One of the joys of gardening is to visit your young plants to see the progress they are making towards producing the flowers, leaves, and vegetables you are hoping to enjoy. But what if you go out one morning to discover damaged or stunted growth, suspicious holes in leaves, or even plants that have toppled over as though visited by the Grim Reaper? When this happens you probably have insect invaders in your garden beds.
Know Your Enemy
As in any battle, you need to know the enemy. Here are a handful of the top garden pests you may see in your area.
Aphids –These little pear-shaped sucking insects are one of the earliest pests to appear in spring. Most are light green or yellow although some species come in other colors. These slow moving insects start by feeding on the underside of leaves but quickly graduate to the tender new shoots that appear during the growing season. If left unchecked, aphids will stunt growth and deform fruits and vegetables.
Cabbage Loopers – These are the light green caterpillars of the white cabbage moth. They move by bringing their back end up to the front, forming a horseshoe shaped loop, and then extending their front end forward. Cabbage loopers feed on members of the cole family – cabbages, broccoli, cauliflower, kale, and Brussels sprouts. The first sign that cabbage loopers are attacking is the appearance of small holes in the leaves.
Leafhoppers –Leafhoppers are generally light green sucking insects. They create clusters of small white spots on leaves. Leafhoppers are agile, moving quickly forward, backward, or sideways. If left untreated leafhoppers can cause leaves to curl or become stunted.
Four-Line Beetles – This is another fast-moving sucking insect. They leave behind clusters of black spots on young leaves. Although their damage is rarely serious, all those spots on spring growth are annoying and unsightly.
Spider Mites – Of all the common plant pests, I think none is more mis-identified – or missed altogether – than spider mites. Gardeners can easily miss the tell-tale signs of small amounts of webbing along the stem or tiny white speckling along the veins of a leaf that signal their presence. Flip the leaf over and if you look very carefully (a magnifying glass will help) you will find the tiny spider mites.
Mealybugs – If you see tiny cotton-like tufts in the joint between leaves and the stems you’ve got mealybugs. The insect hides under all that white fluff but don’t be fooled by its size. Mealybugs can cause serious damage.
Three Smart Ways to Combat These Critters
This year while you’re out in the garden, keep an eye out for the signs that these sucking and chewing insects are on the attack. Early detection followed by the careful use of an organic pesticide will keep them in check.
Clip off the Problem – If the infestation is small you can also clip off and destroy the infected branches. Do not compost infected materials. Home compost piles are rarely hot enough (over 120 degrees) to effectively kill the adults and their eggs. A too-cool compost pile can become a safe harbor through winter for these pests.
A Blast from the Hose – All gardeners suffer occasionally from an invasion of aphids, mealybugs, and other sucking insects in the edible garden. When this happens, don’t start with chemicals – even the eco-friendly insecticidal soap. Instead turn on the water and use a sharp spray to dislodge the critters from your plants. This does two things. First it blasts those slow moving insects far away from your roses and oregano. Then, as a bonus, the violent eviction can catch the insect in the act of feeding and break off their sucking mouth parts. Texas A&M estimates that about 90% of sucking insects attacked with a hose are put out of action.
Eco-Friendly Sprays – In grandmother’s time it was popular to spray poison to kill insects, the more deadly the better. However we are now more aware that this “scorched earth” policy has long-term negative effects when used to excess. It also kills the beneficial insects along with the harmful ones. Today we seek to solve our insect pest problems with as little danger to the environment as possible. Here are a few options for you as you fight insect infestations.
- Insecticidal Soap – Possibly the best spray to use for most problems is insecticidal soap. It works by breaking down the outer waxy coating of the insect exoskeleton, causing the insect to dehydrate and die. It only works by direct contact so you need to spray to coat the top and underside of tender growth and coat as many insects as possible. Repeat daily until they are gone.
- Neem Oil – This yellow-brown oil comes from the neem tree. It is not an insecticide but reduces feeding and acts as a repellant. It is slower to produce results than insecticidal soap but has a longer effective life. As with insecticidal, spray the top and bottom of the leaves. Don’t forget to hit the leaf joints where insects can hide.
- Spinosad – the Spinosad is a natural substance extracted from soil bacteria. It attacks the insect’s nervous system, leading to paralysis and death within 48 hours. Avoid spraying Spinosad on flowers because it can be harmful to the bees that pollinate your crops.
- Bacillus thuringiensis (Bt) – You have probably seen pesticides for sale featuring Bt. This is a family of chemicals extracted from a naturally occurring microbe. It acts when eaten by insects. It breaks down the digestive system, causing the insect to quickly starve and die. Read the Bt package labels carefully and use as directed.
Don’t let those chewing and sucking insects get the upper hand in your garden. Fight them with these eco-friendly pesticides and reap a healthy, delicious crop from your garden.