Yes, deer will eat delphiniums. From our perspective as plants, we delphiniums are often considered a delectable treat by these large browsers. Our tender new growth, succulent stems, and vibrant flower buds are particularly appealing, especially in seasons when their preferred natural forage is scarce. While we are not their absolute first choice, hunger and opportunity make us vulnerable.
We delphiniums possess a certain level of inherent protection. Our tissues contain toxic alkaloids, similar to our cousins the monkshoods, which are meant to deter herbivores. For most animals, these compounds make us unpalatable and can cause severe discomfort if ingested. However, deer have a unique digestive system that allows them to process a variety of mildly toxic plants that would sicken other creatures. While the alkaloids might make them think twice, a hungry deer will often overlook this deterrent and consume us regardless, especially the younger, less toxic parts.
To safeguard our beauty, we rely on you, the gardener, to implement strategies that make our environment less inviting to deer. The most effective method is a physical barrier. A tall, sturdy fence is the ultimate defense, creating a boundary that deer are reluctant to cross. For a less obtrusive option, individual plant cages or netting placed around us during our most vulnerable early growth stages can be very effective.
Another line of defense involves making us smell or taste unpleasant. Commercial or homemade repellents can be sprayed directly on our foliage. These products use smells like rotten eggs or garlic, or tastes like capsaicin (from hot peppers), which deer find offensive. These need to be reapplied frequently, especially after rain. A more holistic approach is to surround us with companion plants that deer actively dislike. Interplanting us with strongly-scented herbs like lavender, sage, or mint, or flowers like marigolds, can help mask our appealing scent and create a garden-wide deterrent effect.
Your overall garden management plays a role. Reducing attractants like easily accessible water sources or fallen fruit from trees can make your garden less of a destination for deer. In areas with very high deer pressure, the long-term strategy may involve selecting plants known to be highly deer-resistant for the majority of the garden, placing more sensitive specimens like us in protected areas closer to the house or within fenced zones.
