Asphodeline

( ass - FOH - del - ine )

At-A-Glance Information

Commonly called King's Spear or Jacob's Rod, this genus of flowering perennials includes species which need full sun or partial shade and regular water to perform well in the landscape. Native to the Middle East and the Mediterranean, Jacob's Rod forms a low clump of blue-green to dark green grassy leaves. In springtime, unbranched stems produce clusters of fragrant yellow or white flowers between reddish-brown bracts. Use these plants as taller flowers at the back of mixed beds and borders, along fence lines, massed in wildflower or pollinator gardens, or in containers on walkways or patios. Take care when planting these flowers in the garden, as plant parts of some species are mildly to moderately toxic to humans and pets, especially if ingested in large quantities.

Asphodeline species and varietals

The genus Asphodeline is included in the plant family Asphodelaceae, and includes 17 species. It was first formally described as a genus in 1830. These plants grow best in USDA hardiness zones 5 through 9 or Sunset growing zones 3b-24 (to find your zone, click here: Zone Map).

Asphodeline lutea (King's Spear, Jacob's Rod, Yellow Asphodel)
This plant is native to Europe and North Africa, and is commonly grown as an ornamental in gardens. Jacob's Rod produces yellow fragrant flowers in spring atop flowering stems that rise above foliage. Individual plants typically reach up to between 2 and 4 feet tall and 1 and 2 feet wide at maturity when in bloom.

Asphodeline tenuior (Thin Asphodeline)
This species is native to the Caucasus, Turkey, Russia, and Iran and produces yellow flowers. It is considered threatened in its native range. There are a few subspecies, one of which has white flowers that open from mauve-pink buds and have mauve stripes (pictured). To 10-20 inches tall when in bloom.

Caring for Asphodeline

Asphodeline is considered a low-maintenance, easy-care plant that likes to grow in moist, rich, well-draining soil. They prefer a soil pH of between 5.5 and 6.2; amend soil with organic material before planting, especially if local soil is heavy clay, infertile or does not drain well. Plant in full sun exposure; ideally they should get between 6 and 8 hours of sun each day, but they can also do well in partial shade (though they will not flower as profusely). Although at maturity Asphodeline plants are drought-tolerant, they do prefer soil that is kept relatively moist, especially during the active growth and flowering seasons. Feed Asphodeline yearly with a dressing of organic compost, adding some to the area before planting and working it into the soil. After planting, mulch around the base with organic mulching material to help retain soil moisture and suppress weed growth. Keep mulch away from the plant stems, as this can encourage an environment in which root rot issues develop.

​Remove spent flower spikes after they have faded (unless collecting seeds later in the season for propagation). This will encourage reblooms and maintain a neat appearance. Pruning these flowers also includes trimming back leggy or overgrown stems to encourage a bushier growth. These plants can be pruned back by a third towards the end of summertime to rejuvenate them for a fresh flush of growth. In cooler zones, plants may die back to the ground each winter. They will regrow in springtime, especially if root systems are mulched for extra frost protection. Every few years, especially if these plants are grown in a cramped area, they will need to be divided for ongoing health. For instructions on how to divide Asphodeline plants, see the Propagation section below. Asphodeline are perennials, able to live for between 3 and 5 years in the garden before needing to be replaced.

Propagation

The best way to propagate Asphodeline is through dividing existing plants. To propagate your King's Spear plant, follow the instructions below:

Propagating Asphodeline by Division
This type of propagation is relatively simple; you will need a clean shovel, mulch, fresh soil, compost and pots (12 inch pots are perfect, and these are only necessary if you will be saving divided plants for transporting elsewhere). Division is best done in very early spring (just as it has begun its new spring growth for the year). To propagate Jacob's Rod flowers by division, follow these steps:
  1. Using a shovel, dig up your existing plant. Start from the outside and work your way in to avoid damaging the root system. Once you have worked it up out of the ground, lay it out.
  2. Start to tease apart the roots with your fingers. Once the roots are untangled, separate your plant into segments, ensuring that each one has at least one thick rhizome section attached.
  3. Prepare your pot(s) or new planting site(s) with amended, well-draining soil. You can either bring in new soil or simply amend your existing soil with compost to complete this task. Then, plant your divided tubers about an inch under the soil surface and water thoroughly.
  4. Apply a thick layer of mulch over the new planting to protect it from cold weather as it acclimates to its new home.

Problems and Pests

Asphodeline plants can suffer from the following pests and diseases in the landscape:
  • Aphids
  • Mealybugs
  • Spider Mites
For more information on these pests and diseases, consult the following pages:
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Gallery

Asphodeline flowers are typically yellow, but there are some species and varietals with white flowers, as well.
King's Spear is featured in this informal pollinator garden.
These plants prefer either full sun or light shade, often growing along forest edges in their native range.

Videos

All about growing these flowers.

Resources

How to Grow Jacob's-Rod - Asphodeline
Asphodeline lutea
Wikipedia: Asphodeline
The New Sunset Western Garden Book: The Ultimate Gardening Guide (2012) - Page 175, Asphodeline lutea