Getting it to bloom

Why won't my Common Cordgrass bloom? (and how to make it flower)

Also called Common cordgrass, English cordgrass, Rice grass (Spartina anglica).

More about common cordgrass

About Common Cordgrass

Spartina anglica · also called Common cordgrass, English cordgrass · flowering

Spartina anglica is an allotetraploid hybrid perennial grass that originated in southern England in the 19th century and is now a dominant pioneer of intertidal mudflats and saltmarshes worldwide. It thrives in waterlogged, saline, anaerobic mud in the intertidal zone and is exceptional among flowering plants in tolerating daily tidal submersion. The most critical care fact is that it requires intertidal, brackish or saline substrate and standing, saline water for establishment — it is a specialist mud-flat coloniser, not a garden plant. Common cordgrass is not listed as toxic by the ASPCA and is considered non-toxic to pets.

Plant type: flowering

The reasons common cordgrass isn't blooming

Almost every non-blooming common cordgrass 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 common cordgrass 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 common cordgrass to flower

Maximise sun. Give common cordgrass 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 common cordgrass and get the feeding right with the common cordgrass 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

Common Cordgrass 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 common cordgrass care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Common Cordgrass blooming — frequently asked questions

Why won't my common cordgrass flower?

Common Cordgrass 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 common cordgrass bloom?

Give common cordgrass 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 common cordgrass normally bloom?