Germination temperature
Warm; 81-86% germination at 25 °C (77 °F) in laboratory tests.
Tree growing guide
Bael (wood apple, bilva) is a thorny, deciduous fruit tree native to the Indian subcontinent, valued for its hard-shelled aromatic fruit and its tolerance of poor, dry soils. Seed taken fresh from ripe fruit germinates well within a few weeks, and the seedlings make good rootstocks for budding a named variety.
Warm; 81-86% germination at 25 °C (77 °F) in laboratory tests.
Shallow, about the thickness of the flat seed, in bags or a nursery bed.
Usually 2-3 weeks under favourable conditions.
Not critical for germination; seedlings grow best in sun with light shade at first.
Wash off the sticky mucilage; sow fresh seed without other treatment.
Raise in polythene bags; plant out or bud seedlings at 8-12 months or older.
Each ripe fruit holds about 10-15 flat, oblong seeds roughly 1 cm (0.4 in) long, each covered with woolly hairs and sitting in a sac of mucilage that hardens as it dries. Break open a fully ripe fruit, scoop out the seeds and wash the sticky mucilage off in water. A thousand seeds weigh about 94 g.
Not needed. Untreated seed germinated at over 80% in laboratory tests.
Not needed, and cold is harmful: in one study seed held at 0 °C (32 °F) for a week did not germinate at all.
Not required: fresh, moist seed can be sown straight after washing. Seed that has dried after cleaning can be soaked overnight in water to rehydrate it before sowing.
Germinate in warm weather. Laboratory germination at 25 °C (77 °F) was 81-86%. In most of India, sow soon after the fruit ripens in the warm months.
Sow the flat seeds shallowly, about the seed's own thickness deep, one or two per bag.
Perforated polythene bags (for example 25 x 15 cm) or a bed filled with nursery soil mixed with well-rotted manure, kept free-draining.
Keep the medium evenly moist until the seedlings emerge; do not let freshly sown seed dry out.
Light is not needed for germination. Bags can stand in the open or under light shade.
Viable seeds usually sprout within 2-3 weeks in warm conditions. Keep the medium moist for at least four weeks before deciding a sowing has failed.
Keep seedlings in their bags through the first season. Seedlings about 8-12 months old, or older, are used as rootstocks or planted out.
Seedling trees start bearing at 6-7 years and vary in fruit quality, while budded trees bear from about 5 years. In West Bengal trials, nursery budding or grafting in March gave 70-90% and 85-95% success; in Gujarat, patch budding of 8-12-month-old rootstocks in the field in May-June, before the monsoon, gave good establishment under rainfed conditions.
Plant out at the onset of the monsoon so roots establish while the soil is moist, and water through the first dry season.
Cause: bael seed loses viability within months when stored warm, and dies if overdried or chilled to 0 °C. Fix: sow fresh seed; if you must store it, keep it cool (about 10 °C / 50 °F) and do not dry it out completely.
Cause: mucilage left on the seed and a waterlogged medium. Fix: wash seed clean and use free-draining nursery soil.
Cause: seedlings vary and may carry small or very seedy fruit. Fix: bud or graft seedlings with a good variety.
Bael does best on rich, well-drained soil but also grows on stony, alkaline and swampy soils with a pH of 5-8, which makes it useful on difficult land.
The tree needs a long dry season to fruit well. In India it flowers in April-May, and the fruit takes 10-11 months to ripen.
Bael has sharp thorns; plant it away from paths and wear gloves when budding or pruning.
Seed can be sown directly for a hedge in two rows about 15 x 30 cm (6 x 12 in) apart. The tree coppices vigorously and sends up root suckers if roots are damaged.
Grow bael from seed as a hardy fruit tree or as rootstock for budding a named variety.
Not long under warm conditions; one study described a normal viability of 6-9 months. Sources disagree on how well the seed tolerates drying, so sowing fresh seed is the safest choice.
Seedling trees begin bearing at about 6-7 years; budded trees on seedling rootstocks bear from about 5 years.
Not if they are fresh. Wash off the sticky mucilage and sow; an overnight soak only helps seed that has dried out.