Free Lilacs for Life!
Would you like a free and unlimited numbers of lilacs? Anyone can make more of them by rooting short cuttings of the branches of mother plants.
The best lilacs are taken from named cultivars, or “cultivated varieties.” Here’s a summary of how to do it, with detailed information and pictures following:
1. Choose a lilac cultivar with no active patent.
2. Prepare a pot or container with a plastic humidity cover.
3. Add rooting medium of coarse sand, with or without peat, potting soil, or perlite.
4. Take 6-inch cuttings from the ends of new green softwood growth in spring.
5. Remove all but the top 4 leaves and cut the base through a leaf bud node.
6. Dip in IBA rooting hormone and stick 2 inches apart in the pot.
7. Mist inside the plastic covering of the pot twice daily; keep the soil moist.
Legal Cuttings
Cuttings can be taken from any lilac without an active patent. Patents apply to a few generically named cultivars for a limited number of years (20 years in the USA); after that, anyone can freely propagate that cultivar. Look for “USPP No. #” or “PPAF” after a name. USA patents can be found at http://patft.uspto.gov/.
Trademarks (™) or registered trademarks (®) do not apply to a specific cultivar, but to a name used by a specific business. These are indefinitely renewable (unlike patents). This means you can take cuttings of the cultivar, but you can’t use the trademark name, only the generic cultivar name.
For instance, the common lilac S. vulgaris ‘Monore’ is the generic cultivar name, while BLUE SKIES® is its registered trademark name. It’s patent expired in 2009 so you can take cuttings of this plant and label or sell it as ‘Monore’, but you couldn’t label or sell it as BLUE SKIES® since Monrovia Nursery has the exclusive right to use that trademarked name.
Covered Containers
For a small number of cuttings, use a flowerpot or plastic container with drainage holes. You can put 6 cuttings in a 6-inch pot, with at least 3–4 inches of rooting medium for sticking the cuttings. Then place them and the pot inside a plastic bag (for misting) with a twist tie at the top. You could also use similar covers like a milk carton with the bottom cut out, or plastic cups.
Rooting Medium
Use a soilless mix. This reduces the chance of disease. You need good drainage and aeration for lilacs with no fertilizer. Don’t use vermiculite as it compacts and holds too much moisture. Possible mixes include the following:
- Coarse or paver’s sand alone. Do not use play sand, which is too fine and may have salt in it.
- 1:1 coarse sand and either peat, potting soil, or perlite.
Heating and Light
Heat is not necessary but speeds the process. A heat mat can be used for 70–90°F bottom temperatures until rooting occurs. Bright indirect light with no direct sunlight is required. Good places are near a window or on a covered patio. Plant lights are not advisable.
Cutting Type and Timing
Lilac cuttings root most easily at the green softwood stage. This means they are just soft and thick enough to bend and snap.
Cuttings are best taken in early spring after buds form and up until 2 weeks after flowering. In most areas, this will be from mid-April to mid-June.
Cutting Selection
Cuttings should be taken from the current season’s new growth with no buds or flowers. Collect cuttings in the morning, wrap them in a damp paper towel and place in a plastic bag. Keep the fresh cuttings cool and out of the sun, using a cooler if needed. Plant them the same day and never crush or squeeze the stem.
Cutting Preparation
Cutting lengths should be 4–6 inches. Leaves should be stripped from the lower half of the cutting to reduce water loss. Leave only two to four paired leaves. Cut them in half horizontally if they are large. If all the leaves drop before rooting occurs, it will need to be discarded. Cut the base of the cutting’s stem just below the leaf bud. Wounding or crushing the stem is not necessary and may be harmful.
Rooting Hormone Treatment
Plants have natural hormones that promote rooting. A synthetic hormone called IBA can do the same thing. For lilacs, which are hard to root, a moderately strong concentration between 0.3–0.8% IBA in a liquid or powder form is used.
Pour the powder or liquid from its original container into a separate clean container to avoid contamination. Dip the bottom 1–2 inches of the cutting in the liquid, or wet it and dip in the powder, shaking off any excess.
Sticking the Cuttings in the Rooting Medium
Cuttings (coated with IBA) should be stuck in the rooting medium as soon as possible. Use a dibble (like a pencil or clean stick) slightly larger than the cuttings’ diameter to make a hole so the rooting powder is not knocked off on cutting insertion.
Insert cuttings 1.5–2 inches deep, maintaining proper vertical orientation. Tamp down the rooting medium to hold the cuttings firmly in place and then water and mist them. Space the cuttings about 2–3 inches apart, so their leaves don’t touch anything.
Misting and Watering
Since they have no roots, cuttings get their water (and food) from the remaining leaves. The leaves get water from the surrounding air or leaf surface, hence the need for misting and high humidity. Cover the cuttings with a plastic bag or a milk carton with the bottom cut out. Mist with a misting bottle several times daily for 4–12 weeks until rooted, keeping the inside moist with condensation and the soil moist but not soggy.
Rooting Time and Checking for Roots
Fresh cuttings may look wilted the first week but should perk up after that. Common lilacs take twice as long to root as late lilacs. Expect common lilacs to root over 2–3 months, and late lilacs to root over 4–6 weeks. At those times, pull gently on the cutting’s stem; if rooted, you will have complete resistance and it can then be dug out.
Remove any molded or fallen leaves, dead cuttings, or cuttings with no leaves. Cuttings with no leaves will not root. After successful rooting, remove the humidity cover or transplant the cutting.
Post-Rooting Care
After rooting, transplant into small 3–4-inch diameter quart pots. Fill the pots with ½ potting soil and ½ coarse sand and insert the roots 2 inches deep. Long-acting fertilizer may be added. Stop misting and only water the rooting medium when it dries out.
Place the pots in bright indirect light or dappled shade until new leaves form (a great sign), roots come out of drainage holes, or cooler temperatures arrive in the fall. Then transplant into one-gallon, 6-inch wide by 6-inch deep containers and place in the sun. Late lilacs can usually be transplanted and put in the sun sooner than common lilacs.
For winter, place these lilac containers in a protected area, such as against a building or inside an unheated space. They will survive occasional temperatures to -10°F with no problem but will still need watering once per month.
In spring, after the first season of growth, prune them back to 2–4 inches to induce branching. They can then be planted with good protection from animals, or held another year or two, planting before they reach 3–4 feet in height. But don’t be fooled! They won’t flower indoors; they can be started indoors, but must have full sun and at least 2 weeks of freezing weather in winter to thrive and flower with that wonderful fragrance.
Enjoy your free lilacs!
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Dr. DeBard is a retired Professor Emeritus of Emergency Medicine.
He is the Registrar for the International Register and Checklist of Cultivar Names in the Genus Syringa L. (Oleaceae), and a member of the Board of Directors of The International Lilac Society.
(www.internationallilacsociety.org).
