Growli
Let's go

Fertilising guide

How to fertilise Hyacinthus orientalis 'City of Haarlem' (Hyacinthus orientalis 'City of Haarlem')— schedule & NPK

Also called City of Haarlem hyacinth, yellow hyacinth, pale primrose hyacinth.

More about hyacinthus orientalis 'city of haarlem'

About Hyacinthus orientalis 'City of Haarlem'

Hyacinthus orientalis 'City of Haarlem' · also called City of Haarlem hyacinth, yellow hyacinth · flowering

Hyacinthus orientalis 'City of Haarlem' is a soft primrose-yellow Dutch hyacinth, one of the few true yellows, with a fragrant, upright spike in mid to late spring. Growing 20-30 cm, it lights up borders, pots and indoor displays. Plant bulbs in autumn for scented spring colour. The bulbs are toxic to cats and dogs.

Growth habit: Single-spiked, clump-forming bulb with a stout stem of densely packed primrose florets above fleshy, strap-shaped leaves; spikes loosen and shorten in later years. Often slightly later-flowering than other cultivars.

Watch for — Reduced flowering after forcing: Spikes diminish after the first forced year. Plant out, feed, and let the foliage die back to restore the bulb.

What fertiliser hyacinthus orientalis 'city of haarlem' actually wants — and why

Hyacinthus orientalis 'City of Haarlem' feeds for next year, not this one — the critical window is after flowering, while the leaves are still green and recharging the bulb.

A low-nitrogen, potassium- and phosphorus-leaning bulb fertiliser (something like 5-10-10) or bonemeal at planting. High nitrogen grows floppy leaves and rots stored bulbs.

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 hyacinthus orientalis 'city of haarlem': 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 hyacinthus orientalis 'city of haarlem', 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 hyacinthus orientalis 'city of haarlem':

Apply a balanced or high-potassium bulb feed at planting and as spikes emerge. After flowering, liquid feed every 2 weeks until foliage dies back to rebuild the bulb. Keep nitrogen moderate to avoid soft, rot-prone growth. The rhythm: a bulb feed at planting, a light feed as leaves emerge, and — most important — a potassium feed straight after flowering while the foliage is still green and feeding the bulb. Never cut the leaves off early.

The dormant-season rule matters more than the exact interval: skip feeding entirely when hyacinthus orientalis 'city of haarlem' 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 hyacinthus orientalis 'city of haarlem'

Use the bulb-feed label rate for hyacinthus orientalis 'city of haarlem'; the timing (post-bloom, leaves still green) does far more for next year's display than the concentration.

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

Signs you are over-feeding hyacinthus orientalis 'city of haarlem'

Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for hyacinthus orientalis 'city of haarlem':

Signs you are under-feeding hyacinthus orientalis 'city of haarlem'

If the symptoms point at watering, light or roots rather than nutrition, the full hyacinthus orientalis 'city of haarlem' care brief covers soil, humidity and the common problems for this species.

Flushing and leaching the salts

Bulbs are not container-flushed like houseplants; the equivalent is not over-feeding and lifting/dividing congested clumps of hyacinthus orientalis 'city of haarlem' every few years so they are not competing for nutrients.

Organic vs synthetic feeds for hyacinthus orientalis 'city of haarlem'

Organic options

Bonemeal worked in at planting plus a mulch of garden compost or well-rotted leaf-mould is the traditional, reliable approach for hyacinthus orientalis 'city of haarlem'. UK: blood, fish & bone or Westland Bulb Food; US: Espoma Bulb-tone or bonemeal.

Synthetic / liquid feeds

A proprietary bulb fertiliser at planting and a high-potash liquid (tomato feed) after flowering — UK: Westland Bulb Food then Tomorite; US: Miracle-Gro Shake 'n Feed Bulb or a bloom booster post-flower.

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 hyacinthus orientalis 'city of haarlem' — frequently asked questions

What fertiliser does hyacinthus orientalis 'city of haarlem' need?

A low-nitrogen, potassium- and phosphorus-leaning bulb fertiliser (something like 5-10-10) or bonemeal at planting. High nitrogen grows floppy leaves and rots stored bulbs. Hyacinthus orientalis 'City of Haarlem' feeds for next year, not this one — the critical window is after flowering, while the leaves are still green and recharging the bulb.

How often should I feed hyacinthus orientalis 'city of haarlem'?

Apply a balanced or high-potassium bulb feed at planting and as spikes emerge. After flowering, liquid feed every 2 weeks until foliage dies back to rebuild the bulb. Keep nitrogen moderate to avoid soft, rot-prone growth. Apply a balanced or high-potassium bulb feed at planting and as spikes emerge. After flowering, liquid feed every 2 weeks until foliage dies back to rebuild the bulb. Keep nitrogen moderate to avoid soft, rot-prone growth. The rhythm: a bulb feed at planting, a light feed as leaves emerge, and — most important — a potassium feed straight after flowering while the foliage is still green and feeding the bulb. Never cut the leaves off early.

What strength of feed for hyacinthus orientalis 'city of haarlem'?

Use the bulb-feed label rate for hyacinthus orientalis 'city of haarlem'; the timing (post-bloom, leaves still green) does far more for next year's display than the concentration.

What does over-feeding hyacinthus orientalis 'city of haarlem' look like?

Tall, floppy, soft leaves that flop over (too much nitrogen). Soft or rotting bulbs lifted at the end of the season. Lush foliage but few or poor flowers. Cutting or tying off the leaves of hyacinthus orientalis 'city of haarlem' as soon as the flowers fade is the great bulb mistake — the bulb recharges through those leaves for weeks afterward, and removing them early means a weak or blind display next year.

Should I flush the soil of hyacinthus orientalis 'city of haarlem'?

Bulbs are not container-flushed like houseplants; the equivalent is not over-feeding and lifting/dividing congested clumps of hyacinthus orientalis 'city of haarlem' every few years so they are not competing for nutrients.

Keep reading