Getting it to bloom

Why won't my Thorn Apple bloom? (and how to make it flower)

Also called Thorn Apple, Jimsonweed, Devil's Snare, Moonflower (Datura stramonium).

More about thorn apple

About Thorn Apple

Datura stramonium · also called Thorn Apple, Jimsonweed · flowering

Datura stramonium is a robust annual weed originating in central America and now naturalised globally in disturbed ground, roadsides, and waste places. It grows rapidly in full sun with any free-draining soil, producing large white to pale purple trumpet flowers and spiny seedpods. The single most important fact is that every part of the plant — seeds, leaves, roots, flowers — contains high concentrations of tropane alkaloids and is dangerously toxic to humans, pets, and livestock. This plant is highly toxic to dogs and cats.

Plant type: flowering

Watch for — Botrytis (grey mould): In cool, wet summers, Botrytis cinerea infects dying flowers and spreads to stems; remove dead flowers promptly and improve air circulation.

The reasons thorn apple isn't blooming

Almost every non-blooming thorn apple 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 thorn apple 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 thorn apple to flower

Maximise sun. Give thorn apple 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 thorn apple and get the feeding right with the thorn apple 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

Thorn Apple 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 thorn apple care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Thorn Apple blooming — frequently asked questions

Why won't my thorn apple flower?

Thorn Apple 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 thorn apple bloom?

Give thorn apple 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 thorn apple normally bloom?