Growli
Let's go

Fertilising guide

How to fertilise Dahlia 'Bora Bora' (Dahlia 'Bora Bora')— schedule & NPK

Also called Bora Bora dahlia, lavender lilac dahlia, decorative dahlia.

More about dahlia 'bora bora'

About Dahlia 'Bora Bora'

Dahlia 'Bora Bora' · also called Bora Bora dahlia, lavender lilac dahlia · flowering

Dahlia 'Bora Bora' is a decorative dahlia bearing large lavender-lilac blooms feathered with white and cream from midsummer to first frost. Grown from a frost-tender tuber, it thrives in full sun and rich, well-drained soil, and rewards deadheading with months of cut-flower colour. In cold climates, lift and store the tubers over winter.

Growth habit: Upright, bushy, branching herbaceous perennial growing from a tuberous root, producing tall flowering stems that benefit from staking.

Watch for — Few flowers, leggy growth: Too much shade or excess nitrogen drives soft foliage and weak stems. Site in full sun, switch to a high-potassium feed, and pinch out the growing tip early to encourage branching.

What fertiliser dahlia 'bora bora' actually wants — and why

Dahlia 'Bora Bora' is a heavy-blooming flower with a big appetite — a regular high-potash feed through the season is what drives a long, dense display.

A high-potassium ("high-potash") flowering feed — tomato-style or a dedicated bloom/rose feed. Potassium powers flowering; a high-nitrogen feed gives you a leafy plant with disappointing bloom.

For the language behind the three numbers on the bottle — what nitrogen, phosphorus and potassium each do — see the NPK ratio explained entry. The short version for dahlia 'bora bora': match the feed to the job the plant is doing right now, not to a generic “plant food” on the shelf.

How often to feed dahlia 'bora bora', and which months

Feeding only earns its keep while the plant is in active growth and can use the nutrients — pour feed into a dormant or low-light plant and it simply builds up as root-burning salt. For dahlia 'bora bora':

Feed every 3-4 weeks during the growing season with a low-nitrogen, high-potassium fertiliser (such as a tomato feed) to favour flowers over leafy growth. Avoid high-nitrogen feeds, which produce lush foliage at the expense of blooms and softer, rot-prone tubers. For a hungry bloomer that means feeding regularly — every 3-4 weeks — right through flowering across the main season (spring through early autumn), tapering as blooming ends.

The dormant-season rule matters more than the exact interval: skip feeding entirely when dahlia 'bora bora' is resting. For the wider context on indoor feeding rhythms across the seasons, the houseplant fertiliser schedule walks through the year month by month.

What strength to mix for dahlia 'bora bora'

Follow the flowering-feed label rate for dahlia 'bora bora', or half strength if feeding very frequently. These plants genuinely use the nutrients — under-feeding shows up fast as a thin display.

Feeding always goes onto already-damp soil, never dry roots — water dahlia 'bora bora' first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the dahlia 'bora bora' watering schedule.

Signs you are over-feeding dahlia 'bora bora'

Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for dahlia 'bora bora':

Signs you are under-feeding dahlia 'bora bora'

If the symptoms point at watering, light or roots rather than nutrition, the full dahlia 'bora bora' care brief covers soil, humidity and the common problems for this species.

Flushing and leaching the salts

Container-grown dahlia 'bora bora' accumulates feed salts fast with frequent feeding — water until it drains each time and flush pots with plain water every few weeks to prevent scorch.

Organic vs synthetic feeds for dahlia 'bora bora'

Organic options

A liquid comfrey or seaweed feed (naturally potassium-rich) plus compost or well-rotted manure as a mulch. UK: comfrey feed, organic Tomorite, or rose feed; US: Espoma Rose-tone or Neptune's Harvest. Feeds and improves soil.

Synthetic / liquid feeds

A high-potash flowering feed on a regular cadence — UK: Tomorite (Levington), Phostrogen or a specialist rose feed; US: Miracle-Gro Bloom Booster or a rose food. Fast, reliable bloom response.

Brand names are examples, not endorsements, and UK and US ranges differ — check the label’s own NPK and dilution rate, since formulations change.

Fertilising dahlia 'bora bora' — frequently asked questions

What fertiliser does dahlia 'bora bora' need?

A high-potassium ("high-potash") flowering feed — tomato-style or a dedicated bloom/rose feed. Potassium powers flowering; a high-nitrogen feed gives you a leafy plant with disappointing bloom. Dahlia 'Bora Bora' is a heavy-blooming flower with a big appetite — a regular high-potash feed through the season is what drives a long, dense display.

How often should I feed dahlia 'bora bora'?

Feed every 3-4 weeks during the growing season with a low-nitrogen, high-potassium fertiliser (such as a tomato feed) to favour flowers over leafy growth. Avoid high-nitrogen feeds, which produce lush foliage at the expense of blooms and softer, rot-prone tubers. Feed every 3-4 weeks during the growing season with a low-nitrogen, high-potassium fertiliser (such as a tomato feed) to favour flowers over leafy growth. Avoid high-nitrogen feeds, which produce lush foliage at the expense of blooms and softer, rot-prone tubers. For a hungry bloomer that means feeding regularly — every 3-4 weeks — right through flowering across the main season (spring through early autumn), tapering as blooming ends.

What strength of feed for dahlia 'bora bora'?

Follow the flowering-feed label rate for dahlia 'bora bora', or half strength if feeding very frequently. These plants genuinely use the nutrients — under-feeding shows up fast as a thin display.

What does over-feeding dahlia 'bora bora' look like?

Lots of lush leaves but few flowers (too much nitrogen). Scorched leaf edges and salt crust from too-strong or too-frequent feeds. Soft, sappy growth prone to aphids and mildew. Using a high-nitrogen general feed on dahlia 'bora bora' is the headline mistake — you grow a big leafy plant with few flowers. The second is simply under-feeding a genuinely hungry bloomer and getting a sparse, short display.

Should I flush the soil of dahlia 'bora bora'?

Container-grown dahlia 'bora bora' accumulates feed salts fast with frequent feeding — water until it drains each time and flush pots with plain water every few weeks to prevent scorch.

Keep reading