Delphinium elatum
Growing calendar
Typical timing for central Japan (Kanto region). Shift it for your own climate, and record your actual dates.
Guides
- How to Sow Delphinium Seed: Freshness, Temperature, Depth and Growing On
- Delphinium Care: Thinning the Stems, Staking Every Spike and Feeding for Height
- Why Is My Delphinium Not Flowering? Short Spikes, Blind Shoots and the Autumn Repeat
- The Delphinium Year: What to Do from the First Shoots to the Autumn Cut-Back
- Delphinium Pests and Diseases: Slugs on the Spring Shoots, Mildew and Crown Rot
- How to Propagate Delphinium: Basal Cuttings, Division and Why Seedlings Vary
Common problems
Start from what you can see on the plant.
Pests and diseases (18)
Problems recorded for this plant, most serious first.
Bacterial Wilt
Disease
Leaves wilt while still green during the day and recover in the morning and evening; after a few days of this the plant dies. Cut the stem and stand it in water and a milky white bacterial ooze streams out in threads.
Powdery Mildew
Disease
White patches appear scattered on the upper leaf surface at first, then the whole leaf is coated in a white powder. Leaves later yellow, brown and die back, and reduced photosynthesis cuts growth and yield.
Late Blight
Disease
Dark green water-soaked lesions appear on the leaves and expand quickly into brown dead tissue. White mold forms on the underside and at the lesion edge, and dark brown lesions spread to stems and fruit.
Southern Blight
Disease
The stem rots at soil level and white silky mycelium spreads over the crown and the surrounding soil surface. Brown sclerotia the size of rapeseed then form and the plant wilts and dies rapidly.
Damping-off
Disease
The stem pinches in at soil level, turning water-soaked to brown and thin, and the seedling topples over. Infection before emergence makes the stand uneven with missing plants.
Bacterial Soft Rot
Disease
The crown or the head becomes water-soaked and soft, then collapses into a slimy mush. The rotting tissue gives off a distinctive foul odor.
Gray Mold
Disease
Water-soaked brown lesions form on flowers, fruit and leaves, densely covered by a fuzzy gray mold. Fruit rots and drops, and decay continues in storage after harvest.
Verticillium Wilt
Disease
Only one side of the lower leaves yellows and wilts, and the symptom moves up the plant. Stem vascular tissue turns pale brown and the plant dies without ever growing well.
Bacterial Spot
Disease
Small water-soaked spots appear on the leaves, later turning brown with yellowing around them. Fruit develops water-soaked or scabby spots from which rot spreads.
Leaf Spot
Disease
Small round brown to gray-white lesions appear on the lower leaves, the centers turning gray with tiny black specks. As they multiply the leaf yellows and drops early.
Downy Mildew
Disease
Pale yellow to yellow-brown angular lesions form on the upper leaf surface with a gray-purple mold in the matching spot underneath. Lesions merge, the leaves die back and the plant declines early.