I had to re cut the stem of the one Delphinium that wouldn't take up water about four times and then I finally put it in warm water with extra preservative and it snapped out of it and took up water beautifully. Untreated, the spots grow larger and larger until they eventually turn the entire leaf black. Application of insecticidal soap twice a week is quite effective in removal of these pests. Black leaf spots are caused by small mites called cyclamen mites, which devour parts of the leaves and stems of the delphinium plant. Delphinium is a stately plant with tall, spiky blooms that beautify the garden in a big way during the early summer months. While difficult to treat with bactericides, a copper fungicide, like this one from Arbico Organics , can help you to manage bacterial leaf spot. Leaf Problems. As its name suggests, bacterial leaf spot causes small black spots to appear on delphinium leaves. Well, I have a update on my wilted Delphinium. Although these hardy perennials are easy to get along with and require a minimum of care, a few simple steps will ensure they survive winter cold unscathed. Deadhead the rest of the blooms since producing seed expends the plants energy. Preparing Delphinium Plants for Winter I usually let one portion of the plant go to seed and scatter those. Stems should be … It may rebloom but this species is short lived and produces seed very quickly. I kept it in a vase in the house to see how it would do and it last over a week. Your D. to the right in the last pic is Delphinium grandiflorum. Delphiniums come in dwarf, medium, and tall sizes, and are commonly found in the following varieties: Belladonna delphinium: The belladonna group is the … Distorted, curly leaves are caused by aphids or plant lice. To weather the winter safely and to ensure a full bloom for the following year, the delphinium must be cut back hard. Suddenly, practically overnight, it looks like it's dying: leaves all wilting and brown. The delphinium is one of the few plants that will flower to “exhaustion” and this sequence will allow the plant attain its best. Plants in the Delphinium genus are commonly known as larkspur, a name shared with plants in the Consolida genus; so, when purchasing your delphinium, make sure you're not accidentally buying an annual species of Consolida instead. Wintering. I have a Delphinium that I planted (large container) three months ago, and it's been a huge, thriving plant with lots of blooms till this week.