Getting it to bloom

Why won't my Cardinal climber bloom? (and how to make it flower)

Also called Cardinal climber, Hearts and honey vine (Ipomoea x multifida).

More about cardinal climber

About Cardinal climber

Ipomoea x multifida · also called Cardinal climber, Hearts and honey vine · flowering

Cardinal climber is a fast-growing annual vine — a hybrid of Ipomoea quamoclit and I. coccinea — with finely dissected, feathery foliage and vivid crimson trumpet flowers that are irresistible to hummingbirds. Grow in full sun on a trellis. Performs best in warm summers with consistent moisture. Seeds are toxic; handle with care.

Plant type: flowering

Watch for — Few flowers despite healthy growth: Excess nitrogen or too-rich soil diverts energy to foliage. Switch to a phosphorus-higher fertiliser and ensure the plant receives full sun. Consistent but not excessive watering also helps.

The reasons cardinal climber isn't blooming

Almost every non-blooming cardinal climber 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 cardinal climber 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 cardinal climber to flower

Maximise sun. Give cardinal climber 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 cardinal climber and get the feeding right with the cardinal climber 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

Cardinal climber 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 cardinal climber care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Cardinal climber blooming — frequently asked questions

Why won't my cardinal climber flower?

Cardinal climber 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 cardinal climber bloom?

Give cardinal climber 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 cardinal climber normally bloom?