can be an indication of a deficiency of some kind
  • Abnormal discoloration or texture (brown, black, or white spots, mildew/mold) can be a sign of fungal, pest, or other disease
  • Nutrient toxicity (too much fertilizer) is often shown by abnormal growth, yellow plants, discolored leaves, or death of parts of your plant or the entire plant
  • Burned foliage on a specific area of a plant can be a sign of contact with an herbicide or even animal urine


Stressed plants are often targeted by pests, some of which are listed as follows.

  • Aphids are very common sucking insect and are very easy to spot; small, pear-shaped, most often green or brown (sometimes black, yellow, or gray), and clustered in large groups; a sticky substance known as honey-dew will cover the affected areas of the plant, which can cause fungal diseases, such as sooty mold
  • Whiteflies are a soft-bodied winged insects, related to aphids and mealybugs, who also suck plant juices, causing similar problems to those of aphids; they will also leave a residue of honeydew and often lay their eggs on the undersides of leaves
  • Spider mites are an arachnid that often show up in dry, dusty conditions (houseplants often fall victim to spider mites); signs will be yellow spots that grow larger as mites feed on juices from the plant, as well as fine silky webs woven around leaves and stems
  • Tomato hornworms are very large caterpillars with horn-like tails; often found on tomatoes (though not exclusively); can cause excessive damage to plants, including leaves and fruit
  • Cucumber beetles are chewing insects that resemble green ladybugs; often found on edibles, such as squash and cucumbers, but can also be found on flowering perennials like dahlias; in addition to damage down by chewing/eating, they can also transmit bacterial wilt


Other plant maladies to look out for.

  • Powdery mildew is indicated by dusty splotches of white or gray powder on the leaves and stems of infected plants
  • Leaf spot is very common on tomatoes (though not exclusively), showing up as dark spots, often first on the underside of lower leaves before spreading
  • Gray mold is often caused by excess moisture, often showing up as white spots at first, progressing to excessive gray or brown mold covering leaves or fruit
  • Fire blight can quickly kill your plant, forming dark cankers that spread until the plant is destroyed


Some solutions to these problems.

  • Hosing down your plants can suffice to get rid of aphids, but in excessive cases Neem Oil, Pest Fighter, or Ladybugs should be used
  • Neem is also great for getting rid of whitefly, spider mites, powdery mildew, blackspot, etc.
  • Hornworm (and other caterpillars & worms) can be taken care of with BT Biological insecticide
  • Praying mantids are voracious carnivores that will indiscriminately devour anything they can fit in their clutches
  • Dust your houseplants to keep spider mites at bay
  • Get a good moisture meter to avoid overwatering (mold, yellow leaves, etc.), as well as not watering enough
  • Release ladybugs around dusk or dawn, preferably after they’ve been in the refrigerator for a while, wet down the area; the more pests they have to feed on the longer they will stick around
  • In the case of fire blight, all infected areas must be assiduously removed with a good pair of pruners; EACH TIME you cut you will have to dip the blade of your pruners in a mixture of bleach and water to avoid spreading the bacteria; after infected areas are cut away, avoid routine pruning for a while, as well as fertilizing