Why Are My Lemons Small or Dry?

If your lemon tree produces fruit that stays small, thin-skinned, or dries out before ripening, the problem usually comes back to fertiliser imbalances. While water stress and pruning can contribute, nutrient deficiencies are the main reason lemons fail to size up or hold juice. Correcting the fertiliser program is the fastest way to restore plump, juicy fruit.

The most common culprit is a lack of potassium, the nutrient responsible for fruit filling, sweetness, and juice quality. Without enough potassium, lemons may form but remain undersized and fibrous. Inconsistent feeding also plays a role: many backyard lemon trees are fed once a year, which isn’t enough to support continuous fruiting. Over-fertilising with nitrogen creates lots of foliage but starves fruit of the potassium it needs to develop properly.

By balancing fertiliser inputs and feeding through the growing season, you can quickly improve fruit size and restore juiciness in the next harvest cycle.

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Fertiliser Mistakes That Cause Small or Dry Lemons

Low Potassium Levels: The most common reason for undersized, dry fruit. Potassium drives fruit enlargement and juice development.
Excess Nitrogen: Encourages leafy growth but diverts energy away from fruit development.
Infrequent Feeding: Once-a-year fertilising leaves the tree depleted during critical fruiting months.
Timing Errors: Missing mid-summer and autumn feeds weakens the tree during fruit filling, leading to poor fruit quality.
Soil Leaching: In sandy Australian soils or potted lemons, nutrients wash out quickly, starving the tree if not replenished.

The solution is to use a complete fertiliser with strong potassium content alongside nitrogen and phosphorus. Complete Grow NPK 20-20-20 supplies the balanced nutrition lemons need for both healthy foliage and large, juicy fruit. Apply every 4–6 weeks during active growth, especially through summer when fruit are swelling on the tree.

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FAQs About Small or Dry Lemons

Why are my lemons so small?
Usually due to low potassium or irregular fertilising. The tree can’t supply enough energy to fill fruit properly.

Why are my lemons dry inside?
Nutrient deficiencies and heat stress can both reduce juice. Consistent fertilising and watering prevent dry fruit.

Can over-fertilising cause small lemons?
Yes. Too much nitrogen forces leafy growth, leaving fruit underdeveloped.

What fertiliser makes lemons bigger?
A balanced NPK fertiliser with potassium — such as Complete Grow 20-20-20 — supports larger, juicier fruit.

How often should I fertilise to avoid small fruit?
Every 4–6 weeks in spring, summer, and autumn. Regular light feeds are better than one heavy annual application.