These wonderful plants will fill your yard with delicious scent.
When the lilacs begin to blossom, it is a solid indicator that spring has arrived for good. While many people only have a limited knowledge of common lilac (also known as French lilac) shrubs that can reach a height of 15 feet or more, there are now a lot more options available than there were fifty years ago. Some varieties that rebloom enhance the garden’s appeal the entire growing season.
How to Choose Lilacs
The common lilac is what you will most likely find when you go plant shopping. This traditional plant comes in a variety of cultivars and variations, each of which yields fragrant spring flowers in pink, purple, white, or even combinations of those hues. Common lilacs are typically the most fragrant variety of lilac and can grow to be rangy and large.
Rebloomers have arrived in the garden center thanks to recent introductions of hybrids between the common lilac and other shrub-type lilacs. Some of these more recent types are a little less fragrant, but they also tend to be smaller, bloom more frequently throughout the growing season, and have fewer powdery mildew issues.
The tree lilac is another common variety of lilac. It can grow to a height of around 20 feet and blooms with cream-colored flowers in the middle of the summer. Though it doesn’t require much trimming, keep in mind that the tree lilac is a tree, not a shrub.
Where to Plant Lilacs
Lilacs should be planted in full light (at least 6 to 8 hours per day), as too much shadow will prevent them from blooming. Lilacs also prefer moist, well-drained soil that is slightly alkaline.
When to Plant Lilacs
Before the ground freezes in the late fall is the ideal time to plant lilacs. After the earth thaws in the early spring, that is the next ideal period to plant. Lilacs will likely need to be planted as soon as you can locate them at the garden center, which is great; if you choose to do so during a warmer season, they might require additional watering.
How to Prepare the Soil for Planting Lilacs
A soil test should be performed prior to planting since lilacs thrive in slightly alkaline (6.5 to 7.0 pH), moist, well-drained soil that is high in organic matter. Lime must be added to raise the pH if it is below 5.5. It’s time to get the soil ready when you’ve obtained the ideal pH. Improve individual planting holes by mixing Miracle-Gro Garden Soil for Trees & Shrubs in a 50:50 ratio with the natural soil to give lilacs a nutrient-rich start. Iron and phosphorus are also present in this garden soil to promote root development and ward off leaf fading.
Does half shade cause lilacs to bloom?
Question:
Three years after being planted, a lilac has never flowered. Is there anything I can do to help the lilac bloom?
Answer:
Common or French hybrid lilac (Syringa vulgaris) cultivars may take several years (five or more) after planting to blossom. Before the bushes can flower, they must develop and become mature. Lilacs flower as soon as feasible when a good planting location is chosen and good cultural methods are used during the establishment phase.
Soil and Light Requirements
Lilacs thrive in full light and well-drained soil. At least six hours a day of direct sunlight should be provided for plants. Lilacs won’t bloom well if they are placed in partial shade.
It’s also crucial to provide good care over the first two or three years. Around each shrub, spread a 2- to 3-inch layer of mulch to retain soil moisture and keep weeds at bay. During dry conditions, water lilacs frequently. Additionally, enclose lilac shrubs with wire fencing in the fall to keep rabbits away from the plants’ foliage.
Even though proper cultural practices will promote plant growth, some of them may actually prevent flowers from blooming.
Fertilize Lightly
Lilacs don’t typically require fertilization. Lilacs can, however, be sparingly fertilized in the early spring. Heavy fertilizing may hinder flowering and encourage excessive vegetative growth.
Pruning at the right time is key
Flowering can also be impacted by pruning. Lilacs flower on growth from the previous year. Lilacs should be pruned as soon as they finish blooming in the spring. Many of the flower buds on lilac trees may be lost during winter, fall, or late summer pruning.
The common lilac typically doesn’t bloom until several years after planting, but a few other lilacs do. Syringa meyeri, the dwarf Korean lilac, Syringa patula ‘Miss Kim,’ and Syringa x prestoniae, the Preston lilac, all bloom within one to two years of being planted.
A lilac bush needs how much sun?
The Middle East is the origin of lilacs, which can grow as either a tree or a shrub. They draw everyone’s attention with their profusion of fragrant flower clusters. Compared to shrubs, which are typically smaller and more compact, trees are more sensitive.
What lilacs need to flower properly
For lilacs to properly flower, they need full sunlight. They need to be grown in an area with six hours of daylight each day. Additionally, they dislike being planted close to other trees because this could stunt their growth. Due to their solitary nature, lilacs should ideally be kept two to three meters away from other trees and buildings. You must plant them where the earth drains well because they do not like to have moist roots. Additionally, it is advised to shield them from chilly winds.
Tips for the maintenance of lilacs
Lilacs typically need little upkeep and care. When should a lilac be planted if you plan to purchase one? Your new tree or shrub should be planted in the spring or the fall.
Lilacs prefer neutral or slightly alkaline soils. Early in the spring, fertilize using a phosphate and potassium-rich fertilizer. It is advised to prune your plant as soon as the flowering is over. Remove any old, diseased, or dead branches at the same time. Your lilac will flower more the next spring if you also remove any withered blooms.
Water your plant at least once a week while it’s extremely hot outside.
Lilacs are plagued by a number of severe ailments and parasites. The most prevalent ones are Spanish fly, powdery mildew, bacterial blight, and leafminers.
The difference between lilacs and buddleias
Did you know that lilacs and buddleias, commonly known as “butterfly bushes,” are frequently confused with one another? Buddleias are less tolerant of the cold than lilacs.
Lilacs take far longer to grow than buddleias, which can grow up to eight feet in a single season. Buddleias may grow in a variety of soil types, including poor and calcareous ones.
Buddleias flower from summer through fall, but lilacs often bloom in the middle of spring. Their fragrant, vivid, and colorful blossoms, as well as the fact that both plants draw butterflies, are what most distinguish them from one another.
Where shouldn’t lilac bushes be planted?
Avoid planting lilacs in areas that will receive more than a half-worth day’s of shade because they thrive in full sun. Make sure to give them room to expand when you plant them. To find out the mature plant’s height and spread, read the label on the plant.
Lilacs require sufficient drainage to thrive. The soil should have just enough moisture to support the root system while still allowing for free drainage after heavy rains.
Dig a hole that is about 8 inches in diameter and 12 inches deep to test the drainage before planting. Add water to the hole. Choose a different location if the water hasn’t drained after an hour.
Are lilacs sun or shade lovers?
Full light and well-drained soil are ideal for lilac growth. Lilacs won’t flower well if they are cultivated in partial sunlight or shade. The bushes can live for hundreds of years after they have established themselves in a new location, even if it may take them three to four years to do so. The plant’s growth may be impacted by the soil pH (alkalinity or acidity of the soil). A slightly acidic to alkaline soil is ideal for lilac growth. Because of their frequent high acidity, New England soils may need to be modified for the greatest lilac growth.
Pruning the blooming stem back to a set of leaves each year will stop seed formation and ensure that there will be an abundance of flowers. Good flowering years may be followed by terrible years if this is not done. Winter trimming will get rid of flower buds since they are generated in the summer before they blossom.
Branch out any diseased, damaged, or dead wood. Renewing pruning is necessary for tall, lanky, and poorly flowering plants; for three years, cut around one-third of the oldest stems at ground level each year. This promotes the development of strong new stems from the base. The plant should have fully recovered after three years, with flowers growing back to nose height.
Despite how resilient lilacs are, they nevertheless require plenty of water as they grow. Lilacs prefer soil that is both moist and well-draining.
Powdery mildew fungus (Microsphaera alni), lilac borer (Podosesia syringae), and scale are the most problematic lilac issues in our region (oyster-shell scale, Lepidosaphes ulmi and prunicola scale, Pseudaulacaspis prunicola). The leaves appear to have pale streaks of powdery mildew on them. Even though it is ugly, it is rarely severe in our environment. In stems and larger branches, often one to two feet above ground level, borers leave 1/8-inch holes. A modest infestation may be disregarded, but more than a few borers require professional diagnosis and treatment. While prunicola scale covers bark with a dusty white mass, oyster-shell scale is appropriately named since the pests resemble 1/8-inch oyster shells on the stems. Control adult scale by chopping off branches that are extensively infested; control microscopic baby “crawlers” with a strong hose spray of water (use a hand lens to see scale). Summer oil and dormant oil both work well.
Is it possible to grow a lilac shrub adjacent to a home?
Lilac roots aren’t thought to be invasive, so planting lilacs close to a building’s foundation poses no risk as long as you give them adequate room. The average root spread for lilac shrubs is 1.5 times that of the shrub’s width. In most cases, keeping objects away from the foundation at least 12 feet (4 meters) will prevent foundation damage.
How long does a lilac shrub take to grow?
Lilacs produce flower buds for the following year after blossoming in the current year, just like other spring blooming plants do. Lilacs should be deadheaded as soon as they finish blooming to promote healthy bud growth for spring flowering.
- Deadhead: For larger plants, use a hedge trimmer or a hand pruner to remove dead flower heads down to a pair of leaves. Shear gently, just removing the dried flower heads.
- Renewal pruning: Renewal pruning promotes the growth and flowering of new stems while distributing more light throughout an older plant. Lilacs that have just been planted often don’t require trimming for 2 to 3 years, and it might take up to 2 years for a lilac to blossom. Lilac stems have a tendency to shadow out new growth at the base of the plant as they enlarge and become more like trees over time.
- Remove a third of the base of the thickest stems with a lopper or handsaw.
- Repeat this each year until all huge stems have been cut off.
- For smaller, thickly branching lilacs like Korean or Meyer lilacs (Syringa meyeri) that have overgrown, rejuvenation pruning is a strategy.
- Use a saw or hedge trimmer to chop the entire plant to the ground in the late winter.
- In the spring, fresh growth will emerge from the root zone.
- For one or two years, the plant might not bloom at all or only sporadically.
- Make sure to choose cultivars that are disease-resistant because powdery mildew is simply aesthetic.
Are lilacs contagious?
Ballistichory, also known as ballistic dispersion, is a unique way that lilacs disperse their seeds that causes the seeds to fly out in a large arc around the plant. The architecture of the seed pod produces this explosive effect by building stress in the woody fibers as they dry, which causes them to break at a planned weak point and fold back to release the seeds. The lilac can now spread its own seeds without the aid of wind or animals thanks to this technique.
Fungal diseases
This season, the Lilac Pseudocercospora leaf spot, a fungus, was detected in lilac samples examined by the Plant Disease Clinic. The same symptoms have been recorded (yellowing then browning leaves, dieback).
The PDC places a strong emphasis on sanitation because it appears that Pseudocercospora spores can survive on plant detritus for a number of years (leaves, stems, dead flowers, bark).
- To assist lessen the possibility of reinfection the next season, remove fallen leaves.
- Consistent watering and renewal cutting to reduce density will sustain the stressed plant.
Several of the plants in our landscapes, including lilacs, are afflicted by verticillium wilt. Verticillium dahliae and Verticillium albo-atrum are the two fungi that cause it. For a plant with this fungus infection, there is no cure.
- As a result of the fungi clogging the branch’s vascular system and preventing the transfer of water and nutrients, individual branches turn brown and die quickly.
- To increase plant longevity, increase watering and fertilization.
- The disease can spread across all sections of the afflicted plant, thus the best preventive is to buy resistant cultivars and practice proper hygiene.
Insects
The Lilac Borer, sometimes known as the Ash Borer, is a clearwing borer moth that creates tunnels in lilac stems.
- Frass, sap, and sawdust are warning signs (excrement).
- Some plants can withstand this harm.
- Others see branch dieback, and occasionally the entire plant dies.
- They won’t likely catch anyone’s attention.
Jeff Hahn, an extension entomologist, confirmed that no lilac borer samples have entered his lab this year.
Herbicide damage
Broadleaf weed treatments on lawns may volatilize, changing to a gas, and float onto unintended plants if sprayed during periods of extreme heat and humidity.
Cupping and browning, both indications of herbicide damage, would be visible in patterns:
- along a hedge’s one side but not the other,
- bushes positioned in or close to lawn areas, at the same level throughout their bases,
- and most critically, away from the area’s predominant winds.
Lilac hedges next to agricultural fields or other sizable herbicide-treated areas may experience damage in this manner.
How much water do lilacs require?
A traditional flower garden, outdoor space, or decorative pot should all contain lilac plants as they are a staple flowering shrub. Zones 3 through 8 are suitable for growing these fragrant shrubs, and they require very little maintenance. Lilacs need at least 6 hours per day of direct sunlight to produce their best flowers. Lilacs benefit from regular watering after initial planting, throughout active growth seasons (spring), and during prolonged dry spells. Lilacs are fairly drought tolerant once they are established.
It is advised to water your lilac plant once every 10 to 14 days from spring till blooming is finished. The ideal irrigation for lilacs is deep, infrequent watering. Make sure the planting space or container has good drainage. These plants don’t appreciate having their feet wet and won’t bloom if they are overwatered. By saturating air pockets with water and reducing soil oxygen levels, excessive water can strangle the lilac tree’s roots. The first indication that the lilac is overwatered is the plant wiggling.