Natureís most wonderful gift ĎThe Lilací

Presented here are a few doís and doníts on how to plant and care for your lilac.

Nature has tasked us to care for the lilac using four basic rules; provide good soil, good drainage, a minimum of 6 hours of direct sunlight and regular pruning. These factors will influence the quality and abundance of bloom, growth and vigor of the plant.

Extending the Bloom Season

It is possible to extend bloom season up 4-6 weeks by using lilacs from different species.

Hyacinthiflora, oblata---1 week before vulgaris

Vulgaris-----------------end of May in Montreal Quebec

Palibin, patula-----------beginning of June

Prestonia----------------mid June

Reticulata, pekinensis---end of June

Each specie and itís cultivars have their particular growth pattern and flower types. Fragrance varies from lilac to lilac.

Site Planning

The location where your lilacs will go and grow should be chosen with care. Avoid wind swept areas for the vulgaris type lilacs. They do not stand well to this situation. Lilacs generally require a 100 sq. ft. area per plant to properly grow to their potential. Crowding lilacs will only make them grow tall and flower at the top of the plant.


Lilacs require a minimum of 6 hours of direct sunlight per day to properly set flower buds. Less sun will diminish the amount of bloom.


Good drainage is essential for lilacs. They love water but do not wish to have their roots standing in it. They do not thrive in soggy soils. Poor drainage will result in dwarfed leaves and poor or little bloom. Plants will have little growth and slowly deteriorate until they die. This can take 4-5 years for the process to happen.

Heavy soils will always be poorly drained and it would be easier to create a mound about 3-4 wide and 12-15 inches above ground level. This mound would be best to be built with a porous material such as sand or a mixture of gravel and top soil.

When actually planting the lilac it is then that one should add the rich organic soil around the root system. But peat moss is the worst material to add to the planting mix, because it holds moisture and is acidic.

Pruning and fertilizer

The best fertilizer is one that has the second number in itís composition at least twice as high as the first. This will encourage bloom and not push the foliage too hard. An example of this would be 5-10-5. Fertilizers are different from each company so it is difficult to give an exact number. The fertilizer should be applied at the base of the plant in early spring to help the plant requirements for the year coming. Buds are set the year previous so the fertilizer will work on this yearís leaves but next yearís bloom. Mulching lilacs is also important. Using mulch helps reduce the heat stress lilacs have in the summer and will hold water better for them during the summer. Lilacs need regular watering during the summer also. If you see the leaves getting limp or droopy during summer months it is a sign that they need to be irrigated.

Pruning is not mandatory every year on main stems but cutting of faded blooms within a week of when they are spent will help the plant concentrate on preparing more flower buds and not seeds. As in any landscape plant, pruning should be done immediately after flower period. Once your lilacs have reached heights that no longer are pleasing to view or smell flowers, one should rejuvenate their plant over 3 years.

By cutting 1/3 of the main stems that are at least 1.5 inches in diameter down to 12-15" from the soil this will allow new shoots to grow again. Doing this over the three year period will allow the lilac to continue to flower and refresh itís look.

The most popular lilac question: Why doesnít my lilac flower?