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.
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.
Where should a lilac tree be planted for maximum benefit?
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.
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.
When should my lilac tree be trimmed?
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.
How can a lilac tree be made to bloom?
Although there are several potential solutions to this problem, pruning might hold the key. Lilacs blossom on the growth from the previous year, so it’s crucial to cut them as soon as the spring blooming is through. Pruning a lilac in the summer, fall, or winter may result in the removal of buds that would have bloomed the following spring.
After the spring bloom, try to only lightly prune the plant. If you want to avoid delaying the next bloom by drastically pruning your lilac shrub, simply remove the oldest and heaviest branches and trim the inner branches to make room for sunshine to enter the bush.
Take into account the age of your lilac bush, which by this point may have evolved into a tree. On younger wood, lilacs bloom at their best. If the majority of your lilac’s structure is old, decayed wood, blooms may be scarce. An elder lilac can require rejuvenation pruning, followed by a two- to three-year wait before it can bloom fully again.
Which fertilizer is ideal for lilacs?
Lilac plants don’t require a lot of food or fertilizer. A 10-10-10 fertilizer mixture applied yearly in the early spring is what we advise. (The amounts of nitrogen, phosphorus, and potassium, or NPK as they are popularly known, are represented by the digits 10-10-10 in the formula.) Early spring fertilization of lilacs with a high phosphorus solution encourages blossoming.
Coffee grounds and grass clippings are also excellent sources of nitrogen. Use in moderation since an excess of nitrogen in the soil can lead to subpar blooms. The ideal soil conditions for lilacs are slightly alkaline (6.5–7.0 pH), wet, and well-drained. The soil may become more alkaline by adding bone meal to it. Use Miracle-Gro Shake ‘n Feed Flowering Trees & Shrubs Plant Food in the spring if you decide to feed your plant. Last but not least, lilac plants dislike acidic soil. Epsom salts can be used to encourage blossoming while the plant is dormant.
Do lilac trees develop quickly?
The lilac is a multi-stemmed, deciduous shrub with an erratic, rounded shape. When young, it grows quickly, but as it ages, its growth slows to roughly one foot every year. The stems’ sturdy wood has a dark gray to gray-brown color. The leaves are light green underneath and dark green to blue-green above. The clusters of four petal blooms, which come in lilac, light purple, or lavender hues, bloom in April or May. They have a strong fragrance. Although the lilac thrives best in sunny locations, it cannot stand hot, muggy weather. It requires moist, well-drained soil that is neutral or just a little bit alkaline in pH. Peat or leaf mold can be added to the soil as a supplement. As soon as they start to fade, old flowers should be removed. Lilacs should be pruned as soon as they finish blooming. Pruning the shrub is preferred since it will highlight the medium-aged wood, which will still contribute to the plant’s good size and produce nice blooms. Remove a third of the earliest stems at ground level each year to accomplish this. Any remedial trimming, like removing competing branches or sucker growth, can be done concurrently. Pruning older lilacs as small, multiple-branched trees will highlight a few massive, old trunks while removing sucker growth and making them a focal point of the landscape. The shrub can also be pruned into a tree with a single stem. Lilacs that are overgrown can be pruned to a few inches above the surface. They will bloom once more in three to four years, Depending on the mature height, space your plants 3–4 feet apart if you want a hedge.
How old are lilac trees?
Lilacs are renowned for their longevity and hardiness.
Numerous lilac shrubs reach ages of greater than 100. They frequently outlive the residence of the gardener who planted them due to their extended lifespan. As a result, if you’re driving along a country road and come across a few what appear to be random lilac bushes, it was probably a farm or house a century ago.
Try growing lilacs in your garden if you haven’t already. They not only return every year, but they also put on a display for the senses with vibrant blossoms and enticing scents. Lilacs have a lot to offer, and learning about their history demonstrates just how unique these plants are.
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.
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.