Garden Pests (17)

Identify first, then choose the least toxic fix

The 17 pests covered here are managed on the integrated pest management (IPM) principle, and the order matters more than the list. Identification comes first, because the majority of failed treatments are treatments aimed at the wrong organism — a sucking insect mistaken for a chewing one, a disease mistaken for an insect, or an abiotic problem such as sunscald or a nutrient deficiency mistaken for either. Chewing damage that appears overnight is a different problem from stippled, discoloured leaves that develop over a week, and the two need opposite responses.

Once you have the pest, the IPM sequence runs from least to most disruptive: cultural controls first (remove infested material, adjust watering and nitrogen, rotate crops, time plantings to avoid a pest’s peak), then mechanical and physical (hand-picking, water blasts, barriers, row cover, traps), then biological and low-toxicity sprays (beneficial insects, soap, neem, Bt, diatomaceous earth), and only then conventional products. The reason to work in that order is not sentiment — it is that broad-spectrum products kill the predators and parasitoids that were already suppressing the pest, and a sprayed garden often rebounds to a worse infestation than the one that prompted the spray.

What each pest page gives you

Each page describes the signs well enough to confirm an identification, the damage pattern the pest produces, and an organic-first control list followed by conventional options. Where a pest has multiple generations or a specific vulnerable stage — the point at which it is newly hatched, soft-bodied, and easiest to control — the timing advice is the most valuable part of the page, because the same product applied two weeks late does nothing. Prevention is listed separately and is usually the section that changes the following season: sanitation at the end of the year, rotation, and habitat for beneficials all work before the pest appears rather than after.

Regional pressure is a real variable, which is why the pest and host pages cross-reference the state guides and the state-filtered finder. A pest with one generation a year in a cool climate can have three or four in a warm one, and that changes how much a single intervention accomplishes. The pest-by-host sheets narrow the same guidance to the specific crop in front of you, which is usually faster than starting from the pest.

Before you treat

Confirm that the product is labelled for the crop, the pest, and the site, and that it is permitted where you live — pollinator protections and local restrictions vary by state and municipality, and several active ingredients are restricted or banned for home use in some places. Apply to the correct life stage, in the correct conditions (most sprays need calm air and moderate temperature, and spraying in heat or full sun can burn foliage), and never tank-mix products that the labels do not permit together. The label on the container is the only version of the instruction that governs your use, and an extension office can confirm a diagnosis before you buy anything.

Keep a written record of what you saw and what you did, using the pest scouting log. Pests cycle, and a season of notes is what turns guesswork into a schedule — most experienced gardeners are not better at spotting problems, they simply know from their own records which week a given pest reliably arrives on which crop.