Getting it to bloom

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

Also called trumpet vine, trumpet creeper, cow-itch vine (Campsis radicans).

More about campsis radicans

About Campsis radicans

Campsis radicans · also called trumpet vine, trumpet creeper · flowering

A vigorous deciduous climber native to the southeastern US, prized for clusters of large orange-to-scarlet trumpet flowers from summer to autumn that draw hummingbirds and bees. It self-clings by aerial rootlets, scaling walls and fences fast. Robust and hardy, it can be invasive and suckering, so plant where its rampant spread can be controlled.

Plant type: flowering

Watch for — Few or no flowers: Most often from too much shade, excess nitrogen, or impatience — young plants can take 2-3 years to bloom. Site in full sun and avoid rich feeding.

The reasons campsis radicans isn't blooming

Almost every non-blooming campsis radicans 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 campsis radicans 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 campsis radicans to flower

Maximise sun. Give campsis radicans 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 campsis radicans and get the feeding right with the campsis radicans 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

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

Campsis radicans blooming — frequently asked questions

Why won't my campsis radicans flower?

Campsis radicans 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 campsis radicans bloom?

Give campsis radicans 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 campsis radicans normally bloom?