How to care for your lilac shrubs

Last week’s column provided an introduction to lilacs. Now that you have decided to plant some lilacs here are some tips to follow to help you get the best results. Lilacs need three things to grow and bloom well: sun, soil that’s not soggy and space.
Step 1 – Good Planning
For the best blooms, plant lilacs in an area that receives at least six hours of direct sunlight daily. Lilacs should be planted on a slightly raised area or on level ground. Lilacs are also a good choice for the side of hills or slopes. Water newly planted shrubs at least once a week during dry periods, for the first year. Special Tip: Avoid planting lilacs in a sunken area that remains wet for long periods of time as they will get waterlogged and die.
Step 2 – Proper Spacing
Although this tip may seem like overkill, when you’ve just gotten a very small little shrub home from the nursery, but most lilacs spread out to about eight feet and need to be planted at least eight feet apart. Plenty of space will mean your bushes get good airflow all around them which prevents powdery mildew. Providing ample space also ensures that the roots and crown develop fully and evenly, allowing for a healthier shrub overall.
Step 3 – Feed them Appropriately
Use a high phosphorus (middle number) fertilizer in the early spring prior to blossoming to promote large richly coloured blooms. Bonemeal is a good choice for this but other fertilizers with a high phosphorus number will also work. Fertilize again after blooming with a general purpose fertilizer (all three numbers are relatively even). Special Tip: Do not over fertilize as more is not better and never use a fertilizer with a high first number (N-nitrogen) as you will only get a lot of leaves.
Step 4 – Allowing the Shrub to Establish in its First Few Years
Lilacs need a couple of years to establish themselves, so in order to allow them to develop a better root system perform the following:
In the first year of flowering, remove all flower heads before they develop into flowers.
In the second year of flowering, remove three quarters of all the flower heads before they develop into flowers.
Remember for the long-term, this is worth the sacrifice of two years without blooms.
Step 5 – Keeping Competition at Bay
One of lilacs worst enemies is competition from weeds. Always cut a circle of sod away from the trunk and apply a mulch to retain moisture and prevent weeds. This also keeps the lawn mower from inadvertently getting too close.
Step 6 – Maintaining the Shrub
If you need to do any pruning, do so immediately after blooming. Even though you can’t see them yet, your lilac goes right to work producing next year’s flower buds. If you wait too long before trimming off dead blooms, you may end up cutting of the next year’s blooms in the process. Selectively remove branches from the interior of the bush to increase air circulation and maintain the health of your lilac. Choose the dead or dying branches first then the interior branches that have a flimsy look. Leave several of the healthiest young branches to replace the older wood you have cut as they will produce blooms of their own in about three years. Special Tip: Maintain a rounded shape to your lilacs by pruning stray limbs. Be careful here and keep the overall shape in mind. A lilac bush should have uniform shape and should not look like a long trunk with a puff of leaves at the top.
Step 7 – Keeping the Flowers Coming
Every year when the flowers begin to fade, remove them from the shrub as this will stop the plant putting unnecessary effort into producing seed. This must be done as soon as flowering stops.
As with all trees and shrubs, suckers at the trunk steal valuable energy away from the predominant part of the tree. You want to remove suckers or any young shoots that begin to grow from the base of the tree from all trees and shrubs but especially lilacs, other flowering shrubs and fruit trees. You want the energy being directed to the production of your flowers. This task may be ongoing throughout the growing season.
Following these steps will ensure that you are well on your way to enjoying your own lilacs to their fullest each season.