Greetings from the garden bed. We, the Black-eyed Susans (*Rudbeckia hirta*), stand tall and bright, offering our golden-yellow petals and dark central cones to the summer sun. While we are a resilient and largely trouble-free group, we are not without our share of uninvited guests. From our perspective, these pests disrupt our growth and mar our beauty. Here is a detailed account of our most common adversaries and the treatments we humbly suggest.
Our tender new stems and the undersides of our leaves often become gathering grounds for small, soft-bodied insects called aphids. They pierce our tissues with their needle-like mouths to siphon our vital sap. This draining weakens us, causing our leaves to curl, yellow, and distort. Furthermore, they excrete a sticky substance called honeydew, which attracts sooty mold and can interfere with our photosynthesis. A strong blast of water from a hose is often all it takes to dislodge these fragile pests. For more persistent colonies, we welcome the application of insecticidal soap or neem oil, which suffocates them without leaving harmful residues that could affect our pollinators.
One of our most frustrating foes is the four-lined plant bug. Their nymphs and adults feed on the sap from our leaves, but their method is particularly destructive. They inject a toxic saliva as they feed, which kills the plant cells in small, circular areas. This results in distinctive circular brown or black spots that can eventually cause the leaf tissue to fall out, leaving us looking tattered and skeletonized. They are most active in late spring. Picking them off by hand is effective if their numbers are low. As they are sensitive to many treatments, a thorough spraying of neem oil can help deter them and disrupt their life cycle.
Some of our challenges exist entirely out of sight, beneath the soil. Microscopic roundworms called root-knot nematodes can infest the soil around our roots. They invade our root systems, causing the formation of galls (swellings) that disrupt our ability to uptake water and nutrients. Above ground, this manifests as stunted growth, wilting on hot days despite adequate water, and a general yellowing or decline in our vigor. The best treatment is prevention through crop rotation and the planting of nematode-resistant companion plants. For an existing infestation, enriching the soil with organic compost can encourage beneficial fungi and microbes that will help keep these subterranean pests in check.
In mid-summer, we often face the metallic gleam of Japanese beetles. These beetles are voracious feeders that skeletonize our leaves and, most distressingly, devour our beautiful petals. They can quickly turn a lush, flowering plant into a ragged mess. The most direct and immediate treatment is to hand-pick them in the early morning when they are sluggish and drop them into a bucket of soapy water. We advise against using pheromone traps, as these often attract more beetles to the area than they catch, worsening the problem for all nearby plants.
Though technically a fungal disease and not an insect pest, powdery mildew is a condition that affects us as if we were under pestilent siege. It appears as a white or gray powdery coating on our leaves and stems, hindering our sunlight absorption and overall health. It thrives in humid conditions with poor air circulation. To assist us, please ensure we are spaced adequately apart to allow air to flow between our stems. Water us at the base in the morning so our leaves have time to dry. If an infection occurs, a homemade spray of one tablespoon of baking soda, one-half teaspoon of liquid soap, and one gallon of water can be an effective remedy.
