Dark spur (Latin Delphinium) is a very popular garden perennial that captures the viewer's eye with its racemose or paniculate inflorescences. Depending on the species and variety, the flowering plants reach a height of between 70 and 180 centimeters and a width of 30 to 60 centimeters. Most proven garden delphiniums reach an average height of between 120 and 150 centimeters. With the right care, the perennial will bloom all summer long.
How do I properly care for my delphinium?
To best care for delphiniums, water regularly during the growing season, fertilize every 2-3 weeks, support flowering shoots, cut back spent shoots, and provide protection from pests and diseases. Pot culture and winter-hardy varieties ensure good wintering.
Do I have to water delphiniums regularly?
During the growing season you should water regularly, especially on hot days and in dry periods.
How often should delphiniums be fertilized?
Provide your delphinium with a liquid fertilizer for flowering plants about every two to three weeks. However, this measure is only necessary if your garden soil is not very nutrient-rich. If, on the other hand, you have very dark, humus-rich garden soil, one fertilization with compost, humus, etc. at the beginning of the season and another after the summer cut should be sufficient.
Should delphinium flower shoots be supported?
When the flower shoots form, you need to support them with bamboo canes or other sticks. Only dwarf varieties can survive without support.
What is the best way to cut delphiniums?
Young perennials are best thinned out to two to three flowering shoots so that the plants do not become exhausted due to excessive flowering. For older, established plants, however, you can leave five to seven flower shoots. Otherwise, the delphinium is cut back to just above the ground after the second flowering in autumn.
Can I encourage the delphinium to bloom a second time?
Yes, because plants that are heavily cut back immediately after flowering often develop a second flower in September/October. To do this, cut off the dead flower shoots just above the ground.
How is delphinium propagated?
The best way to propagate delphiniums depends on the variety. In principle, propagation is possible by sowing in spring (attention, delphinium is a cold germinator!) as well as by division in early spring or autumn and by semi-lignified cuttings.
Is delphinium particularly susceptible to certain pests or diseases?
Dark spur is susceptible to snail damage (the shoots in particular must be protected from snails!), powdery mildew, spider mites, leaf miner flies and rust fungi. Occasionally the delphinium mosaic virus occurs. As a rule, however, voracious snails and mildew cause the most problems.
Can you also cultivate delphiniums in a pot?
With sufficient nutrient supply (i.e. long-term fertilizer and regular application of liquid fertilizers), delphiniums also thrive in pots. A container culture is particularly useful if the soil in the garden is unsuitable or snails are a big problem.
Can I transplant planted delphiniums?
Yes, even older specimens can be transplanted without any problems. If such a measure is necessary, you can also make a division at the same time.
Is delphinium hardy?
Dark spurs planted in the garden are absolutely hardy.
How do delphiniums overwinter?
No special protective measures need to be taken to overwinter perennial delphiniums. Only with one- to two-year-old varieties should you leave the faded inflorescences so that the plants can sow themselves.
Tips & Tricks
Not only slug pellets (€9.00 on Amazon) and other chemical helpers protect against slugs, but also sawdust scattered thickly around the plant. Snails are also reluctant to overcome dry mulch made from crumbled horsetail. The silicon-containing herb also prevents fungal diseases (e.g. mildew).