Completely different in form, the ivory silk lilac stands as a single-trunked small tree or large shrub with white flowers that have very little fragrance which bloom in the summer months. The cultivar lends itself to uses that the straight species is lacking. For this reason, it deserves to be considered when you need a showy ornamental tree capable of adapting to a few uses in a landscape design.
Light
In order to guarantee you get the most abundant amount of blooms, you will want to put your Ivory Silk Lilac in a location that gets full sun. Putting it in a location with part sun or shade will give you a noticeable drop off in flowers, which is the main appeal of the tree, so plan ahead and pick the best spot before planting. If it is in a sunny spot, your tree will explode with huge white clusters of blooms and you will not regret the extra effort of scouting the perfect spot.
Soil
One of the great things about the ivory silk lilac is that it is capable of growing in some pretty terrible soil conditions. You do not want to aim to plant it in bad soil but it can be planted in adverse conditions like tree pits, as street trees, or to line a driveway, where soil might be rocky or compressed. The ideal soil would be an average soil rich in organics that is well-draining and is neutral to slightly alkaline.
Water
For such an ornamental tree you would think that the Ivory Silk Lilac would be a water hog but it actually is somewhat drought tolerant. In extremely dry weather it would be best to give some supplemental watering but unless you notice the tree suffering it can do well on its own on warm summer days. You will need to provide it with water for the first two seasons while it is establishing a good strong root system. To give your watering a boost and to help conserve water you should apply a layer of mulch around the base of the tree out to the dripline. After you apply your mulch you will want to water your newly planted tree every week at a rate of one gallon per trunk diameter at chest height. You should do this weekly for the first two years and then let nature take care of the rest.
Temperature and Humidity
Sadly one of the few drawbacks of the Ivory Silk Lilac is its somewhat narrow habitable range. When it comes to temperature extremes, it is not very hardy and will only thrive in the limited USDA range of 3 through 7.
Fertilizer
Applying a yearly feeding of a general slow-release fertilizer formulated for ornamental flowering trees is recommended to help keep your Ivory Silk Lilac in tip-top shape. Applying the fertilizer lightly in the spring once frost has passed with extended-release formulation should keep your tree happy and encourage an abundant amount of blooms and foliage.
Types of Ivory Silk Lilac Trees
‘Ivory Silk’ is just one unique cultivar of Syringa reticulata. Many cultivars of the species look nothing like ‘Ivory Silk’ with completely different traits. Cultivars are cultivated varieties specifically selected by those in the nursery trade to highlight specific traits. If you love lilacs, but ‘Ivory Silk’ is not exactly what you are looking for (it is not like most lilacs), this list of lilac cultivars might help:
Syringa reticulata’ Chantilly Lace’ is a multi-stemmed cultivar with creamy yellow variegated leaves.Syringa reticulata ‘Summer Snow’ is a small cultivar with a compact form with very large flower clusters.Syringa reticulata ‘Sum Dak’ is an upright cultivar similar to ‘Ivory Snow’ but faster-growing with an even more erect form.Syringa reticulata ‘Summer Storm’ is a cultivar known for its faster than normal growth and is thought to be slightly more hardy in colder weather.
Pruning
After a few years, you may notice that your Ivory Silk Lilac might start producing fewer blooms. This is not too of concern and is completely normal. You will want to do some maintenance pruning to encourage new growth which will, in turn, rejuvenate your tree and force it to produce more blooms. If your tree is small enough to do this safely from the ground with hand clippers, saw or lopers trim away one-third of your tree’s largest stems. This step can be performed annually while the tree is dormant before new growth begins to appear.
Common Pests and Plant Diseases
Luckily the Ivory Silk Lilac does not get attacked by many insects if placed in the proper setting. One problem that you may encounter is borers which can cause some nuisance issues but nothing too serious. Prevent infestation by keeping your tree happy with water when stressed in overly dry weather and regular fertilizing. If borers attack, remove the infested, damaged branches and dispose of them responsibly. Normally your tree will be disease-free if you maintain regular chores such as watering and fertilizing. Unfortunately, several diseases can affect the species regionally. Bacterial blight is always a concern on white-flowered cultivars. Blight is especially prevalent during wet weather and when over-fertilizing with nitrogen-heavy fertilizers. Verticillium wilt is a concern, but proper fertilizing and good tool cleanliness are the best ways to avoid this incurable malady.