Cytisus

cytisus

( SIT - iss - us )

At-A-Glance Information

Commonly called Broom, this group of evergreen, semi-evergreen and deciduous perennial shrubs requires full sun and little to no water, making it a great candidate for a water-wise California garden. This is the most popular of the Broom species; its flowers are commonly quite fragrant, and these plants can tolerate windy conditions and seaside climates with ease. Use these flowering shrubs in mixed beds and borders, in containers, along walkways, or in open areas of the landscape. Take care when planting these flowers in the landscape, as plant parts can be toxic to humans and pets if ingested.

cytisus Species and Varietals

The genus Cytisus includes around 27 species and is a member of the family Fabaceae. Cytisus growing zones vary by species; see the descriptions below for more information. To find your zone, click here: Zone Map.

Cytisus battandieri (Atlas Broom, Pineapple Broom, Moroccan Broom, Pineapple Tree)
These shrubs can be semi-evergreen or deciduous, and grow best in USDA hardiness zones 7a-10b or Sunset growing zones 4-6 and 14-17. They are native to Morocco and grow quickly to 12-15 feet tall and just as wide. Shrubs be trained or pruned into small trees. Pure yellow, fragrant flowers form in clusters at the ends of branches in the summertime.

Cytisus multiflorus (White Broom, White Spanishbroom, Portuguese Broom)
These shrubs reach up to 3 feet tall when mature, and have a sprawling habit. These plants are native to Portugal and Spain. Flowers are white and bloom along branches in spring and summertime. White Broom grows best in USDA hardiness zones 6-10. This species is considered invasive in California, regions of Australia, New Zealand, and areas in Europe.

Cytisus nigricans (Lembotropis nigricans) (Black Broom, Shrub Broom)
This species of Broom reaches between 3 and 5 feet tall when mature, and produces yellow flowers that are slightly fragrant in summer and autumn. Cultivar 'Cyni' is compact, reaching just a little over three feet tall. These are hardy plants, but do prefer some shelter from full sun, especially during the hottest hours of the day. This species grows well in USDA zones 3-9.

Cytisus x praecox (Warminster Broom, False Heather)
Deciduous species, grows best in USDA hardiness zones 5-9 or Sunset growing zones 2-9 and 14-22. Plants have a compact growth to 3-5 feet tall and 4-6 feet wide with many stems. The species forms a mound of creamy white flowers in springtime. Can be used as an informal screen or hedge along driveways or pathways. Varieties include 'Allgold' (a slightly taller mound, with bright yellow flowers), and 'Hollandia' (with pink flowers). This hybrid is considered invasive in several regions, including North America (Pacific Northwest, California, and areas along the East Coast), New Zealand, Australia, and India.

Cytisus scoparius (Scotch Broom, Common Broom, English Broom, Scottish Broom, Broomtops)
An evergreen species that grows best in USDA hardiness zones 5-8 or Sunset growing zones 2-9, 14-22 and H1. This is a European species that is considered invasive, has an upright habit, with golden yellow flowers in spring and early summer. This species is considered invasive in western North America (California, Oregon, Washington, and British Colombia), Australia, New Zealand, and areas of South America.

'Burkwoodii'
Has red blooms with a touch of yellow.

'Dorothy Walpole'
Has rose-pink flowers marked with crimson.

'Lena'
Red and yellow flowers.

'Lilac Time'
Lilac blooms on a compact plant.

'Pomona'
Orange and apricot-colored flowers.

'Stanford'
Red blooms.

Caring for Cytisus

Plant Cytisus shrubs in a space in the landscape that receives full sun; ideally, they appreciate between 6 and 8 hours of sun each day for the best blooms. When these shrubs are grown in less light, they will not flower as profusely and have a tendency to become leggy. Ensure that soil is well-draining, rich in nutrients, and has a pH of between 5.0 and 6.5 (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. Water new plantings regularly as they establish a strong root system in their new home. At maturity, these plants are considered drought-tolerant, able to get by on rainwater alone for much of the year with supplemental irrigation during extended periods of warm weather.

Fertilize yearly in early 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. 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 and encourage reblooms. Shrubs can be reshaped (renovated) in early springtime if a bushier habit is desired. Cytisus plants are considered very easy to care for and are able to thrive in neglect. Cytisus shrubs are perennial, and can be expected to survive for between 10 and 20 years or more in the landscape before needing to be replaced.

Propagation

Cytisus can be propagated either by using cuttings or from seed. To ensure that your propagated plant will have the exact same qualities and characteristics as the parent plant, use the cutting 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. To propagate your Broom, follow the instructions below:

Propagating Cytisus by Cutting

Gather your materials. You'll need a clean, sanitized, sharp pair of garden shears, rooting hormone, a pencil, and a 3-inch pot filled with well-draining compost or other organic material. A good substrate for propagation of cuttings 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.
In spring or early summertime, choose the plant that you'd like to propagate. Ensure that this plant has had a good watering the night before, as this will improve the chances your cutting will take root. Cut one or more 6 inch portion(s) of the end of a non-blooming branch and strip the leaves off of the lower half. Make a hole in your planting medium by pushing your pencil into the soil. Dip the end of the stem in rooting hormone, and plant it in your pot. Fill in soil around the cutting to support it, but do not pack it down too much.
Moisten with water, and ensure that the pot has good drainage. Your pot should be kept in warm, sunny conditions indoors (and not in direct sunlight). Water whenever your soil is dry under the top layer. After about four to six weeks have passed, your cutting should be rooted. When you notice new growth on your propagated shrub, you'll know you have roots.
Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring, when you can transplant it to its new home. Ensure that the last frost of the year has occurred before doing this, as it can seriously damage your new shrub.

Propagating Cytisus 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 seeds. The seed pods on Cytisus plants are pretty easy to spot, they're large and dangle from the branches, left behind after flowers have faded. Once they have dried out and begun to split open, you can harvest the seeds inside. Cut them off of the plant, placing them in a paper bag. Harvest as many as you can, and place the paper bag in a dry, cool, dark area. They will begin to split open and release the seeds contained inside. Once they have been released, take them out of the bag and put them in a container so you can work with them.
Soak your harvested seeds in lukewarm water for 24 hours, then take them out and lay them out to dry.
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 with your spray bottle. 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 usually takes around 4 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 55 and 70 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.

Cytisus seed pods, dried on the plant and ready to be harvested.

Cytisus seeds are small, tan to brown, and rounded at one end.

Problems and Pests

Many species of Cytisus are considered invasive in certain regions of the world. See the species descriptions above for more information, and check with local authorities before purchasing or planting. Cytisus shrubs can develop problems with the following pests and diseases: