AsDelphinium,larkspur is considered anherbaceousperennial.
But asConsolida ajacis,it is considered an annual.
Larkspur is toxic to people and pets.
The Spruce / Autumn Wood
Planting
In USDA zones 2 through 9, plant larkspur in fall or spring.
Choose a spot that gets full sunlight.
you might either direct sow seeds or plant transplants.
Guardian Lavender Larkspur (Delphinium ‘Guardian Lavender’)Horst Sollinger / Getty Images
If transplanting, be sure to water in the plant thoroughly.
Light
Full sun is best for larkspur.
The plant needs between six and eight hours of sun daily.
Blue Mirror Larkspur (Delphinium ‘Blue Mirror’)Jackie Bale / Getty Images
Soil
Give them moist, cool, well-drained soil.
The soil can be kept cool and moist by furnishing withmulch.
Water
Water the plants once or twice a week.
Golden Larkspur (Delphinium Luteum)Hal Beral / Getty Images
Give the flowers an inch of water every time you water.
Consider recent rainfall and avoid watering if the plants are already wet.
Temperature and Humidity
Larkspur prefers cooler temperatures, which also triggers blooming.
The plant prefers mild summer-like conditions that are not humid, however, seedlings may prefer some humidity.
These plants are frost-tolerant and will survive the winter in zones as cold as zone 2.
Fertilizer
Fertilize your larkspur plants every spring withcompost.
This will be enough nutrients to get them through the growing season.
Types of Larkspur
When most gardeners think of larkspur, they think of a plant withblue flowers.
As you might see, there are many choices in blue larkspurs.
They differ in terms of hardiness, size, and the precise quality of the blue flower color.
Cuttings work best with perennial larkspur.
They grow tall and heavy, so they do well when potted in containers with wide bottoms.
It’s unnecessary to add organic matter to the soil for larkspur.
Larkspur is susceptible to diseases such as botrytis blight and crown rot.
Powdery mildew can also be a problem.
Deadheading spent flowers and stalks encourages blooming.
Dry soil will stunt the larkspur’s ability to bud and flower.
It’s a translucent mite that causes the plant to stop blooming.
This pop in of mite is difficult to control,.
Yellowing Leaves
The plant may have crown rot.
Look also for white webby material on the crown, which indicates crown rot.
Yellowing leaves also indicate a viral infection.
Deformed Plant
The plant likely has a virus, such as mosaic.
You will need to dispose of the diseased plant.
Touching the leaves and seeds of a larkspur plant can cause skin irritation.
Larkspur is often a tender perennial that comes back annually but only for a few seasons.
True larkspur is an annual which reseeds, but the same plant will not come back the next season.
Larkspur blooms in the early summer.
It can rebloom in late summer and early fall, as well.
North Carolina State Extension.
Delphinium elatum.Missouri Botanical Garden.
