Questions and Answers About Lilacs

The most often asked questions by lilac lovers are answered by Doc Lilac:

 

Q:  Why doesn’t my lilac bloom? A:  There are many reasons.  We list but a few here: Some varieties need to mature before blooming.  A few bloom when young, such as ‘Maiden’s Blush’ (Pink), ‘Mt. Baker’ (White), and ‘Lavender Lady.' The latter blooms in the south. Wrong fertilizer.  We suggest easy-to-use, long lasting fertilizer tablets such as 12-12-12 on young plants.  When older plants seem reluctant to bloom, use a flower or garden fertilizer such as 5-10-5 dry, super phosphate 0-15-0 dry, or triple super phosphate 0-45-0 dry.  Fertilize in the spring and fall.  Punch holes into ground around lilac and distribute one cup fertilizer over and into holes per small lilac.  Use 2 cups annually for lilacs over 5’ tall.  Lilacs also prefer a somewhat “limey soil.”  We sell tablets, fertilizer and lime. Transplanting set-back.  Often shocked by change in soil type, planting depths, improper watering, etc.  They take time to recover. Improper pruning.  Prune as soon after flowering as possible, allowing the plant 10-11 months to produce next years flower buds and to produce a bushier plant next year.  If you wait too long to prune you will cut off developing buds.  1/3 of the oldest stems should be cut to the ground periodically.  After flowering, cut off the brown, dead flowers or developing see-heads if you are fussy about appearance.  Otherwise it is not necessary.  Root pruning, with a sharp spade, may stimulate bloom. Over-watering in the fall.  Nature provides adequate moisture then.   Q:  How should I plant my lilac?  (Outdoors, of course) A:  Keep the pot, the plug or the ball of earth in burlap, moist until you are ready to plant.  Dig a hole 6” wider than the pot, plug or ball but not deeper.  Discard your soil if it is heavy clay, and replace with a looser, richer soil.  If sandy, mix with potting soil or compost and fill the hole ½ way up.  Tamp to firm, then water.  After water settles, finish filling hole and water again.  Cover the planting area with good mulch such as shredded bark.   (Be sure to label so you will always know the variety).  We sell labels.   Q:  How should I prune my lilacs? A:  Arm yourself with sharp pruners, shears, saws, or straight-edge spade.  See reference to pruning above.  Begin pruning when lilac reaches the desired height – usually 5-7’.  Remove all flowers plus 10-15” of stem, at bloom time or shortly thereafter.  This also prevents seed head development.   Q:  Where should I plant my lilac? A:  Lilacs prefer sun, but tolerate some shade.  Try not to plant in an acid soil, or add lime if you do.  See references to fertilizer above.  If area is wet, plant on a mound, or berm of improved soil to raise it above the moisture or heavy clay. Space 8-16’ apart for large lilacs; 4-6’ apart if you desire a hedge for privacy.