Getting it to bloom

Why won't my Dryopteris carthusiana bloom? (and how to make it flower)

Also called Spinulose Wood Fern, Narrow Buckler Fern, Toothed Wood Fern (Dryopteris carthusiana).

More about dryopteris carthusiana

About Dryopteris carthusiana

Dryopteris carthusiana · also called Spinulose Wood Fern, Narrow Buckler Fern · flowering

Dryopteris carthusiana is a graceful, deciduous-to-semi-evergreen wood fern of damp woods, swamps, and shaded banks across Europe and North America. It forms loose clumps of narrow, lacy, tripinnate fronds with spiny-toothed segments, lighter and airier than the broad buckler fern. Adaptable and hardy, it suits moist, shaded gardens, bog margins, and naturalistic woodland plantings in cool climates.

Plant type: flowering

The reasons dryopteris carthusiana isn't blooming

Almost every non-blooming dryopteris carthusiana 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 dryopteris carthusiana 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 dryopteris carthusiana to flower

Maximise sun. Give dryopteris carthusiana 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 dryopteris carthusiana and get the feeding right with the dryopteris carthusiana 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

Dryopteris carthusiana 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 dryopteris carthusiana care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Dryopteris carthusiana blooming — frequently asked questions

Why won't my dryopteris carthusiana flower?

Dryopteris carthusiana 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 dryopteris carthusiana bloom?

Give dryopteris carthusiana 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 dryopteris carthusiana normally bloom?