Getting it to bloom

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

Also called Toothwort, Two-leaved Toothwort, Crinkleroot, Pepper Root (Cardamine diphylla).

More about toothwort

About Toothwort

Cardamine diphylla · also called Toothwort, Two-leaved Toothwort · flowering

Toothwort is a delicate North American spring ephemeral in the mustard family, producing clusters of white to pale pink four-petalled flowers in early spring before tree canopy closes. The edible rhizomes have a peppery flavour. It naturalises easily in moist, deciduous woodland gardens and is one of the earliest native wildflowers to bloom each year.

Plant type: flowering

Watch for — Disappearing after flowering: Toothwort is a spring ephemeral that vanishes completely by late spring; this is entirely normal and not a sign of death or disease. Mark planting positions clearly to avoid accidentally digging up dormant rhizomes. Pair with later-emerging ferns or hostas to fill the gap.

The reasons toothwort isn't blooming

Almost every non-blooming toothwort 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 toothwort 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 toothwort to flower

Maximise sun. Give toothwort 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 toothwort and get the feeding right with the toothwort 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

Toothwort 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 toothwort care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Toothwort blooming — frequently asked questions

Why won't my toothwort flower?

Toothwort 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 toothwort bloom?

Give toothwort 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 toothwort normally bloom?