What better time than now to ensure that lilacs continue to bloom as long as possible, given that they are currently in bloom in many parts of the country.
The following care advice from horticulturist Paul Parent will help you get the most out of your lilacs and extend their life.
- During the hottest months, lilacs grow best with a minimum of 1 inch of water per week.
- They won’t bloom if you fertilize them excessively. Overfertilized plants don’t produce fragrant flowers; they just produce attractive foliage. Feed your lilacs in the spring with something like Plant-Tone.
- Sweet soil is ideal for lilac plants. This indicates that they thrive in areas with pine or oak trees nearby. At the start of spring, distribute the lilac or add limestone, wood ash, or comparable items at a rate of 1-2 handfuls per 3 feet tall.
- On aged wood, lilacs blossom. As soon as the flowering is finished, you should prune in the spring. You will lose the fresh bloom buds for the following year if you wait too long.
- Take out the oldest canes and decaying wood when pruning. Cut those off at ground level, between 5 to 10 inches.
- To keep lilacs from flowering again, take out 1/21/3 of the old wood each year. Reduce the tallest portions to 5–6 feet in height.
- Hardy lilacs can be grown in Zones 37, but they struggle to grow in regions with extremely warm conditions.
How is a lilac tree maintained in good health?
Lilac trees don’t require much care as they develop, but a little bit of maintenance will enable them to reach their maximum size and produce more of those wonderful blooms. The following are some steps to take when caring for lilacs:
- Apply a thick layer of mulch every year to keep moisture in and keep weeds under control.
- The common lilac trees should not be watered until the top is completely dry.
- Sparingly fertilize your lilac plants. A quality fertilizer applied in the late winter will be adequate for the remainder of the year.
- When it comes to caring for lilacs, correctly pruning them comes first on the list of things to do. Once the blossoms have stopped, trim them. They get stronger than previously as a result of this.
- The plant will produce more blossoms if you deadhead lilacs. Additionally, it will enhance the appearance of the plants.
- Keep grass away from the lilacs’ roots to encourage better flowering.
How should a lilac tree be pruned?
Cutting off the tops of stems that have grown out of control is frequently insufficient when pruning lilacs. It is typically preferable to remove the entire stem. The best way to trim lilacs is with clippers. To avoid spreading and promote later blooms, remove spent blossoms right down to the stems. Three-quarters of the branches should be pruned. Remove any shoots that are emerging from the main trunk and are growing close to the ground. Lilacs within the inner branches may need to be trimmed in order to increase air flow or let more light through.
However, it may be essential to prune the entire bush or tree to approximately 6 or 8 inches (15-20 cm) above the ground if lilac shrubs are already too big or starting to look unpleasant. Remember that it takes around three years for flowers to grow after the entire bush has been removed, so you might have to wait.
When should a lilac tree be pruned?
A lilac shrub needs to be pruned every year once it has reached the age of two. Early summer is ideal for cutting grass because the flowers have already flowered and withered. Here are some tips for taking care of lilac shrubs and trees.
Lilacs produce the flower buds for the following season in the early summer, right after their blooms have faded. You run the danger of removing the budding buds if you delay trimming until later in the growing season.
This also holds true for lilacs that bloom twice a year, like Bloomerang Purple. After the bush’s initial bloom, you can prune it to promote new growth and more flowers in the second bloom, which occurs in early fall.
Lilacs eventually only bloom at the tips of their highest branches if allowed to develop naturally. Lilac bushes can be revitalized and made more visually appealing by pruning to maintain a balance between older stems and young blossoming branches.
Pruning a lilac shrub involves a number of techniques:
- First, remove any weaker branches and any dead, broken, or diseased stems. Branches should also be trimmed to avoid rubbing or crossing.
- Old stems that are thicker than two inches should be cut off. This controls the height of your lilac plant and promotes the development of new shoots. It is best to thoroughly remove the stems.
- Control sucker emergence. Suckers are fresh branches that sprout from the plant’s base. The main branches can be replaced by a few robust suckers, but any lesser suckers should be removed at the soil line to prevent them from robbing the plant of nutrients.
Last but not least, here are some general guidelines for pruning lilacs:
- Lilac bushes that are mature should only be pruned to a height of 6 to 8 feet.
- Aim for 10 to 12 primary stems, each of which should be between 1 and 2 inches thick.
- Never remove more than one-third of the bush with pruning.
- Older stems and fresh blossoming shoots should be balanced.
Are lilac trees challenging to care for?
Lilac bushes require little general maintenance because they are low-maintenance shrubs, with the exception of periodic trimming.
Lilacs may withstand a variety of soil types, although they prefer humus-rich, well-drained soil. In order to make a good planting soil for them, incorporate compost into the soil. Lilacs prefer to have their roots kept dry, therefore they should be irrigated properly but sparingly.
It is not required to fertilize lilac trees frequently. However, if there isn’t too much nitrogen present, which would cause insufficient flowering, fertilizing in the early spring may assist promote flowers.
Lilac plants are typically hardy, but occasionally they are plagued by insect pests like borers. Watch for any indications of a pest problem and take fast action to treat it. Sometimes treating insects with a soapy water spray will be adequate. For the care and health of lilac trees, however, it can be essential to completely prune the plant if there are severe infestations.
Pruning is crucial for lilac maintenance. Lilac plants should be well-pruned to reduce the risk of diseases like powdery mildew.
What is lilac tree dying in my yard?
The most typical tree disease that affects lilac trees is powdery mildew. Plants with this fungal infection develop more slowly, and in certain situations, they may die. Watch out for a white, flour-like substance on the leaves of your lilac plant. If you do have powdery mildew, get rid of all the affected plant portions and use a fungicide.
Inquire about scale, lilac borer, and other problematic pests from your tree service professional.
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.
Herbicide damage signs like cupping and browning would appear 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.
Do I need to deadhead my lilac tree?
Lilac should be mulched every spring. You can deadhead spent blooms on smaller shrubs as the blossoms start to fade in the middle of the summer. After flowering, prune shrubs to the desired height and form, and remove any dead, diseased, or dying wood.
When pruning an ancient tree that has become overgrown or lanky, do it during the plant’s dormant season, which is winter. Lilacs react well to rigorous pruning, and the entire plant can be cut back to a height of around 1 m. You won’t see the blossoms for at least a year because they bloom on wood from the previous year. Alternately, you could prune back some of the stems over the course of two or three years and remove some of them; this will guarantee that you still get to enjoy some springtime blooms.
What distinguishes a lilac bush from a lilac tree?
Lilac bushes (also known as shrubs) are characterized by their numerous woody stems that emerge from the plant’s base. In contrast, the trunk of the majority of lilac trees is the only woody stem. However, your neighborhood garden center might also sell shrub lilacs that have been grafted onto a single stem to give them the appearance of miniature trees.
The choice between a lilac tree and a lilac bush is typically determined by the amount of space available. Lilac bushes come in a range of sizes and can be placed in more compact areas of a garden. A lilac tree requires space to reach heights of 20 feet and widths of 15 feet. Both require sunlight to bloom well.
Are dead lilac blossoms to be removed?
The removal of spent flowers to encourage new blooming—deadheading—is a crucial part of lilac maintenance. Lilacs should be deadheaded as soon as the flowering is finished to allow the plants to grow robust, healthy buds that will flower vivaciously the following year. According to the University of Minnesota Extension, you can use a hand pruner, but larger plants could require a hedge trimmer. Only the dead blossom should be removed; the plant should still have two leaves.
According to the Chicago Botanic Garden, you should prune lilacs at the same time as you deadhead them since they set the blossoms for the following year quickly after flowering. By doing this, you can prevent damaging or removing the developing buds. Three to four years after planting, you should start pruning lilacs. It might be necessary to trim back overgrown lilacs to just a few inches above the ground. Winter is the ideal time to complete this. In this instance, it will take the shrub one or two growing seasons to start blooming once more.
How are lilacs kept from blooming?
- Keep the grass from growing around lilacs to enhance blossoming. The grass will be kept down by placing a 16- to 24-inch circle of landscape fabric around the bushes and covering it with bark or stone.
- Cut lilac branches should be forced into a winter bouquet. The cut ends should be bruised and placed in water. The branches need frequent spraying. When they bloom, keep them in a cool location; after that, move them to a warmer location to show.
- When Abraham Lincoln passed away, poet Walt Whitman had lilacs in mind:
I cried and will continue to cry as spring keeps coming back as the lilacs in the dooryard bloomed for the last time.
- Lilacs are said to represent youthful enthusiasm. Discover more about floral symbolism here.
Do lilac trees produce flowers every year?
The majority of lilac shrubs bloom each year, but poor trimming can prevent flowers from appearing the following year. When it comes to properly pruning lilac shrubs, time is crucial because the buds for the bush’s blooms the following year are formed quickly after the bush has completed blooming.
After the new buds have formed, pruning your lilacs may result in few or no blooms the following season. It can take several years before you see any flowers if you prune your lilac bushes too aggressively. The best course of action is to deadhead faded flowers and, if required, prune your lilacs immediately following the blooming period.
How much may a lilac tree be pruned back?
Cutting no more than a third of the stems from a shrub should be the general guideline when pruning it. While a result, the plant will continue to thrive and grow new stems as the old ones bloom. Your aim is to grow a lilac bush with between eight and twelve stems, all between one and two inches in diameter, and of varying ages.
Prune Unsightly Features
Pruning should start with the removal of diseased, dead, and pencil-thin suckers and twiggy growth. Trim these all the way to the ground. These stems are typically handled by pruning shears or loppers.
Remove Any Stems Thicker Than 2 Inches in Diameter
By routinely removing entire old stems, you can keep your lilac from growing too tall. Removing only the tops of lengthy stems might cause the plant to take on an unusual, unnatural shape. A pruning saw could be essential for stems that are quite large. It can be difficult to handle thick lilac stalks.
Prune Remaining New Stems
Pruning the remaining new stems to an outward-facing bud will encourage your lilac to fill out more and develop a shrubby appearance. This entails trimming just past buds that point away from the plant’s core. A denser shrub will result from this technique’s increased branching.