Delphinium elatum Seeds | Yellow Delphinium
LATIN NAME: Delphinium elatum
COMMON NAME: Yellow Delphinium
Plant Profile
Getting yellow to stick in a tall garden delphinium is slow work, and the result is prized precisely because of that difficulty, which keeps the yellow strains a notch above the common blues in the seed catalogue. The New Zealand-bred New Millennium series has pushed the clearest gold furthest, and a few of its selections carry the warm tone without the violet grey that marks lesser yellows.
The yellow spike is worked chiefly by bumblebees that brace on the lower petals and probe the spur for nectar, and because the colour is rare in the genus the plant draws a different mix of insects than its blue siblings do. Letting a few spikes run to seed also feeds finches, which strip the angled seeds from the drying capsule in early autumn, so the plant earns its place twice over.
The pale gold spike lights up a border in a way the cooler colours cannot, and it pairs with silver and cream foliage better than the blues do, reading as sunlight made solid against the green.
Because the yellow forms stay a little shorter and lighter than the blues, a single plant in a deep container makes a fine patio specimen, provided the pot is heavy enough not to tip when the spike is in full flower. Use a loam-based mix rather than a peaty one, and keep the crown at the surface so the stem base stays dry through a wet spell, because the gold colour shows a rotten base faster than any other.
Science & Biotechnology
Where blue and red delphiniums load their petals with anthocyanins, the yellow sorts depend on carotenoid and flavone pigments that reflect in the yellow band of light. This is the same chemistry that yellows a marigold, and it is why the yellow delphinium sits apart from every other colour in the genus, built from a different class of molecule entirely.
Uses & Benefits
Like all delphiniums, the yellow sort carries diterpene alkaloids such as methyllycaconitine in its seed and young tissue, and the plant is toxic if eaten, a property shared by every colour in the genus. Gardeners should handle the cut stems with care and keep them from livestock, just as with the blue and red strains, because the pretty spike hides a serious dose.
Growing from Seed
Yellow delphiniums are selected for the warmest pale-gold tone the elatum line can reach, usually a soft buttery colour rather than a deep gold. Because the trait is recessive against the dominant blue pigments, keeping a yellow strain true demands steady roguing of any blue or violet off-type that appears, and a single blue seedling in a yellow row is pulled before it flowers.
The wild California larkspur Delphinium luteum is one of the few naturally yellow members of the genus, a rare coastal endemic that breeders have drawn on to nudge the garden hybrids toward gold. Its scarcity in the wild is a reminder of how unusual the colour is, and why a yellow delphinium seedling is something to treasure rather than take for granted.
Sow the large angled seed on a fine loam-and-sand mix and cover lightly, keeping it cool and just moist; fresh seed gives the strongest stand, since old seed is slow and uneven. Prick out the seedlings when they carry their second true leaf and grow them on in bright, airy conditions where the young plants toughen before they meet the open border.
Thin or transplant so each young plant has room, moving them on once the first true leaves are open and the seedling stands a few centimetres. Crowded seedlings make weak, spindly stems that will not carry a full yellow spike, and the gold colour shows thin, poor growth more honestly than a blue would.
Plant out when the young plant is about fifteen centimetres, setting the crown shallow, and mulch lightly so the base stays dry through frost. A dry crown is the key to the plant returning for a second, taller year of clearer yellow, because a wet winter base is what kills more delphiniums than any cold.
Our Take
I grow yellow delphinium where morning light catches the gold, near columbine and clematis tangutica for a shared airy grace. A Delphinium delavayi in a darker tone makes a good contrast behind it.
Related Reading
Gardeners who grow Yellow Delphinium often pair it with these related subjects: