Did you know that the National Gardening Bureau has designated 2022 as the “Year of the Lilac”? They have a sweet, eerie aroma and are among the easiest shrubs for your landscaping to maintain that bloom in the spring. Find out how to plant, nurture, and prune your lilacs.
About Lilacs
Syringa vulgaris, or common lilac, is prized for its tenacity, dependability, and scent. Lilacs are so hardy that they can live for more than 100 years and frequently outlive the houses they were planted near.
This tiny, multi-stemmed deciduous shrub (or tree) has approximately ten canes and blooms at eye level. The height of a common lilac can range from 8 to 12 feet, depending on the cultivar. The aromatic flowers attract butterflies and make good cuttings.
There are lilac types that come in white, cream, and even pink and yellow, though the blooms are typically lilac/purple in hue (ranging from very pale to extremely dark). Flowers can be solitary or double in number.
Lilacs bloom in northern states from mid- to late spring for around two weeks. However, there are lilac varieties for early, mid, and late seasons that, when cultivated together, guarantee a consistent bloom for at least six weeks.
Lilacs do best in soil that is fertile, humus-rich, well-drained, and neutral to alkaline (at a pH near 7.0). Add compost to your soil to improve it if it is in bad condition. (Learn more about adding amendments to the soil and getting it ready for planting.) Lilacs don’t enjoy having their feet wet and won’t blossom if they are kept too moist, so make sure the planting area drains well.
Lilacs should be planted in full sun, which is defined as having at least six hours of sunlight each day, for the finest blooms.
How to Plant Lilacs
- If you’re fortunate, a friend may offer you a sucker, or offshoot, of the plant’s root system. The sucker will first appear pitiful, but all you need to do is dig a hole, fill it with soil, and then insert the sucker. water next, and then wait. You’ll be rewarded with enormous, fragrant blossoms in 4 or 5 years.
- Lilacs purchased from nurseries can also be planted easily. If the plant was cultivated in a container, spread its roots out as you plant it; if it was balled or burlapped, gently remove the covering and any rope before doing so. Set the plant 2 to 3 inches deeper than it was while it was growing in the nursery and cover the roots with topsoil. in water Then add more topsoil to the hole to finish it.
- Depending on the kind, place multiple lilac bushes 5 to 15 feet apart.
- Apply a layer of compost under the plant each spring, followed by a layer of mulch to keep moisture in and weeds under control.
- If the weekly rainfall is less than 1 inch, water during the summer.
- If lilacs receive too much fertiliser, they won’t bloom. In the late winter, they can manage a few 10-10-10, but no more.
- Spread some lime and thoroughly composted manure around the base of your lilac bush once it has finished blooming. Remove suckers while you form the shrub by trimming it.
Pruning Lilacs
- Since lilacs blossom on old wood, it’s important to prune in the spring immediately following their bloom. You risk removing the wood if you prune later in the summer. A word of advice: It’s time to prune if your lilac flower clusters are getting smaller!
- After bloom each year, cut away any dead wood. Remove the oldest canes by pruning (down to the ground). Take out the tiny suckers. Reduce weak branches until a robust shoot remains. Reduce tall canes to eye level.
- Remove one-third of the oldest canes (down to the ground) in year one, half of the remaining old wood in year two, and the remainder in year three if your lilac is very old and in poor condition. Cutting the entire plant back to a height of approximately 6 or 8 inches is another option for elderly lilacs. Although it sounds dramatic, lilacs are remarkably resilient. This option’s drawback is that it takes some time for the hair to grow back. The lilac will grow back bursting with blooms, so there will be less work and more reward.
- It is important to understand that extreme trimming causes bloom loss for one to three years. For these reasons, a smart pruning programme gives the bushes yearly attention in an effort to avoid making dramatic and severe cuts.
The Syringa vulgaris kind of lilacs is the most widely grown and fragrant:
- Try the double magneta variety “Charles Joly” for an early bloom.
- Lilacs in the middle of the season include “Monge,” a deep reddish purple, and “Firmament,” a delicate blue.
- Miss Canada, a reddish pink, and Donald Wyman, a solitary purple, are two late-season beauties.
Syringa x hyacinthiflora, an early-flowering lilac cultivar, opens 7 to 19 days before those of the common lilac. Its fragrant blossoms attract butterflies and hummingbirds.
The cutleaf lilac, a fragrant pale lavender, is one of the common lilacs that may flourish as far south as Zone 9. Common lilacs appreciate cold weather. The beautiful shrub Syringa patula ‘Miss Kim’ has light lilac-blue flowers that eventually become white.
There are tiny kinds for gardeners who simply don’t have the space for the conventional larger lilacs, particularly those in urban settings. Even in a container on your balcony or patio, they will grow.
- ‘Baby Kim’ has a lovely rounded shape, only grows 2 to 3 feet high (and 3 feet wide), and has purple flowers that draw butterflies. Hardiness from Zones 3 to 8 extended.
- Compact lilac ‘Little Lady’ (Syringa x) has dark pink buds that open to lilac-pink flowers and grows to be 4 to 5 feet tall and wide at maturity. Zones 2 to 7 are tough.
- Syringa vulgaris cultivars “New Age Lavender” and “New Age White” were developed for mildew resistance and are quite compact, growing from 4 to 5 feet tall and wide. Hummingbirds and butterflies are drawn to their fragrant blossoms. Zone 4 hardy.
Do lilacs have shallow or deep roots?
Lilac shrub roots are quite rare to penetrate the side of a foundation. Lilac roots typically become damaged when they get too close to the soil-level foundation’s base. Lilac roots can only penetrate shallow foundations because of their shallow root systems. It is unlikely that you will sustain harm if your foundation is deep.
Lilacs can also cause foundation damage if the soil is thick and expands when wet and contracts significantly when dry. When there is a drought, the feeder roots draw a lot of moisture from the soil at the tips, which causes it to drastically shrink and can lead to cracks in the foundation. After a heavy rain, the soil fills once more, but the foundation still has fissures. Regardless of the distance between the foundation and the shrub, damage to foundations is unlikely in instances when the soil is light and the foundation is deep.
There is a slight possibility that lilac roots will obstruct water and sewer lines. Lilac roots choose the easiest route to sources of nutrients and water. They are more likely to enter leaking water and sewage lines than sound pipes, though. However, there is little chance of damage if your lilac shrub is located 8 to 10 feet (2-3 m) from water and sewer lines, even if the pipes are cracked.
Which month is ideal for lilac planting?
Lilac trees grow best in the fall, just after the leaves have fallen and before the ground freezes. Lilacs can be planted in the spring before the buds open. However, springtime is a relatively brief season, therefore transplanting at this time is only advised in regions with really harsh winters.
How should a new lilac bush be planted?
The ideal season for planting lilac plants is spring or fall. Make the hole deep and wide enough to fit the lilac’s roots, and then plant it with their spread vertically in the ground. Even if you intend to use them as privacy hedges, you should leave at least 5 feet (1.5 m) between each lilac bush you plant to avoid overpopulation.
A location with lots of afternoon sun and well-drained soil is ideal. Lilac bushes need adequate drainage, so wherever possible, planting lilac shrubs in somewhat higher locations is advised. Lilac bushes should be planted, then given plenty of water and a coating of loose mulch. Keep the mulch light enough not to hold too much moisture, yet thick enough to keep out weeds and preserve some moisture.
What is the rate of growth of a lilac bush?
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 grey to gray-brown colour. 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 mould 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.
Are lilacs suited for coffee grounds?
Lilac plants don’t require a lot of food or fertiliser. A 10-10-10 fertiliser 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 fertilisation 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.
How much does a lilac root ball weigh?
Ivory Silk, a type of lilac tree, can grow up to 30 feet tall and 25 feet wide. Ivory Silk grows in full sun and is cold hardy in USDA Plant Hardiness Zones 4 through 7a. Even as a young tree, it provides an abundance of summer blossoms. Since the lilac tree is dormant in the fall, that is the perfect time to dig it up. A lilac tree’s deep and extensive root system frequently results in a big rootball that requires the assistance of two or more people to remove from the ground.
At a height of four to five feet off the ground, at breast level, gauge the tree trunk’s diameter. The diameter of a lilac tree at breast level is a good indicator of the rootball’s size, according to a study published in the Journal of Arboriculture.
To determine the rootball’s approximate diameter, multiply the trunk’s diameter by 14.
- Ivory Silk, a type of lilac tree, can grow up to 30 feet tall and 25 feet wide.
- A lilac tree’s deep and extensive root system frequently results in a big rootball that requires the assistance of two or more people to remove from the ground.
Create a trench that is wide enough to fit the rootball all the way around the tree. Use flour, spray paint, or a garden hose to mark the cut line. Put the spade into the dirt as far as it will go while standing outside the circle and facing the tree. Make a V-shaped trench by pushing the shovel in the direction of the tree.
Continue to remove as much of the rootball as you can by digging down and into the lilac tree’s centre. To release the roots, clear the earth using a shovel. When the rootball has as much of the root system as feasible, a transplanted lilac tree has a higher chance of surviving.
- Create a trench that is wide enough to fit the rootball all the way around the tree.
- Make a V-shaped trench by pushing the shovel in the direction of the tree.
Move the lilac tree to one side and place a piece of canvas that has been rolled below the rootball. Roots that go beyond the anticipated rootball diameter should be removed with loppers. Unroll the canvas while pushing the tree in the opposite direction. Wrap the trunk and rootball in the canvas.
Remove the rootball from the hole and tie the canvas tightly around the trunk with twine, wire, or a strong cord. Use a wheelbarrow or garden waggon to move the lilac tree to its new site.
By affixing a rag or other marker to a limb facing north, indicate the tree’s north side. This will make it easier for you to move the tree and keep it pointed in the same direction. A lilac tree with a 1 1/2-inch diameter has a rootball that is 22 inches in diameter, whereas one with a 6.3-inch diameter has a rootball that is 83 inches in diameter.
Without tree removal equipment that can dig deeply enough and sustain the weight of the rootball, moving a rootball with a diameter greater than 3 feet is not practical.
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 fibres 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.
Selecting a Planting Site
Please follow these recommendations when picking a location to plant your cloned lilacs.
- Pick a location that is not shaded and is free of any obstructions like trees or buildings. (An obstacle’s minimum distance from the base should be at least twice as tall as the obstacle.)
- Pick a location that is as far away from highways, sidewalks, and footpaths as you can.
- To prevent any influence with the station instrumentation, plant the cultivars at a distance of 12 to 15 metres (40 to 50 feet) from weather stations.
- Pick a location where you can easily keep an eye on the plants every day.
- Pick a location where there is no chance of humans or animals trampling the plants.
- Pick a location where severe snow accumulation from ploughing or drifting won’t occur.
- Choose a level surface wherever possible; if your environment is hilly, try to stay away from any low regions that can unnecessarily delay spring shrub development.
- Plant in soil that is typical of the area; stay away from gardening in soil that has had a lot of manure or compost applied to it.
- At least 5 m (15 ft) should separate plants.
- Pick a spot where there won’t be any unique microclimates for the plants (such frost pockets or windy slopes).
You should follow the following guidelines to ensure the health of your bushes because the quality and authenticity of your data are heavily dependent on them.
- If the plant is “bare root” (not in soil), immerse the roots in a bucket of water for a few hours as soon as you obtain it. If the plant is in a pot, make sure the soil is moist and add water as necessary before moving on to the next step.
- Dig a hole that is just broad enough to accommodate the roots and deep enough to barely cover them.
- Superphosphate or bone meal should be added to the soil where the plant will be planted in an amount of roughly 1/2 cup. Add equal portions of peat moss or compost to backfill soil in heavy clay or very sandy soils to enhance growing conditions.
- For the first month, water the new transplant at least once a week until the soil is completely saturated.
- During the first growth season, use either a dry fertiliser like 10-10-10 or a liquid soluble one as directed on the label.
Annual Care
- Each plant should have an even 1 cup (1/8 Ib or 50 g) of 5-10-10 fertiliser applied around it. Stakes made of shrub fertiliser could be used instead.
- Mulch the soil with peat moss, bark, well-rotted sawdust, wood chips, or another similar organic material to keep grass and weeds out of the area 30 cm (1 ft) around the base of each plant.
- You might need to water the plants if there is a prolonged dry spell.
Pruning
To keep plants in good health, they should be pruned every 5 to 10 years. Lilacs should be pruned as soon as they bloom in the spring because new wood that emerges after bloom develops flower buds for the following year. Avoid pruning in the fall since it will kill the buds for the next year. If desired, take off old, dried-up blossoms to avoid the shrubs looking ugly.
On the other side, honeysuckle should be clipped during the dormant season. Only in warm climes where plants do not lose their leaves in the cold is midwinter pruning advised. As a general rule, prune the plant about a month before it typically starts to leaf out or about six weeks before it reaches the first leaf stage.
In order to preserve the desired size and shape, one or more of the older main stems at the base of the plant for both species may be removed, and some, or all, of the remaining stems may be clipped back. Never take out more than a third of the plant at once.
Pests
Lilacs and honeysuckle are comparatively pest- and disease-resistant plants. On rare occasions, they could be impacted by aphids, scale, or powdery mildew on the leaves. Rarely are control methods necessary unless there are scales (on lilacs) or aphids (honeysuckle). Regular treatments of a pesticide may be required should these ailments or insects develop into major problems. For the most recent control advice, get in touch with the Agricultural Extension Service in your state, province, or county.
Protection
Next to each new plant, place a wooden or metal stake to clearly mark its location. By doing this, accidental damage from lawnmowers or people will be reduced. In some areas, animals like mice and rabbits can seriously harm the plants. Guards made of wire-mesh around the plant bases help to prevent such harm. In regions where deer or other large animals browse, larger wire guards will be required to protect the entire plant.
2 to 4″; (5 to 10 cm) of mulch at the base of each plant will shield its roots from frost damage for winter protection in regions with low snowfall. Wrap stems loosely with twine to minimise ice breaking, or cover the plant with burlap (from a feed bag, for example) on a frame. Avoid using plastic.