Three years ago I bought 3 small lilac shrubs which all had blooms on them. Last year only one had flowers. This year, again, only one (the same one) had flowers.
The shrubs are about 4′ high and I planted them in a sunny spot at our cottage near Lindsay.
Is it likely the two non-blooming lilacs will never bloom again, or is it too soon to give up on them?
Lilacs that don’t bloom can be very frustrating, but don’t give up on them just yet. Many experts have noted that lilacs need time to settle in after transplanting – sometimes a period of a few years – even if they were in bloom when you purchased them.
Here are a few other considerations.
Lilacs prefer fertile, well-drained soil that is neutral to alkaline (at a pH of 6.0 – 7.0). They will not bloom well if they are too wet, while at the same time requiring adequate moisture while buds are being set. If your cottage soil is poor, add organic material such as compost and shredded leaves to enrich it in the fall, and mulch in the spring. Lilacs also prefer full sun: they need at least 6 hours of sunshine daily in order to bloom. Lilacs bloom on old wood, and they set their buds in the summer. A late frost may damage the buds. If you plan to prune your lilacs, this must be done immediately after blooming: any later and you risk cutting off next year’s buds. Lilacs do not generally need supplemental fertilization. An excess of nitrogen in the soil nearby (if you have fertilized a lawn, for example) can inhibit flowering. Some experts suggest adding phosphorus in the form of bone meal to the soil around the lilacs.
If it is any comfort at all, you are not the only gardener who has wondered why their lilacs have bloomed erratically, or not at all. For their lovely fragrance alone, it is worth giving them another chance, and making sure that their growing conditions are the best you can offer.