How to Plant and Grow Rue

At first glance, you might think that the rue plant is just an ordinary blue-green leaved bushy herb with its flowers waving above the foliage, but you’ll soon discover that it has some distinguishing characteristics worth noting. Cultivated since the 16th century, rue is one of the oldest garden plants and is known for its bluish leaves and tolerance of dry soil conditions.

When rue's tough, fleshy leaves are lightly disturbed, it gives off a fruity smell. Be aware that when the plant is crushed, it emits a powerful musk odor. So, what is there to love about rue? Surprisingly, the rue plant is a natural choice to add to a butterfly garden because, in addition to being beautiful, it is a host plant for the black swallowtail, giant swallowtail, and other butterflies.

Where to Plant Rue

Rue’s finely cut blue-green foliage makes it a very attractive clumping plant when planted in rock gardens with full-to-part sun conditions. Rue self-seeds, so be sure to remove its flower heads before they set seed to avoid unwanted plants growing in your garden. Rue often grows wild in vineyards and gravel pits on rough, stony ground.

How and When to Plant Rue

Plant rue seeds outdoors in the spring so it has the entire growing season for the roots to grow. The seeds should be barely covered with soil when planted. It’s important to be patient with the germination process because it can take up to 4 weeks for rue seeds to germinate. Once the seedlings emerge, be sure to thin or transplant them to allow one foot of space between plants.

Rue Care Tips

Rue is so easy to grow that it can easily become a nuisance in the garden with its ability to self-seed.

Light

Rue grows best in full sun and should receive at least six hours of direct sunlight daily. The plant also tolerates part shade, however, it will produce fewer flowers in the shade.

Soil and Water

Rue grows best in moderately fertile, well-drained soil, but will tolerate dry and rocky soil. Rue tolerates drought, so like other drought-tolerant perennials, you’ll only need to water the plant when dry weather lingers.

Temperature and Humidity

Rue is extremely drought-tolerant and thrives in loose, lime-containing soil in a sheltered area. The rue plant is tolerant of humidity as long as its soil has good drainage.

Fertilizer

Rue generally does not require fertilizer if it is planted in rich soil. If your soil is poor, add a completed balanced slow-release fertilizer once each spring, following product label instructions.

Pruning

In early spring, prune stems back to 6 to 8 inches to encourage bushier growth and to keep the rue plant from getting too leggy.

Pests and Problems

Rue is seldom affected by insects or diseases. It is a hardy plant that is deer-resistant and attracts pollinators. Root rot may occur if rue is overwatered or planted in poorly drained soils. 

How to Propagate Rue

The rue plant is usually propagated by seed and germinates after a cold period. You can also take stem cuttings from established plants and root them in a shady place or container and then transplant them.

Types of Rue

'Jackman's Blue' Rue

Ruta graveolens ‘Jackman's Blue’ is noted for its vivid blue foliage. Like common rue, it bears yellow flowers throughout the summer. It grows 2–3 feet tall and wide. Zones 4–10

Fringed Rue

Ruta chalepensis L., commonly known as fringed rue, is named for its fringed yellow flowers, which appear in spring on plants with blue-green foliage that closely resembles that of common rue. It’s also known as Egyptian rue. This rue plant is a favorite larva plant of swallowtail butterflies. It grows 2-3 feet tall and 2 feet wide. Zones 8-10

Rue Companion Plants

Rue doesn’t coexist with many other plants well because it can poison the soil around its roots with the chemicals it exudes. Do not grow rue around basil, sage, cabbage, cucumbers, and mint. However, companion planting rue with the following plants can be beneficial.

Onions

Growing onions, a staple ingredient for flavoring many recipes, with rue can prevent onionfly larval damage. Rue’s scent deters the onionfly from laying its eggs near the vegetable. Onions can be grown from seed or they can be started from sets or bulbs for a jump start on the growing season. To sow onion seeds outdoors, plant them ¾ inch deep in loose, moist soil. In the garden after seedlings emerge, thin them to 3–4 inches apart in the garden. Plant onion bulbs or sets in the garden two to three weeks before the average last frost date.

Roses

Planting rue next to roses, one of the most popular flowers in the world, will help deter aphids from your rose garden. Roses should be planted after the last frost in the spring or in fall (at least six weeks before your average first frost). Dig a hole big and wide enough to fit the entire root system—roses don't like to be crowded. Also, plant rose bushes at least 3 feet apart to allow for growth.

Raspberries

Growing rue next to raspberry plants will help keep damaging insects such as aphids and beetles away from your raspberries. Plant raspberry canes 20 inches apart and in rows 5 feet apart. Raspberry plants are hardy in USDA Zones 3-9, so once they’re established, you don’t have to worry about replanting them each year.