Delphinium Delphinium 'Susan Edmunds' (PBR) (d)

Water

Larkspur, commonly known as Delphinium, should be watered deeply and regularly, especially during dry periods to encourage deep root systems. Aim to water once a week, providing about 1 to 1.5 inches of water each time which equates to around 2 to 3 gallons, depending on the size and maturity of the plant. Be cautious not to overwater, as standing water can lead to root rot. During peak summer heat, check moisture levels and increase watering frequency if the top inch of soil feels dry. In cooler months, reduce the amount of water to prevent soggy soil.

Light

Larkspur thrives in locations that receive full sun for at least 6 to 8 hours a day. The best spot for this plant is in an area with clear exposure to direct sunlight, ensuring good flower development and strong stems. While it can tolerate some light shade, too much shade can lead to weak growth and a reduction in blooming.

Temperature

Larkspur prefers moderate temperatures and can generally withstand the climate in USDA hardiness zones 3 through 8. Ideally, they flourish in daytime temperatures around 65°F to 75°F and can tolerate minimum temperatures down to about -30°F in winter dormancy. They may struggle in regions where the summer temperature exceeds 85°F for prolonged periods.

Pruning

Pruning larkspur helps to encourage a second bloom and maintain its attractive form. Deadhead spent flowers regularly to promote new blooms. After the first wave of blooming, cut the flower stalks back by one-third to one-half to stimulate a second bloom period. The best time for more extensive pruning is in late winter or early spring when new growth begins.

Cleaning

As needed

Soil

The Larkspur (common name for Delphinium 'Susan Edmunds') thrives in a soil mix that is well-draining, fertile, and humus-rich. A mixture of loamy soil with added compost or well-rotted manure can provide the nutrients and structure necessary for optimal growth. The soil pH should be slightly alkaline, around 7.0 to 7.5. It is essential to ensure the soil is not waterlogged to prevent root rot, yet it should retain enough moisture to support the plant's growth.

Repotting

Larkspur plants such as Delphinium 'Susan Edmunds' do not typically require frequent repotting as they are perennial in nature and are often grown directly in the garden soil. If grown in containers, repotting should be done every 2 to 3 years or when the plant has outgrown its current pot. Care should be taken to disturb the roots as little as possible during the process.

Humidity & Misting

Larkspurs, including the Delphinium 'Susan Edmunds', prefer moderate humidity levels. While they tolerate a range of humidity conditions, they perform best when the air is not too dry. Excessive humidity can encourage fungal diseases such as powdery mildew, so ensure good air circulation to help maintain a balanced humidity around the plants.

Suitable locations

• Indoor

  Provide Larkspurs with ample light and avoid high temperature and humidity.

• Outdoor

  Plant Larkspurs in full sun, provide rich soil and good drainage.

• Hardiness zone

  3-7 USDA

Life cycle

Delphinium 'Susan Edmunds' begins its life cycle as a seed, which, when sown in moist soil and with adequate warmth, germinates to produce small seedlings. The seedlings grow rapidly, developing a rosette of basal leaves in their first year, and may form a short spike if conditions are favorable. In subsequent years, this perennial plant resumes growth in spring, sending up taller flower spikes from the crown that can reach up to several feet in height, and blooms with densely packed florets in shades of blue or purple. After flowering, which usually occurs in early to midsummer, seeds develop and are dispersed, completing the reproductive phase. Over time, the plant may form larger clumps as it matures, with multiple flowering stems. In winter, the above-ground parts of the Delphinium may die back, with the plant overwintering as a root crown to begin the cycle anew the following spring.

Propogation

• Propogation time

  Spring to Summer

• Propogation: Delphinium 'Susan Edmunds', commonly known as Larkspur, is most effectively propagated through division, which typically takes place in the early spring as the plant emerges from dormancy or in the late fall after the plant has finished blooming and the foliage has died back. To propagate by division, carefully dig up the entire plant, ensuring you keep a good amount of root systems intact. Using a sharp, clean knife or spade, you should divide the root ball into smaller sections, each with several growth points or buds. Each section should then be replanted in a hole that is just as deep but wider than the root ball. Water the newly planted divisions thoroughly, providing an inch (2.54 cm) of water per week unless there is sufficient rain. These divisions will grow into new plants that are genetically identical to the parent plant, maintaining the unique characteristics of the 'Susan Edmunds' variety.