Getting it to bloom

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

Also called Dusky cranesbill, Mourning widow geranium, Black widow geranium (Geranium phaeum).

More about geranium phaeum

About Geranium phaeum

Geranium phaeum · also called Dusky cranesbill, Mourning widow geranium · flowering

Geranium phaeum, the dusky cranesbill or mourning widow, is a clump-forming woodland perennial grown for its small, reflexed flowers in deep maroon-purple to near-black, held on slender stems above soft, often blotched leaves in late spring and early summer. One of the best hardy geraniums for shade and dry shade, it self-seeds gently and naturalises beautifully beneath trees and shrubs.

Plant type: flowering

Watch for — Tatty post-flowering foliage: Leaves look ragged after blooming. Shear the whole plant to the ground after flowering for a fresh mound of new foliage.

The reasons geranium phaeum isn't blooming

Almost every non-blooming geranium phaeum 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 geranium phaeum 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 geranium phaeum to flower

Maximise sun. Give geranium phaeum 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 geranium phaeum and get the feeding right with the geranium phaeum 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

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

Geranium phaeum blooming — frequently asked questions

Why won't my geranium phaeum flower?

Geranium phaeum 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 geranium phaeum bloom?

Give geranium phaeum 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 geranium phaeum normally bloom?