Asparagus

( uh - SPAIR - ah - gus )

At-A-Glance Information

This genus of perennials, shrubs and vines grow in sun or partial shade and need regular water. There are about 150 types of Asparagus that are considered ornamental, many native to South Africa. Some have small flowers that are fragrant followed by colorful berries. Most will be greenest in partial shade, and tinge yellow in denser shade areas. These plants are damaged by frost, but will usually grow back completely from roots. Take care when planting these in the garden, as their berries are toxic to humans and pets; certain species are also considered invasive weeds. To learn about cultivating the edible crop Asparagus, visit the page linked below:

Asparagus (Crop)

Asparagus Species and Varietals

The genus Asparagus is the type genus in the plant family Asparagaceae, and includes 212 species. The best growing zones for Ornamental Asparagus are USDA hardiness zones 3-10 or Sunset growing zones 12-24, though this varies somewhat depending on the species. For more information, see the descriptions below. To find your zone, click here: Zone Map.

Asparagus acutifolius (Wild Asparagus, Spiny Asparagus, Lesser Asparagus)
This species is native to the Mediterranean, and typically reaches between 12 and 24 inches tall when mature. Foliage is feathery and branched, and has thorns. Flowers are greenish-white to yellowish, bell-shaped and form in small clusters in summertime. Blooms are followed by small green berries. Best in USDA hardiness zones 7-10.

Asparagus aethiopicus (Sprenger's Asparagus, Asparagus Fern, Asparagus Grass, Foxtail Fern, Ground Asparagus)
These perennial plants have tough stems sparsely covered with spines, and produce white to pinkish-white flowers in springtime. The blooms are followed by berries, which turn red in wintertime. These plants are native to southern areas in South Africa, and have been declared a weed in many areas of the world. Best in USDA hardiness zones 9-11; considered an invasive weed in many parts of the world, including California.

Asparagus africanus (African Asparagus, Bush Asparagus, Wild Asparagus, Climbing Asparagus Fern, Ornamental Asparagus, Sparrow Grass, Haakdoring, Katdoring, Umathunga, Umthunzi)
Natives of Africa, these plants are spiny shrubs that reach up to 3.3 feet tall and produce stems that can reach up to 40 feet long. Foliage is fern-like and green, and flowers are white and small. They bloom in clusters in August and December in the plant's native range. Red fruits follow flowers. Best in USDA zones 7b-9b. Climbing Asparagus Fern is considered to be invasive in many areas, including Australia and the western coast of the United States.

Asparagus asparagoides (Smilax Asparagus, Bridal-Veil Creeper, Gnarboola, Bridal Creeper, African Asparagus Fern)
This species of Asparagus has spineless stems that reach 20 feet or longer; and the 'leaves' are broad and glossy green. Tiny white flowers that bloom in spring are fragrant and followed by blue berries. Roots can survive long periods of drought, though it will die back in summertime and regrow from roots. Unless trained, this plant will become a tangled mass of greenery. Similax Asparagus can escape gardens and become invasive through volunteer seedlings spread by bird activity. Varietal 'Myrtifolius' ('Baby Simlax') is a more attractive form of this species. Best in USDA zones 7b-10b. Considered to be a highly invasive weed in Australia, New Zealand, and California.

Asparagus cochinchinensis (Chinese Asparagus, Chinese Tuber Asparagus, Asparagus Root)
These plants are native to eastern Asia, including the Philippines, Japan and Vietnam. The roots and stems of these plants are used in traditional Chinese and Korean medicine. Individual plants reach 5 feet by 3 feet, with trailing, shiny stems and needle-like green foliage. This species does well in USDA hardiness zones 5a-9b.

Asparagus crispus (Asparagus declinatus) (Basket Asparagus, Bridal Veil Creeper, Weeping Asparagus, Pale Berry Asparagus Fern, South African Creeper)
This variety of Asparagus is an airy, graceful plant great for using in hanging baskets. The evergreen leaves are bright green and very small. This species is native to southern Africa, and is widely cultivated around the globe. Considered invasive in Australia.

Asparagus densiflorus (Foxtail Fern Asparagus, Plume Fern, Asparagus Fern)
The evergreen leaves are bright green and very small. This species is native to southern Africa, and is widely cultivated around the globe. This species grows best in USDA zones 9-11 and Sunset zones 12-24, H1 and H2. The species is less commonly grown than its varietals, which includes 'Myers', a 3-4 foot clumper with ferny foliage. This species is considered invasive in Florida, Texas, California and Hawai'i, as well as many other areas across the globe.

Asparagus falcatus (Sickle-Thorn Asparagus, Large Forest Asparagus, Imbekazana, Doringtou, Sicklethorn)
This species has tiny white flowers that are fragrant, followed by brown berries. Uses curved thorns to climb structures, and can stretch to 40 feet, but in most gardens stays curbed at around 10 feet. Great for use as a foliage covering on walls or fences, or to provide shade for pergolas or trellises. Best in USDA zones 10-12. Considered invasive in tropical and subtropical regions, including Florida and Hawaii in the U.S. as well as Australia.

Asparagus officinalis (Asparagus, Garden Asparagus, Sparrowgrass)
These herbaceous, perennial plants reach between 3 and 5 feet tall, and can be grown as ornamentals or crop plants. Flowers are bell-shaped and greenish-white to yellowish, blooming in clusters of 1-3 in branchlet junctions. Toxic berries that follow are red. These plants are native to the western coasts of Europe. Foliage is green, and turns bright yellow in fall. There are many cultivars of this species, typically bred for hardiness and various crop colors. Best in USDA hardiness zones 3-10

Asparagus racemosus (Buttermilk Root, Climbing Asparagus, Water Root, Satavar, Shatavari, Shatamull, Shatawari, Yerrwuwu)
These plants are native to Australia, Africa and Asia, and reach between 3 and 7 feet tall. They grow well in gravelly soils, and have multiple uses, cultivated in many cultures for traditional medicine practices. Best in USDA hardiness zones 8-11.

Asparagus retrofractus (Asparagus macowanii) (Ming Asparagus Fern, Pom Pom Asparagus)
Erect and shrubby, this species is tender, with grey stems that grow 8-10 feet in length. Appears fluffy at first glance. Clusters of small white flowers bloom in spring. This is a great choice for a container plant and cuttings can be used as greenery in cut flower arrangements (they will last weeks in water). These plants are native to dry, western regions of South Africa. This species is considered invasive in certain regions.

Asparagus scandens (Basket Asparagus, Climbing Asparagus Fern, Krulkransie)
Vine-forming Ornamental Asparagus species that climbs to 6 feet tall or long. Leaves are deep green in color, and are held on drooping stems. Flowers are greenish-white and are followed by scarlet berries. Considered invasive in New Zealand and Australia.

Asparagus setaceus (Asparagus plumosus) (Asparagus Fern, Ferny Asparagus, Lace Fern, Asparagus Grass)
This species grows best in USDA hardiness zones 9-11 Sunset zones 12-24, H1 and H2. It is a branching vine that climbs by spines, reaching 10-20 feet long. Foliage is fern-like, and the plant produces tiny white flowers followed by purple-black berries. Forms a mass that is great for covering unsightly walls and fences. Foliage is used for filler in bouquets. Varieties include 'Nanus' (dwarf, good for containers), 'Pyramidalis' (with an upright habit, though is less vigorous than the species). Considered invasive in Australia, New Zealand, and tropical or subtropical regions of the United States.

Caring for Asparagus

Take care when planting these in the garden, as their berries are toxic to humans and pets, and some species are considered invasive in certain areas (namely Texas, Florida and Hawaii in the United States as well as New Zealand and Australia). Plant Ornamental Asparagus in a place in the landscape that is sheltered from drying winds and receives partial to full shade with indirect light; foliage will burn in direct sunlight. Ensure that soil is rich in nutrients, well-draining, and has a pH of between 6.5 and 6.8 (slightly acidic). If local soils are particularly poor in nutrients or do not drain well, make sure to amend the planting area with plenty of organic compost before installing. Apply a layer of mulch around the planting area to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention. At maturity, these plants appreciate consistently moist soils to thrive, and in dry areas will also need some additional humidity.

Fertilize yearly in springtime with an application of 2 inches of compost around the base of plants. Pull mulch back before applying, work the compost gently into the soil a bit, water it in, and then replace mulch. These plants are not heavy feeders, and this should be sufficient to provide the necessary nutrients for the active growing and flowering seasons. Pruning is simple; remove any damaged, diseased, or dead foliage at any time during the growing season, and remove spent flower spikes to neaten up the appearance of plants. If you desire the showy berries to form, make sure to leave some of the flowers on plants to develop. After these plants have been in the ground for a while, they may need to be divided if they are grown in a cramped space. For instructions on how to successfully divide an Asparagus Fern, see the Propagation section below. Asparagus plants are considered perennials, and can last in the landscape for 15-20 years or more if given proper care.

Growing Asparagus in Containers
Ornamental Asparagus are commonly grown in containers or hanging baskets, where their trailing green stems add interest and a spilling effect. Make sure to choose a container that has adequate drainage holes on the bottom to allow for excess water to flow away from the root zone. Fill with a well-draining but moisture retentive potting soil amended with organic material, perlite, and vermiculite. Top the soil with a layer of organic mulch to suppress weed growth, maintain consistent soil temperatures, and increase soil moisture retention. Place the plant in an area that receives partial shade (around 4-6 hours of sun each day is ideal with some sun protection during the warmest hours). Water new plantings regularly as they establish a strong root system in their new home. At maturity, these plants appreciate consistently moist soils but do not like to have soggy feet. As a general rule of thumb, water whenever the top inch of soil feels dry to the touch. Prune to remove dead, damaged, or diseased foliage at any time during the growing season. Asparagus grown in containers will need to be divided and repotted every so often to ensure ongoing plant health. For instructions on how to successfully divide Asparagus plants, see the Propagation section below.

Growing Asparagus Indoors
Asparagus Ferns are popular indoor houseplants, and can be grown in either containers or as members of terrariums or vivariums. Plant your fern in a container that is about an inch or two larger than its nursery pot size, and ensure that the container has adequate drainage holes in the bottom. Place the fern in an area that receives indirect light throughout the day. These plants do not like to sit in direct sunlight for too long; this exposure will sunburn leaves. They appreciate a well-draining, loose potting soil that can accommodate their root system. Potting these plants up every so often is critical; they form strong, clumping tuberous roots that can break a pot if they become too large. Alternatively, plants can be divided every so often instead of repotting. Divisions can be replanted in other containers or composted. For instructions on how to divide these plants, see the Propagation section below.

Harvesting Asparagus
Asparagus foliage is commonly included in bouquets and cut flower arrangements, typically harvested in spring or summertime after plants put on fresh new growth. The most commonly cultivated species for foliage harvesting include Asparagus asparagoides, Asparagus crispus, Asparagus retrofractus, and Asparagus seaceus. The best time of day to harvest foliage from these plants is in the late morning, after dew has dried but before the heat of the day sets in. Using sharp, clean shears, remove stems towards the base of the plant, cutting at an angle. Drop the stems into a bucket of cool water. When arranging, make sure to remove all foliage below the water line to extend vase life. Ornamental Asparagus foliage typically has a vase life of between 7 and 20 days.

Propagation

Asparagus, or Foxtail Fern, can be propagated by division or seed. To ensure that your propagated plant will have the exact same qualities and characteristics as the parent plant, use the division method. If you would like to experiment and see what plant you can grow from seed, just keep in mind that it will not necessarily be the same as the parent plant, especially if you are propagating a hybrid cultivar. To propagate your Foxtail Fern, follow the instructions below:

Propagating Asparagus by Seed

Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. The best potting medium for seed germination is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
Harvest your berries. They are typically present on plants in late summer and fall. Berries will only form on female plants after their flowers have been pollinated. They appear green at first, and mature to a bright red color. After they have attained their mature coloring, pick them from plants. Bring them indoors and either crush or cut berries to remove the dark brown to black seed inside. Rinse seeds to remove any remaining flesh and lay them out to dry. Seeds are best used fresh, but can also be stored in a dark, dry, cool area for upwards of 3 years.
Get your container prepared. Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination can take between 10 days and 8 weeks from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 65 and 72 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.

Propagating Asparagus by Division
This type of propagation is relatively simple; you will need a clean shovel, mulch, fresh soil, compost and pots (only necessary if you will be saving divided plants for transporting elsewhere). Division is best done in very early spring (after the plant has entered dormancy, but before it has begun its new spring growth). To propagate by division, follow these steps:

Using a shovel, dig up your existing plant. Start from the outside and work your way in to avoid damaging the root(s). Once you have worked it up out of the ground, lay it out.
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 root section attached.
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 divisions and water thoroughly.
Apply a thick layer of mulch over the new planting to protect it from cold weather as it acclimates to its new home. Then, enjoy watching it sprout in the next growing season.