Getting it to bloom

Why won't my Curly Pondweed bloom? (and how to make it flower)

Also called Curly Pondweed, Crisped Pondweed, Curly-leaf Pondweed (Potamogeton crispus).

More about curly pondweed

About Curly Pondweed

Potamogeton crispus · also called Curly Pondweed, Crisped Pondweed · flowering

Curly Pondweed is a submerged aquatic plant recognized by its distinctive wavy, serrated, bronze-green leaves that resemble lasagne pasta ribbons. Native to Eurasia, it is one of the few aquatic plants that grows actively in winter and early spring when water temperatures are low, making it a valuable early-season oxygenator and invertebrate habitat in wildlife ponds.

Plant type: flowering

Watch for — Summer dieback and turion formation: Goes dormant in summer heat (above 22–25°C), dying back and forming turions (vegetative resting buds) that sink to the sediment. This is natural behaviour; plants regrow in autumn when water cools. Do not discard apparently dead plants.

The reasons curly pondweed isn't blooming

Almost every non-blooming curly pondweed 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 curly pondweed 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 curly pondweed to flower

Maximise sun. Give curly pondweed 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 curly pondweed and get the feeding right with the curly pondweed 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

Curly Pondweed 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 curly pondweed care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Curly Pondweed blooming — frequently asked questions

Why won't my curly pondweed flower?

Curly Pondweed 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 curly pondweed bloom?

Give curly pondweed 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 curly pondweed normally bloom?