Getting it to bloom

Why won't my Madame Lemoine Lilac bloom? (and how to make it flower)

Also called Common Lilac, Madame Lemoine Lilac, French Lilac (Syringa vulgaris 'Madame Lemoine').

More about madame lemoine lilac

About Madame Lemoine Lilac

Syringa vulgaris 'Madame Lemoine' · also called Common Lilac, Madame Lemoine Lilac · flowering

Madame Lemoine is a classic double-white French lilac producing intensely fragrant creamy-white panicles in mid to late spring. It is a large, long-lived deciduous shrub best grown in full sun with good air circulation. Syringa is not listed as toxic by the ASPCA.

Plant type: flowering

Watch for — Failure to flower: Most often caused by incorrect pruning (removing flower buds on old wood) or insufficient chilling hours in mild winters; avoid pruning except immediately after flowering.

The reasons madame lemoine lilac isn't blooming

Almost every non-blooming madame lemoine lilac traces back to one of these, roughly in order of how common they are:

Too little sun — most of these need full sun (or very bright light) to flower well; shade gives leaves, not blooms.
Too much nitrogen feed, driving lush foliage at the expense of flowers (very common with general or lawn feeds).
The plant has not been deadheaded, so it stops flowering once it sets seed.
Irregular watering — drought or waterlogging at the budding stage makes buds abort.
It is still too young or was checked by a transplant and is rebuilding before flowering.

Feeding madame lemoine lilac a high-nitrogen general feed and growing it in too little sun — you get a big leafy plant and almost no flowers.

The fix — how to get madame lemoine lilac to flower

Maximise sun. Give madame lemoine lilac the sunniest spot you have — for most bedding and fruiting plants, more direct light directly means more flowers.
Switch the feed. Move off high-nitrogen feeds and use a higher-potassium "bloom" or tomato-type feed as it comes into flower.
Deadhead regularly. Remove spent flowers often to keep it producing more rather than stopping to set seed.
Water consistently. Keep moisture even through budding and flowering — drought-then-flood swings make buds drop.

Light and feeding do most of the heavy lifting here. Dial in the spot with the light guide for madame lemoine lilac and get the feeding right with the madame lemoine lilac fertilising schedule — the wrong feed (too much nitrogen) is one of the most common silent reasons a healthy plant makes leaves instead of flowers.

Bloom season and what to expect

Madame Lemoine Lilac flowers across its growing season (mostly summer) and, kept fed and deadheaded, can bloom for many weeks or right up to frost.

Post-bloom care so it flowers again

Deadhead, keep feeding lightly, and many will rebloom; collect seed from the best plants at the end of the season if you want to grow them again.

For everything else this plant needs day to day, see the full madame lemoine lilac care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Madame Lemoine Lilac blooming — frequently asked questions

Why won't my madame lemoine lilac flower?

Madame Lemoine Lilac blooms on the season's growth given enough sun, warmth and the right feed — there is no cold or photoperiod trick, just good growing conditions and a bloom-leaning feed. The most common reason it is not happening: Too little sun — most of these need full sun (or very bright light) to flower well; shade gives leaves, not blooms.

How do I make madame lemoine lilac bloom?

Give madame lemoine lilac the sunniest spot you have — for most bedding and fruiting plants, more direct light directly means more flowers. Move off high-nitrogen feeds and use a higher-potassium "bloom" or tomato-type feed as it comes into flower.

When does madame lemoine lilac normally bloom?