Germination temperature
Warm; nurseries pre-soak seed in water at 29 °C (85 °F).
Visit deodar-seeds.in Fruit growing guide
Orange seed sprouts readily if it is sown fresh and never dried out, and one seed often gives several seedlings. Seedling trees can take 10-15 years to fruit, so many growers use them as rootstocks.
Warm; nurseries pre-soak seed in water at 29 °C (85 °F).
0.5-1 cm (1/4-1/2 in).
A few days with the seed coat removed; slower and less even with it on.
Bright light for seedlings; full sun for trees.
Do not let seed dry out; a 24-hour soak helps.
Sow one seed per cell, then pot on.
Rinse the seeds free of pulp and sow them soon. Citrus seed loses viability when it dries too far: UF/IFAS reports that grapefruit seed will not germinate below 6% moisture. If you must store seed, keep it with its coat in a sealed bag in the fridge at 4-8 °C (39-46 °F).
Not needed, but peeling off the tough outer seed coat speeds germination to a few days and makes it more even. Nurseries remove it chemically; at home you can nick and peel it carefully with a fingernail after soaking.
Not needed. Orange seed needs warmth, not cold.
Soak seed that has dried a little in water at about 29 °C (85 °F) for 24 hours before sowing. UF/IFAS uses this to make germination faster and more uniform.
Keep the tray warm, out of draughts and cold floors; nurseries pre-soak seed at 29 °C (85 °F) to speed germination. Cold, wet compost slows germination and invites rot.
Sow one seed per cell, 0.5-1 cm (1/4-1/2 in) deep.
A sterile, free-draining mix such as peat or coir with perlite. Sterile mix matters because Phytophthora damping-off is the main seedling disease.
Keep the mix moist but never waterlogged.
Light is not needed for germination; give bright light as soon as shoots appear.
Peeled seed comes up uniformly within a few days. Seed with its coat on is slower and less even, so give it several weeks before giving up.
Most orange seeds are polyembryonic: one seed can send up two or more shoots. Most are nucellar seedlings, genetically identical to the mother tree. Any seedling that looks different or grows weakly is usually the sexual (zygotic) seedling; remove it, or grow it on separately.
Move strong, healthy seedlings into deeper pots once they are tall enough to handle, and discard stunted ones. Raised benches or shelves keep soil splash, and the diseases it carries, off young plants.
Plant at the start of the rains; TNAU plants from July to September in 75 cm (30 in) pits filled with topsoil and about 10 kg of manure, 7 m (23 ft) apart, with a stake. Water well, then about every 10 days, and avoid waterlogging.
Cause: seed dried out or was stored warm. Fix: sow fresh seed, or soak it for 24 hours and peel the outer coat before sowing.
Cause: Phytophthora damping-off. Fix: use sterile mix and clean pots, avoid overwatering and keep trays off the ground.
Cause: citrus leaf miner on new flush. Fix: TNAU recommends neem oil (3%) or neem seed kernel extract (5%) on the new growth.
Cause: zinc deficiency (little leaf). Fix: spray zinc sulphate at new flush; TNAU uses 1% at flush, a month later, at flowering and at fruit set.
Cause: the citrus root nematode. Fix: TNAU applies Pseudomonas fluorescens around the root zone and avoids planting into infested nursery soil.
A seed-grown citrus tree can take 10-15 years to fruit, while budded sweet orange starts bearing in the fifth year in TNAU's guide. For a named variety such as Sathukudi (mosambi), bud it onto a vigorous seedling rootstock; Rangpur lime and rough lemon are the usual choices in India.
Sweet orange yields best in a fairly dry climate with distinct summer and winter seasons; TNAU recommends tropical zones below 500 m with 50-75 cm of rain from June to September.
Deep, well-drained loam with pH 6.5-7.5. Avoid salty irrigation water and waterlogging, especially during the monsoon.
Increase manure and NPK each year as the tree grows, and give micronutrient sprays (zinc, manganese, iron, boron) at each new flush.
Sow orange seed fresh and warm for vigorous seedlings and rootstocks.
Orange seeds are usually polyembryonic. Most of the extra seedlings are nucellar clones of the mother tree; one may be a sexual seedling that differs from it.
Yes, but slowly: a seed-grown citrus tree can take 10-15 years to fruit, against about five years for a budded tree. Many growers use seedlings as rootstocks and bud a named variety onto them.
No. Drying harms citrus seed. Sow it fresh, or soak seed that has dried a little for 24 hours in warm water first.