Fertilising guide
How to fertilise Dutch medlar (Mespilus germanica 'Dutch')— schedule & NPK
Also called Dutch medlar, Large Dutch medlar, medlar 'Dutch'.
More about dutch medlar
About Dutch medlar
Mespilus germanica 'Dutch' · also called Dutch medlar, Large Dutch medlar · edible
An ancient, vigorous cultivar producing the largest fruits of the commonly grown medlars — russet-brown pomes up to 5 cm across with distinctive laurel-like foliage. 'Dutch' forms a spreading small tree, fully hardy to H6, and is appreciated for ornamental and culinary value. Fruits require bletting after frost before the sweet, tart flesh is enjoyable.
Growth habit: Deciduous small spreading tree or large shrub; vigorous with a wide, bushy canopy; more spreading in habit than 'Nottingham'; large, distinctive laurel-like leaves; white 5 cm flowers in late spring
What fertiliser dutch medlar actually wants — and why
Dutch medlar feeds in two distinct phases — balanced to build the plant, then high-potassium the moment flowering starts to set and fill a heavy crop.
Balanced (even N-P-K) at planting for roots and frame, then switch to a high-potassium ("high-potash") tomato-style feed once the first flowers open — potassium is what sizes and ripens fruit, not nitrogen.
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 dutch medlar: 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 dutch medlar, 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 dutch medlar:
Annual application of a balanced fertiliser or well-rotted manure mulch in early spring is sufficient. 'Dutch' is vigorous and can over-grow if fed heavily; moderate nutrition produces better-quality rather than excessive fruit. So: a balanced feed or compost at planting, then a high-potash liquid every 1-2 weeks from first flower through harvest across the main season (spring through early autumn).
The dormant-season rule matters more than the exact interval: skip feeding entirely when dutch medlar 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 dutch medlar
Follow the crop-feed label rate for dutch medlar — these are calibrated for hungry vegetables. Consistency through fruiting matters more than strength; erratic feeding causes problems like blossom-end rot.
Feeding always goes onto already-damp soil, never dry roots — water dutch medlar first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the dutch medlar watering schedule.
Signs you are over-feeding dutch medlar
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for dutch medlar:
- Vigorous dark-green leafy growth but few flowers or fruit (excess nitrogen).
- Lush foliage hiding the crop; soft growth prone to pests and disease.
- Salt crust on the soil and scorched leaf edges in containers.
Signs you are under-feeding dutch medlar
- Pale, yellowing lower leaves and stunted growth.
- Small fruit, poor set, and a quickly exhausted plant.
- Blossom-end rot and weak cropping from erratic or insufficient feeding.
If the symptoms point at watering, light or roots rather than nutrition, the full dutch medlar care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
In containers, fertiliser salts build up fast — water dutch medlar thoroughly so excess drains from the base each time, and flush pots with plain water every few weeks to prevent a damaging salt build-up.
Organic vs synthetic feeds for dutch medlar
Organic options
Garden compost or well-rotted manure dug in before planting, plus a liquid comfrey or seaweed feed once fruiting starts. UK: comfrey feed or organic Tomorite; US: Espoma Tomato-tone or Neptune's Harvest. Builds soil and feeds in one.
Synthetic / liquid feeds
A balanced feed at planting then a high-potash tomato feed in fruiting — UK: Growmore at planting then Tomorite (Levington) or Phostrogen; US: a balanced 10-10-10 then Miracle-Gro Tomato or a bloom booster.
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 dutch medlar — frequently asked questions
What fertiliser does dutch medlar need?
Balanced (even N-P-K) at planting for roots and frame, then switch to a high-potassium ("high-potash") tomato-style feed once the first flowers open — potassium is what sizes and ripens fruit, not nitrogen. Dutch medlar feeds in two distinct phases — balanced to build the plant, then high-potassium the moment flowering starts to set and fill a heavy crop.
How often should I feed dutch medlar?
Annual application of a balanced fertiliser or well-rotted manure mulch in early spring is sufficient. 'Dutch' is vigorous and can over-grow if fed heavily; moderate nutrition produces better-quality rather than excessive fruit. Annual application of a balanced fertiliser or well-rotted manure mulch in early spring is sufficient. 'Dutch' is vigorous and can over-grow if fed heavily; moderate nutrition produces better-quality rather than excessive fruit. So: a balanced feed or compost at planting, then a high-potash liquid every 1-2 weeks from first flower through harvest across the main season (spring through early autumn).
What strength of feed for dutch medlar?
Follow the crop-feed label rate for dutch medlar — these are calibrated for hungry vegetables. Consistency through fruiting matters more than strength; erratic feeding causes problems like blossom-end rot.
What does over-feeding dutch medlar look like?
Vigorous dark-green leafy growth but few flowers or fruit (excess nitrogen). Lush foliage hiding the crop; soft growth prone to pests and disease. Salt crust on the soil and scorched leaf edges in containers. Staying on a high-nitrogen feed once dutch medlar starts flowering is the classic error — you get a huge leafy plant and a disappointing crop. Switch to high-potash the moment flowers appear.
Should I flush the soil of dutch medlar?
In containers, fertiliser salts build up fast — water dutch medlar thoroughly so excess drains from the base each time, and flush pots with plain water every few weeks to prevent a damaging salt build-up.
Keep reading
- Dutch medlar care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water dutch medlar — 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 northline saskatoon
- How to fertilise allegheny serviceberry
- How to fertilise snowy mespilus
- All 8452 fertilising guides in the Growli library