Getting it to bloom

Why won't my Sweet Autumn Clematis bloom? (and how to make it flower)

Also called Sweet Autumn Clematis, Japanese Clematis, Autumn Clematis (Clematis terniflora).

More about sweet autumn clematis

About Sweet Autumn Clematis

Clematis terniflora · also called Sweet Autumn Clematis, Japanese Clematis · flowering

Sweet Autumn Clematis (Clematis terniflora) is a vigorous deciduous climber native to Japan, producing clouds of small, sweetly fragrant white flowers from late summer through autumn, followed by silky seed heads. It grows rapidly and is considered invasive in parts of North America. All parts are toxic to pets if ingested.

Plant type: flowering

Watch for — Rampant growth: Can swamp neighbouring plants. Prune hard in late winter or early spring — it flowers on new season's growth so hard cutting does not reduce bloom.

The reasons sweet autumn clematis isn't blooming

Almost every non-blooming sweet autumn clematis 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 sweet autumn clematis 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 sweet autumn clematis to flower

Maximise sun. Give sweet autumn clematis 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 sweet autumn clematis and get the feeding right with the sweet autumn clematis 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

Sweet Autumn Clematis 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 sweet autumn clematis care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Sweet Autumn Clematis blooming — frequently asked questions

Why won't my sweet autumn clematis flower?

Sweet Autumn Clematis 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 sweet autumn clematis bloom?

Give sweet autumn clematis 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 sweet autumn clematis normally bloom?