Delphinium flowers beautify the summer garden with showy, spiky blooms on a tall, sometimes towering stem. One commonly thinks of delphinium plants as having true blue flowers, which is the most common color, but they come in a range of other shades, including pink, lavender, red, white, and yellow. Blooms may be single or double. Delphinium planting is normally at the back of the bed, where flower spikes can reach 2 to 6 feet tall. Delphinium flowers are often planted in masses or groups. Shorter varieties are useful in other areas of the garden.
Delphinium plants prefer moist, cool summers and do not fare well in hot, dry weather. In cooler climates, grow delphinium plants in a sunny area. Gentle morning sun is preferable to the delphinium plants, which are picky about extreme differences in temperatures. Provide afternoon shade, especially when planted in hotter zones. If the gardener provides these conditions, the showy blooms are sure to appear.
Plant this specimen in the spring. Prepare the soil, mixing in 2 to 4 inches of compost. Dig a hole in the garden that allows the root crown to be covered with 1-2 inches of soil. Delphinium plants need well-draining soil that is consistently moist and will not dry out. Mulch helps retain moisture and keeps roots cool. This plant will appreciate soil that is neutral to slightly alkaline. In the spring, broadcast lime, wood ashes, or a mixture of the two to ensure an alkaline environment. Care of delphinium should include regular fertilization in spring when the plant begins to grow, and during the flowering period. Work in well-composted organic material such as rotted cow manure, or use a basic 10-10-10 granular fertilizer..
An important aspect of caring for the thought-to-be-difficult delphinium is deadheading the first blooms in early summer. Remove flower stalks when blooms are spent. When all blooms are removed and moisture and fertilization requirements are met, the gardener can expect bountiful blooms in late summer or early autumn.