Nursery Sowing & Hit the Field on Time

It starts from when you need transplants in the field and subtracts the crop's optimum transplant age in days: sow date = field-ready date − optimum age. For tomato (optimum 27 days), to transplant on 1 July the nursery must be sown around 4 June. For staggered batches it does this for each batch, offsetting the field date by your chosen stagger interval.

It is the seedling age, in days from sowing, at which a transplant establishes best — old enough to handle and survive transfer, young enough to root quickly without setback. The embedded table gives a minimum, optimum and maximum age plus a target leaf stage for each crop. Rice is about 23 days, tomato 27, onion 48, while young SRI rice is just 12 days.

They become overgrown — root-bound in the tray, stressed, and prone to transplant shock. In many crops overage also triggers premature flowering or bolting (onion, brassicas), which permanently caps yield. The tool reports an overgrown date (sow date + maximum age) for each batch so you can see the deadline by which they must be in the ground.

It is the spread between the earliest usable age and the overgrown threshold — the band of days during which a batch can safely be transplanted. A wide window (say 22 days for chilli) gives flexibility if land or weather delays you; a narrow window (about 7 days for SRI rice) demands tight scheduling. The tool shows the window length per batch.

Instead of one big planting, you sow several nursery batches a few days apart so they become field-ready in sequence, spreading transplanting labour and extending harvest. Set the number of batches and the stagger interval (for example 4 batches, 7 days apart); the tool back-calculates a sow date for each so each batch is ready exactly when you want to plant it.

The tool uses a trays-per-1000-transplants figure for each crop (based on roughly 98-cell trays) and scales it to your total transplant number, then divides across batches. Small-seeded crops in plug trays need more trays per 1000; crops raised as slips or in bags show zero trays. It reports trays per batch and the total so you can order seedling supplies.

Over thirty transplanted crops across cereals (rice, SRI rice), vegetables (tomato, brinjal, chilli, capsicum, cabbage, cauliflower, broccoli, onion, leek, lettuce, cucurbits, okra and more), spices (fennel, coriander) and plantation crops (tobacco, papaya, coffee). The reference table on this page lists each crop's age window, leaf stage and tray requirement.

Cucumber, melon, pumpkin and gourds resent root disturbance, so they are raised for only 12–22 days and transplanted at the 2–3 true-leaf stage while the root ball is small and intact. Hold them longer and the roots circle and tear on transfer, setting the plant back badly. Their narrow window is why precise nursery timing matters most for these crops.

Yes — that is the main use. Enter the date your previous crop clears or the soil is workable as the first field-ready date, and the tool tells you exactly when to sow the nursery so the transplants are ready then, not weeks early (overgrown) or late (idle land). Stagger the batches to match a rolling land-availability schedule.

The ages are measured from sowing, and germination is included within the optimum-age figure — the table reflects days from sowing to a transplant-ready seedling at the listed leaf stage. If you direct-prime or use older seed with slow emergence, add a day or two to the sow date to be safe, since the age clock effectively starts at sowing.

Both. The age windows and leaf stages apply to seedlings however they are raised; the tray count assumes cell trays and is the part that differs for bed-grown or bag-grown stock (shown as zero trays). Use the dates for any nursery system and treat the tray figure as relevant only if you raise plugs.