Last updated on October 22nd, 2023 at 01:54 am
Growing lilacs from seed is just one way to propagate these fragrant plants. Lilacs grown from seed may be similar or different than the parent plant, as these new plants will be hybrids. Learn how to grow lilacs from seed, and fill your garden full of beautiful lilac bushes.
There is nothing quite as beautiful in late spring than a lilac bush full of fragrant blooms.
The purple and cream-colored flowers make fabulous cut flowers, and are long lasting in flower arrangements. Just make sure that you prepare and condition the flowers and stems, to help keep the lilacs from wilting in the vase.
The blooming time is short but sweet, and every year I wish that I had more lilacs growing in the garden.
The old lilac bushes at the farm have been growing there for generations. Last year I decided that it was time to add some fresh and new lilac bushes to the garden.
I made an effort to increase my lilac stock, be propagating the old lilac bushes using several techniques.
The propagation methods used included:
- propagation through lilac stem cuttings
- propagation through root shoots and suckers
- and propagation by planting lilac seeds
At the end of the growing season, lilac seed pods were harvested from the bush, at just the right time, to ensure a collection of fresh and viable seeds.
There were lots of lilac seed pods in the harvest, and the lilac seeds were saved for planting.
The seeds within the pods were given a period of cold moist storage for stratification, mostly in the fridge, although some were also winter sown in milk jugs.
Growing lilacs from seed is easy, if you do it right, and it’s a great way to economically increase your lilac plantings.
Growing Lilacs From Seed
Lilacs belong to the olive family, or Family Oleaceae, and to the Genus Syringa.
The species name of the lilac plant is Syringa vulgaris, which is commonly known as lilac, or the common lilac.
There are many different lilac varieties which have been cultivated over time from seed.
The different hybrids have occurred either naturally, such as the Persian lilac, and as well through hybridizing efforts.
The plants are easily grown from seed, as long as the seeds are harvested at a viable stage.
Lilac seeds require stratification, and need to be prepared in a special way for planting, for best germination success.
The other thing to know about growing lilacs from seed, is that it will take some time before the brand new baby lilac plants will grow to be mature blooming lilac bushes. They are likely to bloom in 3 to 5 years, with proper care.
The new lilac bushes grown from seed will be new plants or hybrids.
If you are hoping to have a version of your favorite lilac bush, and save the seeds from that bush, the resulting plants may be very similar, however may also be very different, because they are hybrid plants.
How To Grow Lilacs From Seed
Harvesting The Seeds
If you have ever looked closely at a lilac bush after blooming, you may have discovered the lilac seed pods or seed capsules forming, where the flower once bloomed.
These pods will contain lilac seeds, and should be left to mature on the plant until they are brown and dry. The seed pods can usually be harvested in late summer or early fall.
If you wait until late fall, some of the seeds may have already been dispersed from the pods.
Saving lilac seeds is a fun activity, and should be done at the end of the season when those lilac seed pods are dry and are starting to open up. This is a good indicator of seed maturity, and you are likely to get viable seeds if you harvest at this time.
Once ready, cut the lilac seed pods from the bush with a sharp pair of pruners, and bring them inside.
Allow the pods to dry out some more if necessary. When you are ready to remove the seeds, you can open up the pods and extract the seeds from inside.
Where To Find Lilac Seeds
Lilac seeds are found within the lilac seed pod. There are generally one or two seeds, and sometimes up to four.
The seeds are a medium brown color, and are encased in a papery brown cover. This casing is oval in shape, and pointed at one end.
The seed covering measures approximately 1 cm in length. The seed inside is much smaller however, measuring only about 0.5 cm to 0.75 cm in length.
Once extracted from the seed pods, the seeds can be stored in a paper envelope. Place the seeds in a cool dry location until you are ready to prepare them for planting.
Make sure that you label the envelope with the storage date.
If you are planning to plant the seeds during the winter months, you may decide to skip this dry storage period. It will make more sense to just go straight to the preparation stage.
This involves cold moist storage, to help to stratify the seeds, which will help to prepare the seed coats for germination.
Preparing The Seeds For Planting- Stratification
To stratify the seeds, the lilac seeds will require a period of cold moist storage for at least 40 to 60 days.
This stratification or cold period will help to soften the hard seed coat. This will make it easier for the seeds to open up, when it is time to germinate.
If you are planning to winter sow the seeds, they will not require stratification in the fridge. That is because the seeds will receive this cold treatment naturally, when they are in their planting containers outside in the winter weather.
If you are planning to grow the lilac seed indoors however, you can stratify the seeds by placing them in the fridge.
To Stratify Lilac Seeds:
First place the seeds into a plastic baggie, along with some moist vermiculite. Tip the baggie slightly to remove any excess water, so that the seeds are not sitting in water.
Seal up the bag and store it in the fridge, for at least several months, or even longer. The seeds should remain in the fridge until you are ready to plant them.
When the seeds have been in the fridge for at least 40 to 60 days, they can be removed from the fridge.
These seeds are now ready for planting.
Once removed from the fridge the seeds may begin to sprout, even within a few days, if left in a warm location inside the baggie before planting. This is why I recommend to leave them in the fridge until you are ready to plant them.
This happened to my lilac seeds, and I was pleasantly surprised by the sprouting.
When the seeds were removed from the cool fridge temperatures, and exposed to the warmth, some, although not all, began to germinate.
The seeds were quickly planted up into containers, to grow indoors.
Planting Lilac Seeds
Lilac seeds can either be winter sown, or started in containers indoors in late winter, or early spring.
Starting Lilac Seeds Indoors
If you are planning to grow lilacs from seed indoors, remember to stratify the seeds first with a cold moist period in the fridge.
After the seeds have spent the appropriate time in the fridge, at least 40 to 60 days, remove them from the fridge for planting.
If you leave the bag without planting the seeds for a few days, you may find that some of the seeds may start to sprout. These small seedlings, as well as the unsprouted seeds, can be planted together in the planting container.
Planting The Seeds Indoors
- Choose a planting container with good drainage, such as a seed starter tray.
- Fill the container with a sterile soilless seed starting medium.
- Plant one lilac seed per cell, and gently cover with more of the mix, or some vermiculite. I often use vermiculite, as it helps to hold the moisture in the soil.
- Keep the soil moist while the lilac seeds are germinating, and do not allow the soil to dry out completely during this period. If the soil becomes dry, this can cause damage to the germinating seeds.
- Place the cell tray on a heat mat, until 60% of the tray has germinated.
- Then transfer the tray to a shelf with grow lights. The seedlings will require at least 14 hours of light daily for healthy growth.
- As the plants grow, the individual seedings can be removed from the seed trays, and potted up to 4-inch peat pots or plastic pots to allow for more growth.
- Grow the seedlings under the grow lights until they are ready to be transferred to an outside location when the weather warms up.
- Make sure to harden off the seedlings to help acclimatize the plants to their outdoor location.
How Long Does It Take For Lilac Seeds To Germinate?
Lilac seeds may germinate fairly quickly once removed from their cold moist storage.
Germination can occur from 7 to 30 days or more. The germination time will vary, depending on the seed.
Remember that these seeds are all unique hybrids with their own special characteristics, and they will not all germinate at the same time.
Seeds from the common lilac, or Syringa vulgaris, will likely reproduce plants very similar to the parent plant.
Winter Sowing Lilac Seeds
It is very easy to grow lilacs from seed using the winter sowing method.
Winter sown lilac seeds will not require stratification in the fridge, because the seeds will be naturally stratified by the winter sowing process.
The winter sowing process involves planting your seeds into a container, and placing the container outside during the winter months, to expose the seeds to cold temperatures and moisture.
As a result, the seeds become naturally stratified in this outdoor location.
Only certain types of seeds can tolerate this treatment, including hardy annual and perennial seeds, as well as those of certain trees and shrubs. Lilac seeds are included in this group.
Essentially, these seeds with very hard seed coats will tolerate and benefit from the winter sowing process.
I did another post on winter sowing in milk jugs, which explains the process in more detail.
To Winter Sow Lilac Seeds:
- Prepare a container for winter sowing. A recycled milk jug or juice jug, and even a large recycled pop bottle will do the trick.
- Cut the container in half, leaving a hinge to keep the top and bottom half just barely together.
- Make some drainage holes in the bottom, then fill with a soilless seed starting mix
- Plant the lilac seeds into the container, spacing them a couple of inches apart.
- Cover the seeds lightly with more of the mix, or alternatively with some vermiculite.
- Label the container with a permanent marker in several places, identifying the lilac seeds.
- Tape the container back together with duct tape.
- Remove the lid, so the rain and snow can enter the container.
- Place outside in a secure location, making sure that they container will not tip over by the winter winds.
- In spring when the timing is just right for your growing zone, the lilac seeds will germinate and begin to grow.
- The container will provide a greenhouse effect for the newly germinated plants, helping to keep them somewhat protected from the cold spring weather and occasional frosts.
- Keep an eye on the jug and make sure that the soil remains moist while the seeds are germinating.
- The young plants will become naturally hardened off in their outdoor location. Lift the lid off the jug to gradually expose the seedlings to the environment.
- Plant up into larger containers as the seedlings grow.
- Lilac seedlings are quite small during the first year of growth. The seedlings can spend some time outdoors, although do not have to be transplanted out at this time.
Planting Lilac Seedlings Into The Garden
Lilac seedlings can be transplanted out into the garden when they get a bit bigger, either in their first or second year of growth. This will allow them some time to grow in their seedling pots, and to establish their root system before planting out.
Seedlings which are not planted can be overwintered in a cool location, such as an unheated green house or garage. They will likely go dormant over the winter.
When ready to plant the lilac seedlings, the best time to plant out is in spring, when the soil is just beginning to warm up for the season.
This is a time of new growth, and the plants will have a chance to establish their roots in the garden, allowing for root growth during the entire growing season.
A spring planting will help to prevent heaving later in the season, when the ground freezes in winter in colder climates.
To Plant Lilac Seedlings:
- Make sure that the danger of all frost has passed before you transplant seedlings to their permanent location. It is important to know your last spring frost date for your usda plant hardiness zone.
- Choose a sunny location for best flowering, for when the plants become mature enough to flower.
- Plant into a prepared bed with fertile and well draining soil. Make sure that the root ball is at the same depth as was growing in the pot.
- Plant seedlings approximately 5 to 10 feet apart to accommodate plant size at maturity. Throw some bone meal into the planting hole, to get the plants off to a great start.
- Water in well after planting, and continue to provide watering until the plants become established in their new location.
Lilac Seedling Care
Once established, lilac seedlings will require little care. Lilacs are considered to be a low-maintenance plants.
- Lilacs grow best in usda plant hardiness zones 4 to 8.
- Lilac is an attractive deciduous shrub or small tree that will lose it’s foliage in the fall. The bare plants will survive very cold winters.
- The leaves will then regrow again in spring when the weather warms. Once the plants are mature enough to bloom, the blooms will follow in early summer, shortly after the leaves emerge in late spring.
- Lilacs do best if planted in a full sun location. Be aware as well of other structures in your planting location, such as trees, which may grow over time and shade out the plants.
- The shrubs will also tolerate some light shade, however will likely have less flowering in this location.
- Lilacs do best if they receive at least 6 to 8 hours of sunlight every day, with best results and best flowering in a full sun location.
- In very warm climates however, afternoon shade will provide some protection against the hot afternoon sun.
- Lilacs prefer a soil that is moist but not waterlogged.
- Watering the lilac plants once per week or during periods of drought will help to meet the moisture needs of the plants.
- Lilacs prefer a fertile and well-drained soil for best growth.
- Mulching over the soil with organic matter and leaf mulch will help to contribute to a fertile soil and improved soil quality over time.
Pests And Diseases
For the most part lilacs are hardy plants. However just like many other plant species, lilac does have it’s own susceptibility to certain pests and diseases.
Some of the common pest and disease problems that occur in lilacs include:
- Lilac borers, which can cause damage to the lilac leaves and stems.
- Leaf miners, which can cause damage to the foliage, creating dark patches on the leaves and distorted leaf growth.
- Scale insects, which suck moisture from the leaves and stems.
- Bacterial blight, which is a bacterial disease that causes brown spots and possible plant death.
- Powdery mildew, which coats the leaf surfaces with a white powdery coating.
To help prevent lilacs from developing disease and pest problems, keep the plants healthy by providing proper plant care. Regular watering and pruning, as well as selecting the right planting location, will go a long way to growing healthy lilac plants.
For example, powdery mildew is a common fungal disease for lilacs, which can cause unsightly foliage, generally at the end of the growing season. Good air circulation from pruning and proper spacing, as well as a full sun location, will help to prevent this problem.
Treat problems promptly if they occur, to prevent spread and promote lilac health.
How Long Does It Take To Grow Lilacs From Seed?
It does take a bit of time for each tiny lilac seedling to become a mature lilac plant, and large enough to produce flower buds.
The lilac seedlings may take 3 to 5 years before they have their first bloom. However, it is well with the wait.
Consider the amount of plantings that you can grow from seed, as well as the cost savings of growing your lilacs in this manner.
Not to mention the fun and excitement of planting the seeds, and then the anticipation of the first blooms, a few years later.
Frequently Asked Questions
When Should I Plant Lilac Seeds?
Winter sown lilac seeds can be planted and placed outside, at any time after the winter solstice. This is the first day of winter, and temperatures should stay cold until spring.
Indoor sown lilac seeds can be planted at any time after they have received the cold moist period for stratification.
If the seeds are started inside, the plants will need a little extra care. The new seedlings will require ongoing moisture and light, until they can be transplanted out or placed outside in spring.
What Is The Easiest Way To Propagate Lilacs?
I would have to say that one of the easiest ways to grow and propagate lilacs is from lilac roots or suckers, as compared to growing from lilac cuttings, or growing from seed.
Lilac shoots are often found growing close to an established lilac shrub, around the base of the plant. The root systems on the shoots are often quite mature and the stems are often woody.
This more mature state on the lilac shoots allows the new plants to mature fairly quickly. They will likely bloom much earlier, than lilacs grown from seed or stem cuttings.
This method of propagation will also create a clone of the parent plant, although stem cuttings does as well. This is a good thing if you are trying to multiply your favorite lilac bush.
Are Lilacs Difficult To Grow?
Lilac bushes are not difficult to grow, but rather these plants are very easy to grow and maintain.
You can grow lilacs from seed, cuttings or suckers. They can also be purchased as a potted lilac specimen from your local garden center, as many gardeners do.
For best blooms, make sure to plant in the right location, and to provide the best lilac care for your plants.
Lilacs can bring a lot of joy to anyone who grows them, or experiences the fragrant purple flowers in full bloom.
It is well worth having at least one lilac bush in the flower garden, if not many, to enjoy the amazing scent of lilacs every spring.
Growing lilacs from seed is a fun and easy way to propagate lilacs.
Depending on how many seeds you are able to harvest, you may end up having many small plants to enjoy.
You may even have enough to give some away, to the lilac lovers in your life.
It will take some time for the seedlings to mature to blooming sized plants. However it is certainly worth the effort in the end.
Consider harvesting and planting some lilac seeds next season. Then enjoy the results of your efforts, by producing many new and beautiful lilac plants.
Have you ever tried to grow lilacs from seed indoors? Be sure to leave a comment below to share your experience.