Plant care & info

Family: Olaeceae

Genus: Syringa, from the Greek syrix, a reed or pipe, referring to hollow stems.

Common Name: Lilac Origin: Eastern Asia & SE Europe

Many species of deciduous shrubs or small trees with panicles (upright clusters) of small, spring-blooming flowers, all of which are fragrant. A broad selection of flower colors exists, from white to pink to purple. Leaves are opposite, simple or pinnate. Fruit is a 2 valve capsule.

Lilacs prefer full sun, at least 6 hours daily. They perform best in neutral to alkaline pH, so adding lime to acidic Portland soil is important. Adding mulch (a layer of organic matter like bark chips) after planting, and yearly thereafter will help soil drainage improve.

Lilacs need one inch of water per week, and they do not appreciate over watering. Once established, water needs will decrease, but they like a deep drink in the heat of summer.

Prune spent flowers immediately after bloom has faded. To renovate, prune 1/3 of the oldest wood to 12-24″ from ground level.

Bacterial and fungal problems are the arch enemies of Lilacs in Portland. In the “Manual of Woody Landscape Plants” Michael Dirr lists bacterial blight, Phytophthora blight, leaf blights, leaf spots, powdery mildew, wilt, ring spot virus and witches’ broom as potential problems. Not to mention bugs. Yikes!

The best bet for avoiding problems is to improve soil drainage, as suggested above, keep the area around the plant clean by raking leaves in autumn and pulling weeds, fertilize regularly, add a layer of mulch over the roots in spring and fall, and apply preventative dormant sprays.

And pray for sunshine. If problems develop despite your best efforts, there is a slew of fungicides that can help.

Who cares if it gets water and pollen all over your face? The scent is so worth it!

Lilacs are one of those old fashioned favorites that remind us of our Grandmothers who loved them just as much as we do. Everyone should have at least one.

When the word “Lilac” is mentioned, most folks will think of Syringa vulgaris cultivars, or French Hybrid Lilacs. They are indeed some of the most popular, offering somewhere over 400 different cultivated varieties, in colors ranging from white to blue to purple, and even yellow.

There are however, several additional species of Lilac that are very worth noting and growing. Below we offer information about some of our favorites.

Explore More Lilacs

Cut Leaf Lilac

Syringa Laciniata: Cut Leaf Lilac

Small single lavender flowers with great fragrance bloom in May. Fine-textured bright green feathery leaves add interest. It is perhaps the only lilac that can bloom reliably in partial shade, and it can stand up to hot humid conditions too. Add resistance to powdery mildew, and you have the perfect lilac.

Grows 6-8′ X 6-8′, Sun-part shade, Zone 4.

Dwarf Korean Lilac

Syringa Meyeri ‘Palibin’: Dwarf Korean Lilac

Reddish buds open to pale pink flowers borne on 4″ clusters in May. Blooms prolifically and at a young age. Fragrance is nice, but not the typical “Lilac” perfume. Small round leaves are green and edged with purple when new, turning completely green with age. The overall shape is dense and round.

Grows 4-5′ tall x 5-7′ wide, Sun, Zone 3.

Manchurian Lilac

Syringa Patula ‘Miss Kim’: Manchurian Lilac

Purple buds open to fragrant, single lavender flowers in May. Blooms prolifically and reliably at a young age. Leaves are long and pointed. ‘Miss Kim’ is one of the only Lilacs to develop nice fall color – reddish-purple.

Grows 6′ x 6′, Sun, Zone 4.

Preston Hybrids or Late Lilacs

Syringa Prestoniae: Preston Hybrids or Late Lilacs

Developed by Isabella Preston in the 1920’s, Preston Hybrid Lilacs bloom 2-3 weeks later than most other Lilacs, extending the bloom season for Lilac fans. Flowers occur on the current season’s new growth, and are mostly single form flowers in shades of pink, with a scent that’s a bit more wild than typical lilacs. Leaves are typically healthy and lime-green on stout branches. Preston hybrids have excellent overall vigor, and nice bushy habits.

Grows 8-10′ tall and wide, Sun, Zone 3.

Japanese Tree Lilac

Syringa Reticulata: Japanese Tree Lilac

White flowers emanate a lovely scent that wafts through the warm air of early summer. This June-blooming lilac has green leaves and grows in an upright tree shape. The variety ‘Ivory Silk’ is the most common and it is a really great small tree for small yards. Japanese Tree Lilacs need occasional summer watering even after they’re established, and even though they bloom best in sun, they don’t like sites that are too hot and dry.

Mature at 20-30′ tall and 15-25′ wide with an oval to round crown, Sun, Zone 3.

French Hybrid Lilacs

Syringa Vulgaris: French Hybrid Lilacs

These are your Grandmother’s Lilacs. Heavenly scents, a broad range of colors and single or double flower forms are some of the benefits of French Hybrids. Among their difficulties are increased susceptibility to disease, rangy habits, and foliage that shows its age by the end of summer.

To love this plant, you have to be all about the flowers. Flowers are grouped into color classes: Violet, Blue, Purple, Magenta, Lilac, Pink, White and Yellow. They can be single form, having only 4 petals, and double, or clustered, having 8 or more. Bloom is usually in late April and early May in Portland.