Getting it to bloom

Why won't my Parthenocissus tricuspidata bloom? (and how to make it flower)

Also called Boston ivy, Japanese creeper, grape ivy (Parthenocissus tricuspidata).

More about parthenocissus tricuspidata

About Parthenocissus tricuspidata

Parthenocissus tricuspidata · also called Boston ivy, Japanese creeper · flowering

Parthenocissus tricuspidata, or Boston ivy, is a vigorous deciduous self-clinging climber famous for glossy three-lobed leaves that blaze crimson and scarlet in autumn. It clings to walls by adhesive sucker pads, needing no support, and tolerates sun or shade. The greenish summer flowers are insignificant; black-blue berries follow. Foliage and berries are toxic to pets.

Plant type: flowering

The reasons parthenocissus tricuspidata isn't blooming

Almost every non-blooming parthenocissus tricuspidata 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 parthenocissus tricuspidata 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 parthenocissus tricuspidata to flower

Maximise sun. Give parthenocissus tricuspidata 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 parthenocissus tricuspidata and get the feeding right with the parthenocissus tricuspidata 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

Parthenocissus tricuspidata 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 parthenocissus tricuspidata care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Parthenocissus tricuspidata blooming — frequently asked questions

Why won't my parthenocissus tricuspidata flower?

Parthenocissus tricuspidata 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 parthenocissus tricuspidata bloom?

Give parthenocissus tricuspidata 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 parthenocissus tricuspidata normally bloom?