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.
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.
Which is better for lilacs: the sun or the shade?
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.
Lilac bushes should be planted when?
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 kind of space does a lilac shrub require?
Lilacs require a lot of space to grow, so that is the first planting rule. They will want a spot that is at least seven to eight feet broad for a hedge and 10 feet wide for a shrub.
Additionally, they require at least six hours of sun each day in order to bloom beautifully. Create an alkaline, well-drained soil. When planting, add a small amount of lime, and then apply it twice a year to keep the shrubs healthy.
Dig a hole for the plant about as deep as the pot or perhaps a little deeper so you can fill the hole with compost. To prepare the lilac roots for spreading out in their new home, remove it from the pot and score the roots. Backfill the hole after placing it in position. Add a little additional compost to the soil’s top layer for an extra boost of nutrients. Thoroughly water. The majority of lilacs are drought-resistant, so once the bush is established, you can let nature handle the watering.
How much time does a lilac shrub need to reach full maturity?
A lilac plant was given to me around seven years ago, and I planted it in our backyard. Each day, it receives several hours of direct sunlight. The leaves have always been a wholesome, mold-free green. It presently stands at about 7 feet. Every year, I eagerly anticipated the blossoms. The first blooms, consisting of two or three clusters of florets, appeared in the spring of 2011. There is only one this spring (now)! Can I do anything to ensure that the plant blooms the next spring?
A: One of the great things that gardeners look forward to each spring is the aroma of lilacs. I don’t think there’s much of a purpose to offer your lilacs significant yard space if they don’t flower. But there are a number of explanations for why they don’t blossom.
- Lilacs prefer a slightly alkaline soil (pH 6-7), even hydration, and lots of sunlight for optimal growth (at least 6 hours). Therefore, you might only get a few or no flowers if your soil is very acidic, it’s dry in the summer when the buds are growing, or your plant doesn’t get enough sun.
- Age: Lilac plants require time to develop before they start to bloom. Therefore, a young plant might not be mature enough to bloom if you have one.
Most plants begin to blossom after three to four years, while others might take up to seven. The first few years’ blooms will be rare, but they should become more numerous over time. If the plant you purchased was in bloom when you got it, then this is definitely not your fault.
- Pruning: Old wood is where lilacs bloom. They develop their buds during the summer so that by late January, they are completely developed and prepared to bloom.
So, two to three weeks after they bloom, or should have blossomed, is the ideal time to prune. Later trimming will reduce or stop flowering the following year. The plant can be kept healthy and flowering with yearly pruning. Remove any broken or dead branches first, then any old, woody ones, any that cross or rub, and then shape. Remove no more than one-third of the plant per year; nevertheless, if the plant is pruned on a three-year schedule, it will regenerate completely in just three brief springs.
- Overfeeding: Sometimes we solve one issue by causing another. Lilac typically doesn’t require further fertilizing. You will get a large, luxuriant plant but few, if any, blossoms if you feed your lilacs, especially if you use nitrogen-rich fertilizer.
Instead of flowers, nitrogen, the first number in a fertilizer indication, 10-5-5, encourages the growth of leaves.
- Transplant shock: Lilacs require some time to adapt. Even if a plant had blossoms when you got it, it is common for plants to take two or even three years to establish themselves and begin to bloom.
If none of the aforementioned scenarios apply to your lilac, you might want to offer the plant some stress, which is something we frequently do to wisteria that doesn’t blossom. A foot or so away from the lilac bush’s base, drive a sharp shovel’s blade into the ground. Cut the plant down, severing the roots on both sides.
I have two inquiries about tulips and daffodils. (1) What should I do with them after they’ve finished blooming? Do you want to base-cut them or deadhead them? (2) Where should I plant new flowers to replace them: immediately next to the bulbs? Do we remove all the green to make room for new blossoms in order to do this?
A: Although no one wants to hear it, the bare greens must be endured if you want to see the spring tulips and daffodils, even when they begin to look unsightly. The greens must stay, but you can tidy up the plants by trimming the flower stems to the ground. They shouldn’t be clipped, tied, or braided since they need to grow and store energy for the bloom the next year. The leaves can be removed from the bed and raked off once they have turned brown.
It is the same as putting perennials among the bulbs as far as that is concerned. Give them room to expand; take care not to disturb the bulbs when digging new planting holes; and, ideally, pick plants that will begin to grow just as the bulbs begin to fade. Daffodils and daylilies are a popular coupling that offers an excellent circumstance since the daylilies mature and cover the daffodil greens just as they begin to look pretty ragged.
Are lilacs shade-tolerant?
Respected Master Gardener: I see the enormous, aromatic shrubs at my grandparents’ property when I think of lilacs. Are there any lilacs suitable for small gardens, as my yard is pretty little? Could lilacs survive in partial shade?
Lilacs, or Syringa, are excellent shrubs for cold locations because they require chilly winters to thrive. They flourish in direct sunlight for at least six hours each day. Even though they can survive some shade, they won’t blossom as much. There are some lesser types of lilacs that thrive in our region, but many of them grow to be fairly enormous.
Syringa-Fairytale Lilac Series plants are upright, rounded, and bloom mid- to late in the season. They are hardy to 35 degrees below zero, grow to a mature size of 5 feet tall and 4 feet wide, and have good disease resistance. Tinkerbelle is pink, Prince Charming is lavender-pink.
Hyacinth Lilacs, or Syringa x hyacinthiflora, mature to a size of about 10 feet by 10 feet, so they might grow too big for your garden. Nevertheless, they are quite attractive, bloom early in the season, and are hardy to 45 degrees below zero.
Syringa meyeri, also known as the Meyer or Dwarf Korean Lilac, has a mid- to late-season bloom, is hardy to 35 degrees below zero, and matures to a size of 7 feet by 8 feet. Palibin is a smaller cultivar, measuring about 5 feet by 7 feet. Despite being referred to as “Korean lilacs,” they are actually Chinese in origin.
The late-blooming Syringa x prestoniae (Preston or Nodding Lilac) is hardy to 40 degrees below zero. At 10 feet by 8 feet, Donald Wyman might be too enormous for your garden, while Coral and Hiawatha reach mature sizes of 7 feet by 6 feet and 8 feet by 6 feet, respectively. Hiawatha has exceptionally attractive magenta buds and is powdery mildew resistant.
Miss Kim, a variety of Syringa pubescens (Manchurian Lilac), is well known. It flowers late in the season and is hardy down to 35 below zero. Its mature dimensions are 6 feet tall by 6 feet wide. This species produces small, abundantly blooming blooms and is resistant to powdery mildew. The color of Miss Kim is lavender-blue.
The Common Lilac is Syringa vulgaris. This species has a wide range in size, is hardy down to 40 degrees below zero, typically blooms in the middle of the season, and frequently has a potent scent. Smaller varieties that thrive in our region include Albert F. Holden, a silvery purple that measures 8 feet by 7 feet, Avalanche, a white that measures 8 feet by 6 feet, Lucie Baltet, a pale pink that measures 5 feet by 5 feet, Marie Frances, a pink that measures 8 feet by 6 feet, Prairie Petite, a pink-lavender that measures 3 feet by 3 feet, Sarah Sands, a dark purple that measures 8 feet by 6 feet (lavender-blue, 6-feet by 5-feet).
Respected Master Gardener: Which perennials ought I remove right away, and which should I wait until spring?
Gardeners frequently want to trim back all herbaceous plants and straighten up the yard before the snow arrives, but some perennials shouldn’t be pruned at all because they support wildlife or add color and interest to the otherwise drab Minnesota environment throughout the winter. Heuchera, tiarella, dianthus, moss phlox, and hellebores are examples of low growing evergreen or semi-evergreen perennials that shouldn’t be clipped back.
For extra crown protection, leave the foliage on the following perennials until spring: Aster, Astilbe, Chrysanthemum, Delphinium (cut stems to basal foliage), Hosta, Lady’s Mantle, Penstemon (cut tall foliage to basal growth), Russian Sage, and Salvia (leave the foliage on until spring) (cut back to basal growth). You may maintain track of some perennials by keeping a section of them in place. Examples are Asclepias, Platycodon (balloon flower), and hardy Hibiscus. These perennials emerge late in the spring.
Some perennial plants have fascinating seed pods or flower heads that make the garden interesting in the winter. Flowers like Baptisia, Achillea, Sedum, and Joe Pye Weed can all be left in situ to add color to the garden in the late fall and winter. The plumes of various ornamental grasses, particularly feather reed grass, can enliven the winter environment with intrigue and vertical accents. Trim back grasses in the early spring before new growth appears to protect tender shoots.
Some perennials can be left until spring even if they may not be very appealing since their seed heads provide food for birds. These include Heliopsis, Rudbeckia (black-eyed Susan), Echinacea (coneflowers), Monarda (bee balm), and Coreopsis. If not deadheaded and left in place, some annuals, such as zinnias, bachelor’s buttons, and cosmos, also provide food for birds.
Hemerocallis (daylily), Brunnera, Bearded and Siberian Iris, Phlox (not moss phlox), and Veronica are perennials that you are free to remove right away. Cut down any unhealthy or contaminated plants you may have, and then get rid of the plant matter. After the foliage turns brown and collapses, herbaceous peonies can be pruned back to the ground. Be cautious not to disturb the reddish buds off to the sides, though, since they will grow stems the following spring.
Respected Master Gardener: My yews were practically reduced to skeletons last winter by something. They had a slight resurgence this summer, and I want to shield them from harm this winter. What do you suggest?
The culprits are probably rabbits and deer, both of which enjoy yew trees. Your best bet is usually to use repellents and limits together. You can use any commercial deer and rabbit repeller, but make sure it is labeled for those animals and is used in accordance with the directions. Applications will be required all winter long. Making circular cages out of hardware cloth or another type of fence material with mesh apertures no larger than one inch will restrict access. The cages must be four feet tall and large enough to be used as the plant develops. Secure cage bottoms that are buried many inches. They will be further shielded from winter winds and storms by two or three three-quarter-diameter metal or bamboo poles weaved vertically down the cages and buried in the ground. Other priceless and vulnerable shrubs can also be caged to keep animals out.
- Rakes, hoes, shovels, spades, and digging forks should all be clean. Cleanse with water after removing dried dirt with a brush. To avoid rust, wipe down tools with an oil-soaked rag after they have dried. Wooden tool handles can be moisturized and lubricated using the same rag.