Getting it to bloom

Why won't my Clethra alnifolia 'Ruby Spice' bloom? (and how to make it flower)

Also called Ruby Spice summersweet, pink summersweet (Clethra alnifolia 'Ruby Spice').

More about clethra alnifolia 'ruby spice'

About Clethra alnifolia 'Ruby Spice'

Clethra alnifolia 'Ruby Spice' · also called Ruby Spice summersweet, pink summersweet · flowering

'Ruby Spice' is a deciduous, deep-pink-flowered selection of summersweet, a clump-forming native shrub prized for fragrant late-summer flower spikes that draw butterflies and bees. It thrives in moist, acidic soil and tolerates wet sites, part shade, and coastal salt. Pink bloom holds its colour better than older pink forms, fading to seed capsules.

Plant type: flowering

Watch for — Sparse bloom in deep shade: Too little light produces leggy growth and few flower spikes. Move to a brighter spot or thin overhead canopy for more sun.

The reasons clethra alnifolia 'ruby spice' isn't blooming

Almost every non-blooming clethra alnifolia 'ruby spice' 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 clethra alnifolia 'ruby spice' 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 clethra alnifolia 'ruby spice' to flower

Maximise sun. Give clethra alnifolia 'ruby spice' 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 clethra alnifolia 'ruby spice' and get the feeding right with the clethra alnifolia 'ruby spice' 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

Clethra alnifolia 'Ruby Spice' 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 clethra alnifolia 'ruby spice' care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Clethra alnifolia 'Ruby Spice' blooming — frequently asked questions

Why won't my clethra alnifolia 'ruby spice' flower?

Clethra alnifolia 'Ruby Spice' 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 clethra alnifolia 'ruby spice' bloom?

Give clethra alnifolia 'ruby spice' 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 clethra alnifolia 'ruby spice' normally bloom?