Getting it to bloom

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

Also called Tuberous Cranesbill, Tuberous-Rooted Cranesbill (Geranium tuberosum).

More about tuberous cranesbill

About Tuberous Cranesbill

Geranium tuberosum · also called Tuberous Cranesbill, Tuberous-Rooted Cranesbill · flowering

Geranium tuberosum is a spring-flowering cranesbill native to the Mediterranean basin east to Iran, growing from small underground tubers. It behaves like a spring ephemeral: finely divided foliage emerges in late winter, lilac-pink veined flowers appear in spring, and the whole plant retreats into summer dormancy by early summer. The most important care fact is to provide a sunny, sharply drained position and allow the soil to dry out completely in summer — wet summer soils rot the tubers. ASPCA's toxic 'Geranium' entry refers to Pelargonium; true Geranium cranesbills are not individually listed as toxic, but ASPCA does not confirm them as non-toxic either, so treat with caution around pets.

Plant type: flowering

The reasons tuberous cranesbill isn't blooming

Almost every non-blooming tuberous cranesbill 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 tuberous cranesbill 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 tuberous cranesbill to flower

Maximise sun. Give tuberous cranesbill 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 tuberous cranesbill and get the feeding right with the tuberous cranesbill 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

Tuberous Cranesbill 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 tuberous cranesbill care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Tuberous Cranesbill blooming — frequently asked questions

Why won't my tuberous cranesbill flower?

Tuberous Cranesbill 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 tuberous cranesbill bloom?

Give tuberous cranesbill 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 tuberous cranesbill normally bloom?