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.
What does a lilac shrub look like when it is overwatered?
Overwatering your lilacs is one of the worst things you can do. If the soil around a particular lilac variety is always wet, then all lilac kinds are susceptible to fungal diseases including mildew, mold, and other sorts of fungi.
- If lilacs are overwatered, mold and fungus can harm them.
- Lilacs that receive too much water may have root rot.
- Your lilacs have received too much water if their leaves are yellow, pale, or withered.
- If your lilacs have been overwatered, let the soil dry to a depth of 34 inches (7.510 cm) before providing additional moisture.
Lilacs that receive excessive water risk developing root rot. A lot of the time, wilted, pale, or yellow leaves indicate an excess of water. Reduce watering to once every 14 days until these symptoms go away if any of these things happen or if the ground appears to be persistently damp. Remember that you might not need to water your lilacs at all if you are experiencing regular rains.
Do lilacs prefer shade or the sun?
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.
How do you tell whether a lilac plant needs water?
3. Take the plant out of its pot and place it in the hole. Make sure the top of the root ball is about an inch or more above the soil surface.
4. Apply the soil mixture all the way around the root ball, pressing it down firmly.
5. Take a long drink.
6. Mulch the area you just planted to a depth of 2 inches, being careful not to pile mulch up against the base of the plant. This will help keep the soil moist and prevent weeds from sprouting by denying them access to sunlight.
How to Water Lilacs
After planting, monitor your plants frequently, and water them once or twice a week, or anytime the top inch of soil becomes dry. While watering, count to 10 to make sure you’re providing each lilac plant with enough moisture. (If the plant becomes too dry, the leaves will start to droop.) You can reduce watering to every other week once plants have been planted and have had a few months to establish themselves. Lilacs won’t require additional water during the second growing season or later unless there hasn’t been rain in your location for a month or more.
How to Feed Lilacs
Lilacs should be fed Miracle-Gro Shake ‘n Feed Flowering Trees & Shrubs Plant Food after they have bloomed in the spring to encourage the development of robust roots. This plant food is jam-packed with nutrients for your plants, including kelp, earthworm castings, feather meal, and bone meal. These ingredients nourish soil bacteria, which in turn break down organic matter into nutrients for your plants.
How to Help Prevent Disease Problems with Lilacs
Powdery mildew is the main problem with lilacs, especially common lilacs. What’s the best approach to prevent this? Purchase and plant lilac cultivars that resist powdery mildew (check the plant tag or online description). Lilacs benefit from being planted in areas with good airflow. This fungus disease won’t respond to spraying, and it will finally go away on its own.
How to Deadhead Lilacs
Be sure to deadhead young lilacs as they start to bloom (this could take a few years!). Deadheading involves clipping off faded flowers at the base as soon as they start to droop and fade. In response, the plant will use more energy developing new flower buds for the upcoming spring.
How to Prune Lilacs
Although the newer, smaller lilac kinds require less trimming than the enormous conventional lilacs, all lilacs will grow more effectively and bear more flowers with regular pruning. Here are a few possibilities:
- Cut an older lilac shrub to 8 inches above the ground in late winter (March or April), then let it grow out if it isn’t flowering despite receiving plenty of sunlight. The following March, choose 8 to 10 of the best-looking stems, and reduce them by half. Trim the remainder to the ground. The following year, new blossoms should appear.
- Selectively prune 1/3 of the branches all the way back to the ground each year to revive shrubs that aren’t flowering well instead of chopping the shrub all the way down.
- Cut back branches to reduce size as soon as the shrub’s flowering has finished.
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.
Why are my lilac’s leaves curling?
The leaf miner insect and certain illnesses, such powdery mildew, are two of the most frequent causes of curled lilac leaves, however there are many other potential causes as well. It might also indicate that your lilac bush isn’t getting enough sunlight or water.
Curled leaves may indicate something that won’t ultimately harm the plant, but you can never be sure. This is the dilemma. This is why applying a pesticide or fungicide may be quite beneficial, since doing so will help the plant recover from any diseases it may have and enable it to develop robustly and healthily.
Once more, it’s critical to identify the issue as soon as possible because illnesses like powdery mildew can develop slowly at first but swiftly spread, which means your lilac shrub could perish without your knowledge.
In other words, curled leaves on a lilac bush are not always merely a cosmetic problem; they can also be a sign of far more significant problems. This includes ailments that could ultimately result in the plant’s death, therefore acting sooner rather than later is always the best course of action.
Do lilacs enjoy moist ground?
Lilac Fundamentals: Site Selection Consider the influence on traffic as lilac plantings grow in height and size to prevent them from becoming a danger.
An open space with good soil drainage is the ideal location for lilacs. For the most blossom, full sunlight is ideal. The amount of bloom will decrease as the amount of shade grows, although the shade throughout the day won’t significantly diminish flowering. Since lilacs dislike “wet feet” and will not thrive in poorly drained soil, good drainage is required. Lilacs can be planted inside of a berm that has been built in particularly damp places. Although newly planted plants require water during the first year for good establishment, lilacs can withstand some drought.
For the best landscape appearance and to minimize maintenance damage, mass planting is advised for all public spaces. A bed of lilacs planted with only one to one and a half feet of space will swiftly grow in, smothering weeds and protecting the plants from damage from mowers, plows, and other machinery. Filler shrubs can be added if wider spacing is required, provided there is a plan calling for their eventual removal. Better strategies include planting annual flowers in the first spot, covering it with textured mulch like bark, or using a ground cover like myrtle (Vinca minor) or pachysandra (Pachysandra terminalis).
Lilacs can live in a wide range of soil conditions once they are established, but newly planted plants need a well-drained soil with a pH between 6 and 7 otherwise they will grow extremely slowly. Organic matter will enhance drainage and moisture retention in less-than-ideal soil. Bone meal works well if organic fertilizer is required, but because the nutrients are released so slowly, it must be used before planting and mixed into the soil.
In their landscape planting guidelines, the New Hampshire Department of Transportation’s Landscape Division recommends the following mixture:
Each cubic yard of loam backfill must have the following ingredients added and thoroughly mixed in when replacing the old soil: (Note: One cubic foot is roughly equal to 4.5 bushels.) 4 cubic feet of peat moss, 10 pounds of fertilizer (10-6-4) with a minimum water insoluble nitrogen (W.I.N.) content of 35%, and 15 pounds of agricultural limestone that has been pulverized.
Although the fertilizer recommendations for the NH Department of Transportation blend vary slightly, it has been extremely effective in locations with poor soil conditions. The above loam backfill mixture was placed after the old soil was removed. A soil test should be performed in areas with suitable soil conditions to identify the nutrients required.
Lilacs can they get too much sun?
Lilacs should be planted where they will get at least 6 to 8 hours a day of direct sunshine because they love full sun. Interestingly, lilacs thrive in the heat of the sun throughout the growth season, but they flourish after a cold winter. Like all plants, lilacs are susceptible to overexposure to sunlight, which is shown by their curled, brown leaves and dried blossoms. Similar to how lilac blooms may not open if they are always in the shade and may become infected by fungi. The best course of action is to make sure they receive at least 6 hours of direct sunlight, ideally 8.