Getting it to bloom

Why won't my Black Calla Lily bloom? (and how to make it flower)

Also called Black Calla Lily, Black Star Calla (Zantedeschia 'Black Star').

More about black calla lily

About Black Calla Lily

Zantedeschia 'Black Star' · also called Black Calla Lily, Black Star Calla · flowering

Zantedeschia 'Black Star' is a striking hybrid calla lily producing intensely deep maroon-black spathes on tall stems above lush, dark green, sometimes spotted foliage. A highly sought-after cut flower and container plant, it thrives in full sun with consistent moisture during growth and a dry winter dormancy. All parts are toxic to cats, dogs, and humans due to calcium oxalate raphides.

Plant type: flowering

Watch for — Aphids on new growth: Aphids cluster on emerging shoots and flower buds in spring. Blast off with a strong jet of water, or apply insecticidal soap. Ants tending aphid colonies on outdoor plants indicate an infestation — use a sticky barrier on pot legs.

The reasons black calla lily isn't blooming

Almost every non-blooming black calla lily 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 black calla lily 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 black calla lily to flower

Maximise sun. Give black calla lily 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 black calla lily and get the feeding right with the black calla lily 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

Black Calla Lily 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 black calla lily care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Black Calla Lily blooming — frequently asked questions

Why won't my black calla lily flower?

Black Calla Lily 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 black calla lily bloom?

Give black calla lily 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 black calla lily normally bloom?