Fertilising guide
How to fertilise Mandevilla 'Sun Parasol Crimson' (Mandevilla 'Sun Parasol Crimson')— schedule & NPK
Also called Sun Parasol Crimson mandevilla, crimson dipladenia.
More about mandevilla 'sun parasol crimson'
About Mandevilla 'Sun Parasol Crimson'
Mandevilla 'Sun Parasol Crimson' · also called Sun Parasol Crimson mandevilla, crimson dipladenia · tropical
'Sun Parasol Crimson' is a vigorous Mandevilla hybrid grown for masses of velvety, deep crimson-red trumpet flowers against glossy dark green leaves. A heat-loving tropical twining vine, it flowers all summer in sun and warmth, climbing a trellis or trailing from containers. Treat as a frost-tender patio or conservatory plant in cool climates.
Growth habit: Frost-tender evergreen twining climber; this hybrid is bushy and free-flowering, suited to trellises, obelisks and trailing from hanging containers.
Watch for — Few flowers: Too little sun or excess nitrogen produces foliage but few crimson blooms. Give full sun and switch to a high-potassium feed to maximise flowering.
What fertiliser mandevilla 'sun parasol crimson' actually wants — and why
Mandevilla 'Sun Parasol Crimson' 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 mandevilla 'sun parasol crimson': 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 mandevilla 'sun parasol crimson', 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 mandevilla 'sun parasol crimson':
Feed every 1-2 weeks through spring and summer with a high-potassium fertiliser (such as tomato feed) to drive continuous flowering. Stop feeding in autumn and winter. Excess nitrogen produces leaves at the expense of blooms. Treat that as every 1-2 weeks 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 mandevilla 'sun parasol crimson' 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 mandevilla 'sun parasol crimson'
Half strength is the safe default for mandevilla 'sun parasol crimson' — 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 mandevilla 'sun parasol crimson' first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the mandevilla 'sun parasol crimson' watering schedule.
Signs you are over-feeding mandevilla 'sun parasol crimson'
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for mandevilla 'sun parasol crimson':
- 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 mandevilla 'sun parasol crimson'
- 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 mandevilla 'sun parasol crimson' care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of mandevilla 'sun parasol crimson' 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 mandevilla 'sun parasol crimson'
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 mandevilla 'sun parasol crimson' — frequently asked questions
What fertiliser does mandevilla 'sun parasol crimson' 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. Mandevilla 'Sun Parasol Crimson' 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 mandevilla 'sun parasol crimson'?
Feed every 1-2 weeks through spring and summer with a high-potassium fertiliser (such as tomato feed) to drive continuous flowering. Stop feeding in autumn and winter. Excess nitrogen produces leaves at the expense of blooms. Feed every 1-2 weeks through spring and summer with a high-potassium fertiliser (such as tomato feed) to drive continuous flowering. Stop feeding in autumn and winter. Excess nitrogen produces leaves at the expense of blooms. Treat that as every 1-2 weeks 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 mandevilla 'sun parasol crimson'?
Half strength is the safe default for mandevilla 'sun parasol crimson' — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding mandevilla 'sun parasol crimson' 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 mandevilla 'sun parasol crimson' 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 mandevilla 'sun parasol crimson'?
Flush the pot of mandevilla 'sun parasol crimson' 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
- Mandevilla 'Sun Parasol Crimson' care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water mandevilla 'sun parasol crimson' — 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 monstera
- How to fertilise pothos
- How to fertilise fiddle leaf fig
- All 3899 fertilising guides in the Growli library