Greetings from the garden bed. We, the Delphiniums, stand tall and proud, our majestic spires reaching for the sun. But our journey from seedling to bloom is fraught with challenges. To help you help us, here is a detailed account of the adversaries we face, from our perspective.
Our tender new growth and the undersides of our leaves are prime targets for tiny, soft-bodied invaders. Aphids are the most common. They cluster on our stems and buds, piercing our tissues to suck out our vital sap. This weakens us, causing our leaves to curl and distort. Worse, they excrete a sticky substance called honeydew, which attracts sooty mold and can interfere with our photosynthesis. Cyclamen mites are another microscopic foe, causing stunted, twisted, and blackened growth, particularly devastating to our youngest shoots.
Our beautiful, lush foliage is a tempting meal for several leaf-eating insects. The larvae of the Larkspur Leafminer (a type of fly) tunnel between the upper and lower surfaces of our leaves, creating unsightly white, serpentine trails that drain our energy. Slugs and snails are nocturnal raiders that leave behind ragged holes in our leaves and a tell-tale slimy trail, especially during damp weather. They can quickly reduce our foliage to tatters if left unchecked.
Some of the most dangerous threats attack us at our foundation. Borers, like the larvae of certain moths, can tunnel into our crowns and flower stalks, causing entire stems to wilt and collapse suddenly. At ground level, cutworms will sever our young seedlings at the base, a heartbreaking end before we've even begun to grow. Our root systems are also vulnerable to microscopic roundworms called nematodes, which cause galls, stunting, and a general decline in our vigor.
Excessive moisture on our leaves and crowns is our greatest weakness and the primary cause of disease. Powdery Mildew appears as a white, powdery coating on our foliage, hindering our ability to breathe and photosynthesize in humid conditions with poor air circulation. More severe are Crown and Root Rot and Botrytis Blight (gray mold). These pathogens thrive in wet, cool conditions, causing a soft, brown decay at our base or a fuzzy gray mold on our flowers and leaves, often leading to our complete collapse.
Beyond fungal issues, we are susceptible to Bacterial Leaf Spot, which causes dark, angular spots on our leaves, often with a yellowish halo. This bacterium spreads through water splash and can lead to significant leaf drop. Viruses, such as the Cucumber Mosaic Virus, are often transmitted by aphids. They cause a mosaic pattern of yellow mottling, stunting, and malformed growth. Once infected, there is no cure for us; we must be removed to protect our healthy neighbors.
