Fertilising guide
How to fertilise Summer Wave Amethyst Wishbone Flower (Torenia fournieri)— schedule & NPK
Also called Wishbone Flower, Bluewings, Clown Flower.
More about summer wave amethyst wishbone flower
About Summer Wave Amethyst Wishbone Flower
Torenia fournieri · also called Wishbone Flower, Bluewings · flowering
Wishbone Flower is a heat-tolerant annual that thrives in shade with tubular two-toned blooms in amethyst purple and white. A superb choice for hanging baskets and shaded beds, it flowers all summer without deadheading. The ASPCA lists Torenia as non-toxic to dogs and cats, making it a pet-safe choice for the garden.
Growth habit: Spreading, mounding trailing annual
What fertiliser summer wave amethyst wishbone flower actually wants — and why
Summer Wave Amethyst Wishbone Flower is an easy, light foliage feeder — a half-strength balanced liquid feed through the growing months keeps it green without forcing weak, sappy growth.
A balanced general houseplant feed (roughly even N-P-K) is exactly right — it is grown for foliage, so steady, moderate nitrogen for healthy leaves is the goal, not a bloom or root formula.
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 summer wave amethyst wishbone flower: 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 summer wave amethyst wishbone flower, 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 summer wave amethyst wishbone flower:
Feed every two weeks through summer with a balanced liquid fertiliser (e.g., 20-20-20). Regular feeding sustains the continuous-blooming habit; reduce to monthly if growth appears overly lush. Treat that as monthly between spring through early autumn (roughly March to September); ease off in autumn and stop entirely in the low light of winter.
The dormant-season rule matters more than the exact interval: skip feeding entirely when summer wave amethyst wishbone flower 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 summer wave amethyst wishbone flower
Half strength is the safe default for summer wave amethyst wishbone flower — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
Feeding always goes onto already-damp soil, never dry roots — water summer wave amethyst wishbone flower first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the summer wave amethyst wishbone flower watering schedule.
Signs you are over-feeding summer wave amethyst wishbone flower
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for summer wave amethyst wishbone flower:
- Brown, crispy leaf tips and edges with no sign of underwatering.
- A white, crusty salt deposit on the soil surface or pot rim.
- Weak, pale, stretched new growth that flops.
- Lower leaves yellow and drop while the soil is correctly watered.
Signs you are under-feeding summer wave amethyst wishbone flower
- Uniformly pale or yellow-green leaves, oldest first.
- Noticeably small new leaves and stalled growth in good light and season.
- A generally tired, lacklustre look despite correct watering and light.
If the symptoms point at watering, light or roots rather than nutrition, the full summer wave amethyst wishbone flower care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of summer wave amethyst wishbone flower with plain water until it runs freely from the base every couple of months in the feeding season — it washes out the fertiliser salts that cause brown tips.
Organic vs synthetic feeds for summer wave amethyst wishbone flower
Organic options
A diluted seaweed or worm-casting feed, or fish emulsion if you can tolerate the smell indoors. UK: Westland or Baby Bio Organic, dilute seaweed; US: Espoma Indoor! or Neptune's Harvest fish & seaweed. Slow, gentle and hard to overdo.
Synthetic / liquid feeds
A general-purpose houseplant liquid at half strength — UK: Baby Bio, Westland Houseplant Feed or Phostrogen; US: Miracle-Gro Indoor Plant Food or Schultz. Convenient and fast-acting; the only risk is overdoing it.
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 summer wave amethyst wishbone flower — frequently asked questions
What fertiliser does summer wave amethyst wishbone flower need?
A balanced general houseplant feed (roughly even N-P-K) is exactly right — it is grown for foliage, so steady, moderate nitrogen for healthy leaves is the goal, not a bloom or root formula. Summer Wave Amethyst Wishbone Flower is an easy, light foliage feeder — a half-strength balanced liquid feed through the growing months keeps it green without forcing weak, sappy growth.
How often should I feed summer wave amethyst wishbone flower?
Feed every two weeks through summer with a balanced liquid fertiliser (e.g., 20-20-20). Regular feeding sustains the continuous-blooming habit; reduce to monthly if growth appears overly lush. Feed every two weeks through summer with a balanced liquid fertiliser (e.g., 20-20-20). Regular feeding sustains the continuous-blooming habit; reduce to monthly if growth appears overly lush. Treat that as monthly between spring through early autumn (roughly March to September); ease off in autumn and stop entirely in the low light of winter.
What strength of feed for summer wave amethyst wishbone flower?
Half strength is the safe default for summer wave amethyst wishbone flower — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding summer wave amethyst wishbone flower look like?
Brown, crispy leaf tips and edges with no sign of underwatering. A white, crusty salt deposit on the soil surface or pot rim. Weak, pale, stretched new growth that flops. Lower leaves yellow and drop while the soil is correctly watered. Feeding summer wave amethyst wishbone flower year-round on a fixed schedule, including dark winter months, is the most common mistake — it cannot use the nutrients in low light and the surplus simply burns the roots and crusts the soil.
Should I flush the soil of summer wave amethyst wishbone flower?
Flush the pot of summer wave amethyst wishbone flower with plain water until it runs freely from the base every couple of months in the feeding season — it washes out the fertiliser salts that cause brown tips.
Keep reading
- Summer Wave Amethyst Wishbone Flower care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water summer wave amethyst wishbone flower — the watering schedule
- The houseplant fertiliser schedule — feeding through the year
- NPK ratio explained — what the three numbers on the bottle mean
- How to fertilise skyracer moor grass
- How to fertilise blue oat grass
- How to fertilise meadow oat grass
- All 11687 fertilising guides in the Growli library