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growing Larkspur from seed

It's Not Rocket Science! Defusing Myths About Larkspur's Challenging Nature

Has anyone ever told you that growing larkspur from seed is about as easy as finding botanical life on Mars? Maybe you've heard your neighbor swear up and down that the neighborhood nursery sold them a bill of goods and a bad batch of larkspur seedlings. Or maybe, after trying to get them off the ground yourself, you're certain your garden's just plain cursed.

Here's the deal. Haters are gonna hate. Ignorance breeds hate. And blaming evil spirits for a garden that's failed to launch...well, that's just gosh-durn silly.

The moon landing wasn't staged, and you don't need to raise Stanley Kubrick from the dead to give you a gorgeous patch o' larkspur in your yard. You just need to know a little bit about this stunning ornamental's germination needs. Once you have that nailed down, you're cleared for takeoff. In fact, "rocket" refers to the speed by which they grow and bloom.

Etymology & History of Larkspur

The most common larkspur species cultivated in North America is Consolida ajacis, commonly called "rocket larkspur" or "giant larkspur." Trailing behind is the similar "forked larkspur" (Consolida regalis). Both are very similar, but we'll default to C. ajacis as we blast through the basic growing recommendations for this popular garden ornamental.

  • Consolida ajacis is often confused with the delphinium plant. In fact, you might see them classified as Delphinium consolida. Nowadays, they have their very own, well-deserved genus.
  • Larkspurs are annuals, and delphiniums are perennials. But larkspur plants easily reseed, rejuvenating their "colonies" each season.
  • Delphiniums are more difficult to grow from seed, which is why—due to confusion between the plants—larkspurs' reputation for being tough to grow may be exaggerated.
  • Consolida, by the way, is Latin for "consolidate" or "make firm." Compounds from larkspur were once used as a blood clotting agent and healing salve.
  • Larkspur is a member of the Ranunculaceae (buttercup) family.
  • Rockets are pointy tubes of fire that send sports cars into space, or a whole lotta nasty to unsuspecting countries elsewhere on the planet.

Larkspur has easily naturalized throughout the world, and it's widely believed to hail from Asia, the Middle East, and Mediterranean Europe. According to The University of Arkansas' agricultural division, "Three species of larkspurs were introduced into English gardens from Italy between 1550 and 1573. They became instant hits and were frequently used in the first wave of pleasure gardens built during this period. They were introduced into American gardens during the pre-Revolutionary era."

Some botanists believe that larkspur had already naturalized in North America by the mid-16th century, so it's possible it arrived here long before European settlers...or maybe even before early seafaring explorers. For all we really know for certain, larkspur came to Earth on a meteor. That's kinda what we think happened with Bells of Ireland, at least.

Also: What's a "pleasure garden"? I bet you'd need one heck of a privacy fence if you're going to have one of those.

Larkspur's Role in Folklore & Herbalism

All parts of the larkspur plant are poisonous if ingested, but ancient Greek soldiers made a tincture from the plant's crushed seeds to control body lice. Probably those other lice, too. Larkspur poultices once treated wounds and hemorrhoids, and Native North Americans used the flowers as both a dye pigment and an insect repellent.

Since we wrote this post in mid-October, we figured we'd consult with Witchipedia to learn more about larkspur lore. According to them, the Trojan hero Ajax "slew himself after he dishonored himself in a temper when he did not receive the armor of Achilles, and larkspur sprang from his blood."

Perhaps because of its association with raging testosterone and armor, larkspur was a popular ingredient for spells intended to protect warriors, and Witchipedia hints that these spells are still used in the Craft to help police, fire, and aid workers... and in case these rituals fail miserably, larkspur is also used to honor the dead.

The flowers have horned-shaped "spurs," much like those of columbines. This upwardly-pointed appendage may be why larkspur was thought to repel scorpions as well as ghosts, evil spirits, and even thieves; folks hung bundles of dried larkspurs around their property for this purpose.

By the've probably noticed that we're working with two different themes here, but anyway you look at it, larkspurs—and their delphinium cousins—are out of this world.

Growing Larkspur in the Garden

When we think of flowers that grow on racemes—tall, slender stalks—we usually think of bell or tube-shaped blooms. Larkspurs look like they've had brightly-dyed aster-type blossoms pinned to their stalks.

Flower shapes vary. Some closely resemble dyed daisies, while others, like those on rocket larkspur, look like tiny orchids against five delicate, crepe-thin, color-matched sepals. They can be white, pink, violet, or blue, and some larkspur blooms are double-layered with a fluffy, ruffly appearance.

As we mentioned, rocket larkspur has inch-long pedicels (spurs) behind their 2" flower heads. The flowers are specialized to attract butterflies, hummingbirds, and other pollinators with a long reach.

Larkspur is an upright, non-mounding annual with feathery, deeply-lobed, palmate foliage. The lacy leaves grow to about 3" in width and length. The racemes grow up to a foot in height from stalks that may fork into 2 to 4 branches.

This plant is tougher than it looks, being moderately frost-tolerant in warmer climates.

USDA Hardiness Zones: Larkspur is suitable for zones 2 to 10. Grow larkspur in zone 10 in Larkspur, California, or in Larkspur, Colorado (5b). Move to a zone 2 region in Alaska and set up an off-grid camp and name it Larkspur just to make this attempt at cleverness actually work. Please.

Sunlight Preferences: Larkspur prefers full sun, but in the hottest zones it likes a little late afternoons shade.

Watering Requirements: Keep your larkspur beds consistently moist, but not wet.

Soil Preferences: Larkspur does well in the wild in medium-quality, well-drained soil, but it prefers nutrient-rich, compost-amended beds. It has a widely-tolerant pH range (5.7 to 7) with 6.5 being the sweet spot.

Plant Height: 24" to 48" tall

Plant Width: 12" to 18" spread

Bloom Period: Early June through mid-September in cooler zones; in hotter zones, they generally finish at the peak of summer.

Pests & Diseases: Due to its purported pest-repelling qualities, it's no surprise that larkspur is resilient to insects. It is susceptible to mildew and the leaf-yellowing Sclerotium rot, so make sure they're not too wet, and destroy any affected foliage.

Maintenance: Larkspur is a low-maintenance plant. There's not much you need to do to keep them pretty, though deadheading will tidy them up. If you don't want them to reseed themselves, remove spent flowers before their seeds develop. Taller racemes (stalks) might need staking in unsheltered areas. Once a week for the first few weeks after your larkspurs emerge, feed them a diluted solution (about 25%) of all-purpose, 10-10-10 fertilizer.

Harvesting: Larkspur is a popular fresh cut flower, and if you invert and suspend their flowery stems in a dry room with good air circulation, you'll end up with spectacular bundles of dried flowers...with the added bonus of a ghost-free home.

Companion Plants: Plant larkspur among spring bulbs so they'll help cover up spent foliage. It rarely reaches its maximum height of 4', so you can plant it in front of leggier plants, or simply grow it in masses. Try mixing it up with cleome, or planting larkspur in front of roses, cosmos, or echinacea!

Growing Larkspur from Seed

Remember... it's not as difficult as you've heard!

Prep your garden site by digging in some 10-10-10 or other balanced fertilizer to give your larkspur some extra kaboom, or add some well-rotted compost to your larkspur beds. We recommend direct-sowing your larkspur seeds since they're not easily transplanted from nursery pots. If you do decide to start them indoors, be sure to use biodegradable pots made from peat or folded newspaper, or try out some CowPots. (Yeah, you guessed it; they're made from poop!)

  • Seed Treatment: We recommend using the "paper towel" method of cold-stratification for a period of two weeks. While small, larkspur seeds are reasonably easy to handle (with gloves, please) and their wrinkled texture allows them to respond well to cold moisture treatments. However, this same increased surface area can cause seeds to dry out and lose their viability during storage.
  • When to Plant Outdoors: Early fall in warmer climates, or immediately after your last frost date in spring. Larkspur germinates best in cool weather, between 55°F and 65°F. Much warmer than that, and you'll have problems.
  • When to Plant Indoors: 8 to 10 weeks before your last frost. Be sure to keep your seedling pots in a cool, sunny spot.
  • Seed Depth: 1/4" deep
  • Seed Spacing: Space seeds or thin to 12" in each direction.
  • Days to Germination: 20 to 30 days in optimal weather and temperatures.

Though it may sound like we're trying to sell you more seeds, we strongly advise double (or triple) seeding each planting location or pot. Larkspur seeds are as slow to launch as are teenagers on a Monday morning, and sudden spring temperature spikes might wipe a few of them out before they emerge.

Let Seed Needs Help You Launch Your Garden

Larkspur is one of those plant seeds you want on hand well in advance of spring. They have a short shelf-life, so you'll want to be sure to purchase the freshest seeds possible. We often sell out, since we only order from our reputable, sustainable suppliers what we can expect to sell in a single year...and we stand by our products. That's how we've been able to keep our customers happy since our first giant leap into the seed business, and why it's important to us that you have a successful garden year after year.

Contact us if you'd like to order our rocket larkspur seeds, or if you'd like to request another larkspur variety!
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