Learn all the tips on how to grow and care for lilac bushes here!
Lilac shrubs burst with colorful blooms in mid to early spring. They bring romantic flower blooms and enticing fragrance to the spring garden. Famous for their vibrant purple flower buds and romantic scent, lilac plants are also incredibly easy to grow!
Lilac bushes need ample sunlight, fertile soil with good drainage, and a little bit of pruning. Learn everything you need to know to plant, grow and care for lilac shrubs right here!
How To Grow Lilacs (In Short)
Lilac bushes are easy to grow but they do have a few basic requirements that must be met.
These vibrant bloomers prefer slightly alkaline soil that is well draining. Lilac bushes also need a high quality soil full of organic matter, especially when they are young!
Lilacs must have 6 to 8 hours of sun in order to thrive. Young lilac bushes need regular watering, while older lilacs are moderately drought tolerant.
Lilac flowers bloom on old wood and need to be pruned in late spring after the buds have just faded.
The best time to plant lilac bushes is in early spring as soon as the ground is workable (and there is no sign of frost.). They can also be planted in early to mid fall before the first frost set in.
Keep reading to learn more details on the right soil, sunlight and watering methods for lilac flowers.
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Benefits Of Growing Lilacs:
Lilac bushes have an intoxicating fragrance and unfurl romantic, aromatic blooms each spring. Here is why you’ll love growing them:
- Lilacs are easy to grow once established and require little in the way of fertilizer and upkeep
- The spring flowers attract hummingbirds and butterflies with their lovely fragrance and pretty colors
- Lilac flowers are edible and can be used in a variety of herbal teas, treats and tinctures!
- Lilac foliage stays green and beautiful all season long (until first frost)
- These romantic flowers are perfect in a cottage garden or English garden
- As a deciduous shrub, your lilac flower will come back year after year!
- Lilacs come in many sizes: dwarf lilacs are perfect for small gardens
About Lilac Bushes
Lilac bushes, also known by their Latin name, Syringa vulgaris, are beautiful perennial flowering bushes. They originate from Eastern Europe on the Balkan peninsula and in their native habitat grow on rocky terrain full of sunshine.
Lilacs are known to be reliable, hardy growers that can live for decades.
They are famous for their fragrant blooms and beautiful green foliage. They light up spring with their deep floral aroma and bold hues of purple (and other colors!).
Lilac bushes have been widely cultivated and were introduced to the United States in the late 1800’s.
The four petaled, cross shaped flowers have a tubular shape that attracts hummingbirds, bees and butterflies. Flowers are available in various shades of pink, purple, mauve and white.
The most popular hue for lilacs is bold purple. Individual flowers unfurl along a long pinnacle. The leaves are light green and oval in shape and stay vibrant until late fall to early winter.
These elegant shrubs need cold winters in order to thrive and grow best in zones 3-9. Special varieties are available that can grow in warmer climates.
Depending on the variety, lilac shrubs can grow to be quite tall: up to twenty feet and 10 feet wide. (There are dwarf varieties that hang out in the 5 ft tall range).
When in full bloom lilacs overflow the senses with their elegant beauty and aromatic flowers.
When Do Lilac Flowers Bloom?
Lilac flowers bloom in spring! Lilac bushes bloom in the spring time: the months of April, May and early June.
Bloom time depends on what type of lilac variety is grown and the local growing zone. The current seasonal weather conditions will also affect bloom time.
In the last few years we have had wild spring weather in the Northwest. The temperatures have stayed colder longer, and there has not been as much sunlight and warm temperatures. This has delayed our typical bloom time for lilacs by 2-3 weeks. The weather greatly impacts the bloom time of spring plants such as lilacs.
You can increase the amount of time that your lilac bush booms for by planting different varieties of lilacs that bloom at different times in the season. This will ensure you have a long show of beautiful lilac flowers!
How Long Do Lilac Blooms Last?
Lilac blooms typically last about two weeks, depending on the variety of lilac and the weather conditions.
While a lilac flower’s scent is romantic and intoxicating, they do not, unfortunately, last very long. Rain can affect how long the lilac bloom thrives. The best way to ensure a long blooming season is to plant different varieties of lilac trees that bloom at various times throughout the season.
Different Lilac Varieties
There are over 25 different lilac varieties and thousands of unique cultivars.
Common Lilac, Persian lilac, and Dwarf Korean lilacs are three common varieties.
Common lilac bushes (also known as French lilac) are easily grown and typically found in areas with moderate temperatures. They feature bold colored flower blooms in bright purple, pink, white and even yellow.
Persian lilacs have an elegant arch and feature pale violet flowers that have a heady fragrance.
Dwarf lilacs are compact and dense, saving space in the yard but making a big impact with fragrant blooms and bold flower color. Dwarf Korean lilac are especially popular!
We have been lucky enough to visit the Hulda Klager Lilac Festival for years. Here are a few beautiful lavender varieties with photos from the gardens and notes on each variety:
Maiden’s blush is an early blooming upright lilac variety that feature beautiful soft pink flowers. This lilac bush is known for abundant flowers and blooms open 7-10 days before other varieties.
Resplendent in beautiful white flowers, Carley is a mid season bloomer that can’t be missed. The single blooms have a star shaped flower petal that look gorgeous as cut flowers.
Lady Lucille is a gorgeous vibrant purple lilac with bold purple blooms. She flowers in mid season and can grow to be 10-12 ft tall.
The Best Place To Plant Lilacs
Lilac bushes need to be planted in an area that has direct sunlight and enough space for the plant to grow. Choose a location with good soil drainage and rich, fertile soil.
The first year of growth helps the young plant establish and begin to grow a healthy root zone, so be sure to pick a good location that features adequate soil drainage, full sun and humus rich soil.
Avoid planting lilac shrubs in windy areas.
When To Plant Lilac Bushes
The best time of year to plant lilacs is either in early spring or mid fall. Do not plant lilac bushes in mid to late summer as the heat can be detrimental to a new, small tree.
Plant lilac bushes in early spring before the buds on the plant start to unfurl. A lilac bush can also be planted in mid fall before the ground freezes.
How To Plant Lilac Bushes
Planting lilac bushes is pretty simple. You will need a shovel, soil amendments as needed, and your lilac plant. We recommend using bone meal as it nourishes the plant’s roots and is slightly alkaline.
To plant a lilac bush follow these steps:
- Dig a planting hole large enough for the root ball to sit in, but allow the base of the plant to be at ground level with the soil
- Add a handful of bone meal to the soil and blend well
- Remove the lilac from it’s container and score the roots
- Back fill the hole with soil and compost if needed
- Give the plant a nice long drink of water!
Lilac Bush Plant Needs
Lilac bushes have specific sunlight, water and soil needs. Be sure to read these guidelines before planting your lilac bushes:
Lilacs need 6-8 hours of full sun. They thrive off of sunlight and will not bloom if not given enough light! While lilacs will tolerate part shade, they will not produce as many blooms without full sun. Late afternoon shade can work for lilacs if they have enough morning sun.
For best results give your fragrant flowers a sunny spot with at least 6 hours of sunlight per day!
Lilac bushes need well drained, fertile soil with a pH of 6.5-7 in order to thrive. Lilacs do not like their roots to be wet and need good drainage.
Amend heavy clay soils with organic matter in the form of compost, decaying leaf matter and rotted farm manure.
According to the Hulda Klager Lilac Society, good soil drainage is absolutely essential for lilacs. In fact, if the lilac is planted in standing water the plant will decay and die. In heavy clay soil a mound can be built out of soil and compost in order to encourage good draining.
Lilac roots grow to be very long! The root system spreads widely and the root zone can grow to be as long as the plant is high (about 10-15 feet in diameter). Though a lilac’s roots are not invasive, they do have aggressive root growth.
pH Level For Lilac Bushes
Lilac bushes are fussy about pH levels. They prefer the soil to be neutral to slightly alkaline.
Since lilacs prefer slightly alkaline soils, be sure to test your soil with a pH meter before planting. This can be easily done with a simple pH test kit. If you find your soil is too acidic, you can amend it with lime. Get a quality soil test kit here.
If the soil tends to be overly alkaline, you can bring it back into the ideal range by adding aluminum sulfate to the soil.
Lilacs prefer humus-rich soil that is well draining and slightly alkaline. (Humus refers to any decaying plant matter within the soil). Soil is one of the most important factors in growing lilac bushes, so be sure to take time to amend and improve your soil prior to planting your lilac flowers.
*In general, it is not advised to use peat moss to amend acidic soils when planting lilac. This is because peat moss tends to absorb water.
Established lilacs prefer to have a long deep drink of water infrequently. They cannot stand having wet roots and over watering can encourage disease and limit the plant’s blooms. Well-drained soil is a must!
Lilac bushes need different amounts of water based on the age of the plant and whether or not it is grown in a container:
- Newly planted lilacs: Young lilac plants need to be watered regularly so they can establish their roots. Check the soil daily and when the top inch of the soil is dry, give the plant a long drink. (You can stick your finger into the soil up to the first knuckle. When the soil begins to dry out, water!).
- Established lilac bushes: Established lilacs prefer a long, deep drink about every two weeks during hot weather and drought like conditions.
- Potted lilac plants: A potted lilac will need to be watered more frequently than a lilac in the ground. Check the soil moisture in the container regularly, especially during hot weather. In warmer climates check the potted plant every few days and when the soil is dry make sure to water the plant.
*Bone meal can be purchased at your local garden center, or you can order it on Amazon here.
When given the right soil conditions lilac bushes do not need a lot of fertilizer and are not heavy feeders.
If the gardener desires, lilacs can benefit from a mild, balanced fertilizer in early spring before the growing season begins. Do not over fertilize!
Use a fertilizer with a balanced NPK ratio. (The NPK ration refers to the Nitrogen, Potassium and Phosphorous available in the fertilizer formula).
Apply the fertilizer around the plant’s drip line in early spring. (The drip line is the area underneath the circumference of the outer most branches).
The right time to fertilize lilacs is in early spring when the shrub is just beginning to sprout it’s green leaves.
Providing good air circulation for lilac bushes will help prevent disease and give the plant adequate room to grow.
Lilacs can grow to be large shrubs, so keep that in mind when planning your garden beds and planting lilac.
Space large lilacs at least 4 feet apart from each other. In ideal circumstances a lilac bush will have a 10×10 square foot radius in which to grow.
If you have a small space, consider planting dwarf lilac varieties.
Quality air circulation can be achieved by preventing plants and weeds from growing up and around the lilac and suffocating it. You also need to plant your lilac shrub with enough spacing so that it does not become overgrown by another tree or shrub.
Good air circulation will prevent rot, decay and fungus like powdery mildew from forming.
Where To Buy Lilacs
Lilac bushes can typically be purchased at a local nursery or garden center. You can also find them at specialized lilac gardens and growers, such as the Hulda Klager Lilac Gardens.
Should Lilacs Be Deadheaded?
Most lilac varieties do not need to be deadheaded. They will not produce additional flowers if you remove spent blooms. That being said, removing spent blooms allows the plant to put it’s remaining energy into creating flower buds for the next season.
So while deadheading will not increase the amount of blooms produced, it will direct the plant’s resources to creating more beautiful flowers for the following year.
To deadhead lilacs: As soon as the flowers are done blooming, simply snip the spent blooms off.
Remember that new lilac flowers grow on old wood. So use care when pruning to avoid cutting off the new growth!
How + When To Prune Lilacs
Annual pruning can prevent lilacs from becoming unruly and growing out of control. Lilacs bloom on old wood, however, so pruning needs to be done right after the plant blooms.
The ideal time to prune lilacs is immediately after the lilac bush is done blooming in the spring.
Next year’s flowers will soon be forming on the old wood so timing is important. Prune any diseased or unproductive limbs and dead wood, and remove the oldest branches that are not producing lilac flowers. This article is a wonderful in depth article on how to prune lilac bushes at all stages of their growth.
Fungal Disease, Insects + Pests
Bacterial blight is a disease that affects the leaves of a lilac tree. Leaves will begin to show dark color and water soaked spots that eventually morph together and kill the leaf.
At the first sign of bacterial blight, remove the affected leaves and burn them. A copper based fungicide during early spring can also be effective. Learn more about lilacs and bacterial blight here.
Powdery mildew can also be a problem for lilac bushes. The leaves may become covered with tiny microscopic fungi that appear white. While powder mildew typically occurs at the end of the season and does not harm the plant, it can be unsightly.
To combat powdery mildew on lilacs, give your lilac great growing conditions with plenty of air circulation, water at the base of the plant, and make sure you are not over fertilizing.
FAQ’S On How To Grow Lilac Bushes
The best spot to plant a lilac bush is in full sun that has well draining soil and is sheltered from wind. Give your plant plenty of space to promote good air circulation.
Yes, lilac bushes are very easy and fun to grow. As young plants give them the right soil that is humus rich and has a slightly alkaline pH. As they grow larger they will become independent and fuss free.
For most varieties of lilacs it takes 3 to 5 years before they start producing blooms.
Lilacs bloom in the months of April, May and June. The bloom time depends on the local climate and current weather conditions and what type of lilac is planted. There are early, mid and late blooming varieties.
Most varieties of lilacs bloom just once, in the spring. Boomerang lilacs are a hybrid that bloom at least twice a year: once in the spring and again in the summer.
Full of charm and blushing with pink, purple and white flowers, lilacs bushes are a classic plant every flower garden should have.
Lilac bushes are picky about their soil quality: they need slightly alkaline soil that is well draining and fertile. These elegant flowers love full sun and need adequate air circulation.
Once established, lilac bushes are fairly independent. They just need some light pruning-done at the right time!
We hope you enjoyed this article on how to grow lilac bushes and we’d love to hear from you. Let us know in the comments all about your lilac growing adventures!