How to Propagate Lilacs? A Detailed Guide to Common Propagation Methods
Lilac propagation methods include division, layering, grafting, cuttings and seed sowing, among others. For lilacs, seed sowing and division are generally the most commonly used propagation methods.
Sowing is carried out in early April. First soak the seeds in hot water at 40-50°C for 1-2 hours, then remove them and mix them with sand at a ratio of one part seeds to two parts sand, place the mixture in a sunny spot, cover it with a straw bag or gunny bag, and water frequently to keep the straw bag or gunny bag moist. After about one week, the seeds will germinate, and then they can be sown.
Division can be carried out in March or November. Simply separate the clustered stems and branches growing from the base of the mother plant and transplant them elsewhere. Cuttings are best taken in autumn. Grafting mostly uses privet (Ligustrum) or water wax tree (Ligustrum obtusifolium) as rootstock, using the high grafting method, generally grafting at a height of 120-150 cm from the ground on the rootstock; the graft buds and scions should be selected from mother plants of superior varieties. Also be careful to prune off new shoots and buds emerging from the rootstock at any time, so as to avoid consuming nutrients and causing poor development of the graft buds and scions, with the rootstock overshadowing the scion. Layering is best done in February. When layering, thick branches should be treated by girdling. After the layer has taken root and survived, it can bloom in 2-3 years.
Lilacs are suitable for planting in the ground, and can also be grown in pots. When transplanting, keep as much soil around the roots as possible, as this makes it easier for them to survive.
Lilacs like sunlight, tolerate slight shade, prefer moisture, dislike waterlogging, are cold-hardy and drought-tolerant, and generally do not need much watering. They require fertile, well-drained sandy loam. If planted in a shaded environment, the branches will be thin, long and weak, the flower clusters short and loose, and the flowers lack luster. If planted in poor, thin soil, although they can still grow, the flowers will be fewer and the growth weak. Therefore, they should be planted in a sunny, fertile spot with deep soil.
When planting, bring a soil ball with the roots, and properly prune away some branches, then water thoroughly after planting. Afterwards, each spring when the weather is dry, water thoroughly once each when the buds begin to swell and before and after flowering. Lilacs do not like heavy fertilizing, and excessive fertilizer should be strictly avoided, otherwise it easily causes excessive vegetative growth and affects flowering. Generally, applying well-rotted compost once every year or every other year before winter is enough to replenish the nutrients in the soil. After the flowers fade, if you do not want to keep seeds, you can cut off the spent flowers together with the two buds below the flower cluster, and at the same time thin out some of the overly dense branches in the inner canopy, which helps ventilation and light penetration, keeps the tree shape attractive, and promotes the sprouting of new branches and the formation of flower buds.
After the leaves fall, the diseased, insect-damaged, dead and slender branches can be pruned away, and crossing branches, excessive vegetative shoots, overlapping branches and overly dense branches should be properly shortened, so that the branches are evenly distributed and the crown remains rounded, which benefits growth and flowering the following year. For lilacs planted in the ground, special attention should be paid to drainage and waterlogging prevention during the rainy season. Because if water accumulates for too long, they easily lose their leaves and die.
How to Grow Lilacs
1. Planting Method
We need to plant lilacs in a sunny spot with good ventilation and good light. We choose spring as the planting time, with a spacing of about 3 meters between each lilac, using plants that have been grown for more than 2 years, and dig the planting holes a bit larger, about 65-85 cm across and 55-65 cm deep
Apply 100 g of fully rotted organic fertilizer and 100-150 g of bone meal to each hole, mix thoroughly with the soil as a base fertilizer
2. Watering
Water promptly after planting, then water once every week afterwards. Watering varies according to different regions and climates. In North China, April to June is the season when lilacs grow vigorously and bloom, so water thoroughly 2-3 times a month. After July, when the rainy season begins, pay attention to drainage and waterlogging prevention. We should note that lilacs are not drought-tolerant, so we must water promptly.
3. Pruning
Pruning is generally carried out before the vigorous spring growth period, mainly pruning thin, weak and overly dense branches.
4. Fertilizing
Lilacs have low fertilizer requirements, and generally we choose not to fertilize, as too much fertilizer will affect the normal growth of lilacs. However, after flowering we can apply some phosphorus, potassium and nitrogen fertilizer to ensure the normal growth of the plant after the flowers fall.
How to Grow Lilacs
Lilac is the collective name for deciduous shrubs or small trees of the genus Syringa in the olive family (Oleaceae). Many of its species have flowers that are raw materials for extracting essential oils and blending fine perfumes, and its branches and leaves are lush and its flowers elegant in color and delicately fragrant, so it is widely cultivated in gardens for ornamental purposes and is a treasure of the garden. Now let us take a look at how to grow lilacs!
The Growth Habits of Lilacs
Lilacs love light and prefer warmth, moisture and plenty of sunshine. They tolerate slight shade; in shady or semi-shady spots they grow weakly and bloom sparsely. They have a certain degree of cold hardiness and strong drought tolerance. They are not demanding about soil and tolerate poor, thin soil, but prefer fertile, well-drained soil. They should not be planted in low-lying land, as water accumulation can cause disease and even death of the whole plant. Bare-root transplanting is done after leaf fall and before bud break, choosing a sunny spot with fertile soil and good drainage. They are mainly distributed in subtropical subalpine zones, on forest edges and under forests on slopes in the warm temperate to temperate zones, and in sunny shrublands of the cold temperate zone.
Lilac Propagation Methods
1. Grafting: Grafting is the main propagation method, and either bud grafting or scion grafting can be used. The rootstock is mostly European lilac (Syringa vulgaris) or small-leaf privet (Ligustrum quihoui). In North China, bud grafting is generally carried out from late June to mid-July. Select plump dormant buds on vigorous current-year branches as scions, and use the shield bud grafting method without wood, grafting onto the rootstock trunk at a height of 5-10 cm above the ground.
2. Sowing: This can be done in spring or autumn, either in pots indoors or in beds outdoors. In the north, spring sowing is preferable, carried out in late March in pots in a cold room, with the temperature maintained at 10-22°C; seedlings emerge in 14-25 days, with an emergence rate of 40-90%. If sowing outdoors in spring, it can be done from late March to early April. Before sowing, the seeds need to be stratified in sand at 0-7°C for about 2 months, and seedlings emerge half a month after sowing.
3. Cuttings: One month after flowering, select vigorous semi-lignified current-year branches as cuttings, about 15 cm long, treat them with a 50-100 PPM aqueous solution of indolebutyric acid for 15-18 hours, cover with plastic film after inserting, and they will root after 1 month, with a rooting rate of 80-90%. Lignified branches can also be taken as cuttings in autumn or winter, generally stored buried outdoors and inserted in the following spring.
How to Grow Lilacs
1. Planting: Lilacs should be planted in a sunny spot with loose, well-drained soil. Generally, bare-root planting is done in spring before the buds sprout, with a plant spacing of 3 meters. For 2-3 year old seedlings, the planting holes should be 70-80 cm across and 50-60 cm deep. Apply 100 g of fully rotted organic fertilizer and 100-150 g of bone meal to each hole, mix thoroughly with the soil as a base fertilizer.
2. Watering: After planting lilacs, water thoroughly, then water once every 10 days, and loosen the soil after each watering to conserve moisture. Irrigation can vary by region. In North China, April to June is the season when lilacs grow vigorously and bloom, so water thoroughly 2-3 times a month. After July, when the rainy season begins, pay attention to drainage and waterlogging prevention, and by mid-November, before winter sets in, water thoroughly.
3. Pruning: When planting large 3-4 year old lilac saplings, the above-ground branches and trunk should be heavily pruned, generally cutting the trunk at 30 cm above the ground; the second year they will produce abundant flowers. Pruning is carried out before the buds swell in spring, mainly removing thin, weak and overly dense branches while rationally retaining good renewal shoots. After flowering, remove the remaining flower clusters.
4. Fertilizing: Lilacs are generally not fertilized or are given only a small amount of fertilizer. Excessive fertilizing should be strictly avoided, otherwise it will cause excessive vegetative growth, thereby affecting flower bud formation and on the contrary reducing flowering. However, after flowering, some phosphorus, potassium and nitrogen fertilizer should be applied.
5. Pests and Diseases: Lilac diseases include bacterial or fungal diseases such as wilt disease, leaf blight and verticillium wilt, as well as diseases caused by viruses. These diseases generally occur during periods of high temperature and high humidity in summer. Insect pests include caterpillars, nettle grubs, leaf miners, large hornets and scale insects, among others, and attention should be paid to their control.