Sowing and care guidelines
Start Delphinium nudicaule seeds after last frost, or in mild-winter climates in autumn. For better germination, pre-chill seeds in a sealed bag with slightly moist medium before sowing. Site in full sun, giving light afternoon shade where summers are hot. Use a well-drained, moderately fertile soil and avoid waterlogging. Sow thinly and maintain even moisture; seedlings prefer cool conditions and steady airflow. Space plants to prevent crowding, as this compact to medium delphinium dislikes stagnant, humid pockets. Water deeply but infrequently once established, and mulch lightly to keep roots cool. Deadhead spent spikes to extend display. Note: all parts are potentially toxic if ingested; handle and site with care.
- Suitable for containers with free-draining compost and regular, careful watering.
- Attractive to pollinating insects when in bloom.
- Valued for ornamental display of airy spikes and vivid colour.
How do I grow Delphinium nudicaule (scarlet larkspur) from seed?
Sow fresh seed for best results. Pre-chill (see below), then sow on the surface of moist, sterile seed compost and barely cover with a fine layer of vermiculite or grit (about 1–2 mm). Keep evenly moist and cool until germination. Once seedlings have true leaves, prick out to small pots, grow on in bright light with good air circulation, and acclimatise gradually before planting out. Choose a site with full sun and light afternoon shade where summers are hot, in well-drained, moderately fertile soil. Water regularly but avoid waterlogging. Deadhead to extend the display, or leave some seed heads to ripen if self-seeding is desired. As a compact-to-medium perennial, it suits mixed borders and naturalistic plantings.
Do Delphinium nudicaule seeds need stratification, and how do I do it?
Cold stratification improves germination. Mix seeds with slightly moist vermiculite, sand, or a folded damp paper towel, seal in a labelled bag, and refrigerate at roughly 1–5°C for 2–4 weeks. After chilling, sow promptly on moist compost, barely cover, and keep in cool, bright conditions; many delphiniums germinate best in cooler temperatures rather than warmth. Avoid letting the medium dry out during this period. Alternatively, autumn sowing outdoors in mild-winter climates can provide a natural chill. Use fresh seed where possible, as viability declines with age.
When should I sow scarlet larkspur in relation to the last frost?
Sow indoors in late winter to early spring so seedlings are ready to plant out after the last frost, or direct-sow outdoors once the risk of frost has passed and the soil is workable. In areas with mild winters, autumn sowing can be successful, allowing seedlings to establish in cool weather and bloom earlier the following season. Whether sowing indoors or out, aim for cool germination conditions and protect young plants from late cold snaps or extreme heat while they establish.
What sun, soil, and spacing does scarlet larkspur prefer?
Provide full sun, with light afternoon shade where summers are hot, to balance flowering and plant health. Grow in well-drained, moderately fertile soil; enrich lean ground with organic matter but avoid heavy fertilisation, which can cause weak growth. Good drainage is essential—avoid waterlogged sites. Space plants to allow airflow and prevent crowding; 25–35 cm between plants is a practical guide for compact-to-medium growth. Mulch lightly to conserve moisture without covering the crown, and water during dry spells, letting the surface dry slightly between waterings.
Can I grow larkspur in containers, and how tall will Delphinium nudicaule get?
Yes, scarlet larkspur grows well in containers if drainage is excellent. Choose a pot at least 25–30 cm wide and deep with ample drainage holes, and use a free-draining, peat-free mix amended with grit or perlite. Water thoroughly, then allow the top few centimetres to dry slightly before watering again, avoiding soggy compost. Feed lightly in spring with a balanced, slow-release fertiliser. Plants are compact to medium in height, typically flowering on stems around 30–60 cm tall, and may benefit from discreet support in windy positions.
Is larkspur poisonous to pets, does it self-seed, and is it pollinator-friendly?
All parts of Delphinium nudicaule are considered poisonous if ingested, so situate plants where pets and grazing animals cannot easily chew them, and dispose of prunings responsibly. In suitable conditions it can self-seed: allow some flower spikes to set and drop seed, then thin or transplant volunteers where needed; deadhead promptly if self-sowing is not desired. The nectar-filled spurred flowers are attractive to pollinating insects, supporting garden biodiversity. As a perennial larkspur for borders, it pairs well with other sun-loving, well-drained perennials to create a long-season display with wildlife value.
Guidance provided here is general and may need adapting to local microclimate, soil, and seasonal conditions. For precise sowing, spacing, and care, refer to the instructions on each product page, which reflect the specific selection offered. Seeds are sourced from established producers and handled under quality controls aligned with applicable industry standards. Germination and performance can vary with handling and environment; interpret recommendations in the context of site conditions and prevailing weather patterns.
Scarlet Larkspur Seed Sowing Guide
Delphinium nudicaule seeds offer vivid scarlet spires on compact plants suited to free-draining soils. Sow after last frost when soil is workable; in mild climates, autumn sowing may be possible. For improved germination, provide cool, moist stratification for 2–4 weeks before sowing. Use a fine, well-aerated seed mix, sow thinly, and cover very lightly; small seeds need only a dusting. Maintain even moisture without waterlogging and cool temperatures around 10–15°C during germination. Grow in full sun where summers are mild or with light afternoon shade in hotter conditions. Transplant carefully once true leaves appear, disturbing roots as little as possible, and space plants 20–30 cm apart. Water regularly during establishment, then allow the surface to dry slightly between waterings. Deadhead spent spikes to keep plants tidy and encourage repeat flowering. A sheltered position helps in windy sites. Seedlings appreciate good air movement and moderate fertility for sturdy growth. SeedsChoice
€5,95
