Getting it to bloom

Why won't my Lily of the valley bloom? (and how to make it flower)

Also called May lily, May bells, our lady's tears (Convallaria majalis).

About Lily of the valley

Convallaria majalis · also called May lily, May bells · flowering

Lily of the valley is a shade-loving perennial with broad green leaves and tiny fragrant white bells in late spring. Spreads by rhizome to make ground cover. Severely toxic to pets and people — every part contains cardiac glycosides.

Convallaria majalis is a rhizomatous herbaceous perennial of Europe and Central Asia (naturalized in temperate North America and invasive in parts of the northern US), forming a low 8–12 in groundcover of arching white bells.

Plant type: flowering

Watch for — Sparse flowers: Overcrowded — divide every 3-4 years.

Sources: missouribotanicalgarden.org, pmc.ncbi.nlm.nih.gov

The reasons lily of the valley isn't blooming

Almost every non-blooming lily of the valley traces back to one of these, roughly in order of how common they are:

Bulbs were not chilled long or cold enough (a problem in mild winters or with un-chilled forced bulbs).
The winter was too mild or the plant too sheltered to bank enough chill hours.
Foliage was cut down too early last year, so the bulb could not recharge for this year’s bloom.
Too little sun during the growing season to build the reserves the flower needs.
Excess nitrogen feed driving leaf at the expense of flower.

Skipping the cold period (or buying un-chilled bulbs in a mild climate). Without real vernalisation there are no flowers.

The fix — how to get lily of the valley to flower

Let it get genuinely cold. Leave lily of the valley outdoors (or in an unheated, cold spot) through winter — do not mulch heavily or shelter it from the cold it needs.
Chill the bulbs properly. Use pre-chilled bulbs, or give 12-16 weeks of cold (around 4-9 °C / 40-48 °F) before planting in mild climates.
Feed the foliage, then leave it. Let leaves grow and feed the plant after flowering; never cut foliage down until it yellows naturally.
Be patient after any move. Expect a settling year (or two to three for peony) with few or no flowers after planting or division — this is normal, not failure.

Light and feeding do most of the heavy lifting here. Dial in the spot with the light guide for lily of the valley and get the feeding right with the lily of the valley 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

Lily of the valley flowers in its season (typically spring for chilled bulbs) once the cold requirement is met, then dies back to recharge for next year.

Post-bloom care so it flowers again

Let the foliage die back fully before tidying — it is recharging the bulb. A light feed after flowering supports next year's display.

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

Lily of the valley blooming — frequently asked questions

Why won't my lily of the valley flower?

Lily of the valley needs a real cold period (vernalisation) to flower — the winter chill is the signal that ripens the bud inside the bulb or crown. The most common reason it is not happening: Bulbs were not chilled long or cold enough (a problem in mild winters or with un-chilled forced bulbs).

How do I make lily of the valley bloom?

Leave lily of the valley outdoors (or in an unheated, cold spot) through winter — do not mulch heavily or shelter it from the cold it needs. Use pre-chilled bulbs, or give 12-16 weeks of cold (around 4-9 °C / 40-48 °F) before planting in mild climates.

When does lily of the valley normally bloom?