Step-by-Step Growing Guide
Watermelon is the most heat-demanding common fruit crop — it needs 3+ months of sustained warm weather, minimum 120 frost-free days, and soil that stays above 21°C. Start seeds indoors 3–4 weeks before transplanting — watermelons resent root disturbance, so use biodegradable pots. Transplant when soil is at least 21°C and all frost risk has passed. Grow on raised, mounded hills of rich, sandy-loam soil at pH 6.0–6.8, incorporating compost and 200g per square metre of balanced fertiliser. Space plants 90–120cm apart on hills 1.5–2m apart — each vine needs enormous ground space. Water deeply and consistently — 2.5–4cm per week — but reduce significantly once fruit reaches full size; excess moisture during ripening dilutes sweetness and can split fruit. Mulch with black plastic for soil warmth. Feed with nitrogen fertiliser until the vine starts running, then switch to a phosphorus-potassium feed (5-10-10) at flowering, then potassium only as fruit develops.
