Fertilising guide
How to fertilise Mignonette (Reseda odorata)— schedule & NPK
Also called Mignonette, Garden mignonette, Sweet mignonette.
More about mignonette
About Mignonette
Reseda odorata · also called Mignonette, Garden mignonette · flowering
Mignonette is a cool-season annual beloved since the 18th century for its intensely sweet, honey-like fragrance rather than its modest, small yellowish-green flowers. Native to North Africa, it thrives in cool summers and poor to moderately fertile, well-drained, slightly alkaline soil. Best direct-sown; does not transplant well. Excellent for cutting gardens.
Growth habit: Upright to sprawling, bushy cool-season annual; produces racemes of small, fragrant flowers on branching stems
Watch for — Aphid infestations: Soft stems and foliage attract aphids, particularly in spring. Inspect regularly and use a strong water jet to dislodge, or apply insecticidal soap. Avoid high-nitrogen feeding, which produces the lush growth aphids prefer.
What fertiliser mignonette actually wants — and why
Mignonette 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 mignonette: 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 mignonette, 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 mignonette:
Apply a balanced granular fertiliser at sowing time. Avoid high-nitrogen feeds. One or two liquid feeds with a low-nitrogen, high-potassium formula during the growing season is sufficient to support flowering without sacrificing fragrance. Treat that as sparingly through the growing season 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 mignonette 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 mignonette
Half strength is the safe default for mignonette — 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 mignonette first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the mignonette watering schedule.
Signs you are over-feeding mignonette
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for mignonette:
- 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 mignonette
- 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 mignonette care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of mignonette 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 mignonette
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 mignonette — frequently asked questions
What fertiliser does mignonette 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. Mignonette 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 mignonette?
Apply a balanced granular fertiliser at sowing time. Avoid high-nitrogen feeds. One or two liquid feeds with a low-nitrogen, high-potassium formula during the growing season is sufficient to support flowering without sacrificing fragrance. Apply a balanced granular fertiliser at sowing time. Avoid high-nitrogen feeds. One or two liquid feeds with a low-nitrogen, high-potassium formula during the growing season is sufficient to support flowering without sacrificing fragrance. Treat that as sparingly through the growing season 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 mignonette?
Half strength is the safe default for mignonette — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding mignonette 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 mignonette 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 mignonette?
Flush the pot of mignonette 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
- Mignonette care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water mignonette — 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 common milkweed
- How to fertilise spider milkweed
- How to fertilise green milkweed
- All 8452 fertilising guides in the Growli library