Water Wise Plants

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Yarrow ‘Moonshine’

Perennial

2 ft.

Low: water every three weeks until the root ball is wet

Full sun

Bright yellow

Achillea ‘Moonshine’ is a reliable mid-summer bloomer whose deep yellow flowers will stand out in a garden. Requiring very little maintenance, these plants are a magnet for butterflies and beneficial insects. The flowers have lots of nectar and the flat shape of the flower serves as a perfect landing pad for butterflies. Deadhead spent flowers to keep the plants looking fresh. Vigorous clumps can be divided in the winter.

ah-KILL-lee-ah tay-GET-ee-uh

Yarrow ‘Taygetea’

Perennial

12 in. to 18 in. wide and tall

Low: water every three weeks until the root ball is wet

Full sun

Creamy yellow

‘Taygetea’ Greek yarrow is a cheerful, reliable summer bloomer. The flowers start out bright yellow in midsummer and fade to a more mellow shade over time. The grey-green foliage blends in well with many plants found in low water gardens. This cultivar of yarrow seems to be more drought tolerant than the popular Achillea millifolium. 

Greek yarrow doesn't need a great deal of maintenance. To encourage reblooming, deadhead it regularly. This plant will spread, so don't plant it too tightly.

kar-pen-TIER-ree-uh kal-ih-FOR-nik-uh

Bush Anemone

Shrub

6 ft. tall and 4 ft. wide or possibly larger

Low: water every three weeks until the root ball is wet

Full to half sun

White

Carpenteria is an evergreen shrub and works well as a background shrub or in mixed plantings under oaks. This shrub has pretty leaves and cheery ‘egg over easy’ flowers. It is a UC Davis Arboretum All-Star and a California native.

Carpenteria californica is a flexible plant, tolerating light to moderate water and full sun to partial shade. One drawback of this plant is the brown leaves don’t always drop off in summer. If this shrub is in a very visible spot, it may be desirable to cut off the brown leaves for a cleaner appearance.

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California Wild Lilac

Plant type depends on cultivar

Many different types

None: avoid summer water

Full to half sun

Purple, dark blue, medium blue, white

Ceanothus is a California native evergreen shrub. It is very showy in late winter and early spring when it covers itself with beautiful blossoms. Most Ceanothus have blue blooms that are very attractive to bees and other insects.

There are many different kinds of Ceanothus. Some are low growing ground covers; some are shrubs, and some become tree-like. Most Ceanothus need to be planted in a dry part of the garden because they are very sensitive to summer watering. Ceanothus varieties originally from the coast, such as ‘Carmel Creeper’, are more tolerant of summer water. Cultivars should be researched carefully to select the right plant that meets individual garden conditions. 

It is best to prune Ceanothus in the late summer when they are dormant. Take care not to cut into large branches. Only prune branches that are an inch or less in size.

Even with proper pruning and watering, these plants can be short-lived (five to ten years), but their beautiful spring flowers more than make up for any challenges.

KOR-ree-uh AL-ba

Australian Fuchsia, White

Shrub

8 ft. high and wide

Low: water every three weeks until the root ball is wet

Full to half sun, shade

Correa alba looks very different from the more commonly grown Correa ‘Dusky Bells’. The flowers are more open and less downward facing than other Correas. The foliage is fuzzy on the back side and the stems are bronzy brown. This shrub can grow to 8 feet by 8 feet without regular pruning.

Like Correa ‘Dusky Bells’, Correa alba thrives in sun, partial sun, or shade; is deer resistant and bird friendly; and has long-lasting flowers. The plant does well with moderate to occasional water, tolerates alkaline soil, and is evergreen. The plant is sensitive to overwatering and overfertilizing.

PADG notes: Some find Correas to be short-lived but at the Palo Alto Demonstration Garden, this plant is still going strong after several years in the garden. The beds in garden are mulched with wood chips, but not fertilized and watered deeply with drip irrigation once every three weeks.

esh-SHOLZ-ee-ah cal-ih-FOR-nih-kah

California Poppy

Perennial

6 in. wide and 6 in. to 12 in. tall

Low: water every three weeks until the root ball is wet

Full sun

Bright orange, golden, pale yellow, red, cream, rose

California poppies look great in wild areas and are lovely massed. They make excellent temporary fillers in new beds and landscapes. 

California poppies can get by with almost no summer water, but they tend to look shabby and weedy under these conditions. To encourage continuous bloom, provide moderate amounts of water and trim the plants back to almost ground level when the foliage turns grey, and the plants lose their flowers.

Although California poppies are perennials in the Santa Clara Valley, they can be treated as annuals. California poppies can be problematic because they are aggressive reseeders. They should be heavily thinned even in desired areas and removed entirely when undesired. They can reach one and a half feet wide in size and can smother other plants.

Most retail nurseries and many hardware stores sell seeds for California poppies. Some mail order companies are good sources for some of the less common varieties of these California natives. Plant seeds in the fall for a spring show. Be sure to cover seeds with mulch to hide them from the birds and water regularly until they sprout if the winter rains have not arrived.

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Spanish Lavender

Shrub

1 ft. to 2 ft. tall and 2 ft. to 3 ft. wide

Low: water every three weeks until the root ball is wet

Full sun

Purple

Lavenders are a favorite plant for low-water gardens with their aromatic foliage and showy spikes of scented flowers. Full sun and good drainage are essential for lavenders. Shear the plant after blooming to maintain a neat appearance and discourage the plant from becoming too large and woody. Lavender is a short-lived shrub that may need to be replaced when it becomes leggy or woody after about six years.

Lavandula stoechas is an early bloomer and will repeat bloom if deadheaded and given supplemental water.

PADG notes:  Several different types of lavenders are planted in the Demonstration Garden, including ‘Otto Quast’, a successful cultivar which is also a UC Davis Arboretum All-Star plant.

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Rose 'Happenstance'

Perennial

3 ft. tall and wide with regular pruning

Low: water every three weeks until the root ball is wet

Full sun

Light yellow to white

Roses have a reputation for being lovely shrubs that require a lot of maintenance and water. 'Happenstance' rose is a beautiful, disease-free shrub rose that does fine on a low water diet.

The pale-yellow flowers of 'Happenstance' provide a calming contrast to more brightly colored flowers. The arching branches of 'Happenstance' rose form a neat mound.

PADG Notes: This rose is a slow grower in the garden and doesn't need a lot of deadheading or pruning because it is not highly fertilized or watered. In February, some of the longer canes of 'Happenstance' are pruned back to about two feet to keep the rose a three-foot mounding shrub over the summer.

Despite the low maintenance approach, this plant blooms continually in the spring, summer, and fall. It is highly recommended as a medium-sized rose for water-wise perennial gardens.

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Butterfly Rose

Shrub

8 ft. to 10 ft. tall and wide

Low: water every three weeks until the root ball is wet

Full to half sun

While most hybrid tea roses like regular water and fertilizer, there are many antique roses that withstand tough conditions. Rosa x ordorata 'Mutabilis' is very successful under a low water/no fertilizer regime. This rose prefers full sun but will grow and bloom in part shade.

Rosa 'Mutabilis' grows into a large shrub with delicate blossoms that open orange, then turn pink and finally maroon as it ages. The bronzy colored new foliage is also attractive. Blooming all summer, it is a focal point in the garden.

PADG Notes: This rose is pruned back to about four feet in February, selectively cutting smaller branches back to a main stem. This helps keep the plant a manageable size and encourages lots of blooms over the summer.

TAN-uh-SEE-tum DEN-sum AHM-an-eye

Partridge Feather

Groundcover

6 - 8 in. high, spreading slowly to make a mat about 1 1/2 ft. wide

Moderate: water weekly until the root ball is wet

Full to half sun

Yellow

Tanacetum densum amani is a ground cover that is native to Turkey. Its leaves are silver and have a feathery texture.

PADG Notes: This plant is used as an edger in one of our beds. One drawback to the plant is the small yellow flowers that appear in late spring. Some people like them, but we cut them off.

This plant has survived, but not thrived at in the Palo Alto Demonstration Garden. One reason might be that it likes more water than it receives. It is watered deeply every three weeks. We suspect this plant would look lusher in the summer with deep weekly watering.

This plant is not easy to find in nurseries and gardens, but if you like the texture, Tanacetum densum amani is worth seeking out.

TY-mus vul-GAR-iss

Thyme

Groundcover

3 in. high and 3 ft. wide

Low: water every three weeks until the root ball is wet

Full to half sun

Many herbs, including thyme, are great additions to water wise gardens. They can be used in cooking; they smell great and their foliage and flowers are attractive.

Thyme makes a nice ground cover for small spaces. It has grey-green leaves and small white flowers.

PADG Notes: To keep thyme neat, the faded flowers are sheared back in early spring. Many thymes are not long lived, but Thymus vulgaris has proven to be long-lived in our water wise garden.