How to use

Choose your crop. The days to first harvest and how long the harvest lasts fill in automatically.
Choose whether you are sowing seed or transplanting a seedling.
Pick the date. It starts at today.
If transplanting, enter the seedling's age in days since sowing.
If your seed packet gives different days, type them in — the packet knows its own variety best.
Read the first-harvest dates, the harvest window and the date to sow the next batch.

How it's calculated

First harvest = start date + earliest days … start date + latest days.
When transplanting, the seedling has already used part of that time in the tray: days after transplanting = days from sowing − seedling age.
Harvest window = earliest harvest date + how long the harvest lasts.
Next sowing = sowing date + how long the harvest lasts, so the next batch is ready about when this one finishes.

Dates are counted as whole calendar days in your own time zone. The ranges are typical for lowland Malaysia and match our growing guides:

Crop	Days from sowing	Harvest lasts about
Kangkung	21–30	6 weeks (cut and regrow)
Bayam	21–35	4 weeks (pinching)
Choy sum	30–40	2 weeks
Pak choy	30–45	2 weeks
Lettuce	35–55	3 weeks
Coriander	30–45	3 weeks
Thai basil	45–60	4 months
Okra, long bean	45–60	4–6 weeks
Cucumber	40–55	4 weeks
Tomato	80–100	2 months
Cili padi	90–120	6 months or more
Brinjal	90–110	4 months

Bitter gourd, loofah, pumpkin, radish, sweet corn, spring onion, watermelon, kailan, marigold and sunflower are in the list too; for flowers the date is the first bloom.

Worked example

Choy sum sown on 1 March 2027 (30–40 days, harvest lasts about 14 days):

First harvest: 1 Mar + 30 days = 31 Mar 2027, to 1 Mar + 40 days = 10 Apr 2027
Harvest window: 31 Mar to 14 Apr 2027
Sow the next batch around 1 Mar + 14 days = 15 Mar 2027

The calculator opens with choy sum and today's date, so you will see the same 30–40 days counted from today.

Transplanting a 30-day-old brinjal seedling on 1 March 2027: 90 − 30 = 60 and 110 − 30 = 80 days, so first fruit from about 30 Apr to 20 May 2027.

Tips

Write the sowing date on a plant label. It makes every later date easy to work out.
Many hybrid chili and tomato packets count days from transplanting, not sowing. Check before you type them in.
Shade, very heavy rain and poor feeding push harvest later; hot sunny weeks usually bring it forward a little.
For leafy greens, sow small batches every 2–3 weeks rather than one big sowing.

CalculatorsSeedling Tray CalculatorHow many seeds to sow in 32, 50, 72, 105, 128 or 200-cell seedling trays, how many seedlings to expect — or how many trays you need for the seedlings you want.

GuidesHow to Grow Kangkung (Water Spinach) at Home in MalaysiaGrow kangkung from seed in pots, polybags or water. Sowing, watering, feeding, pests and cut-and-come-again harvesting for Malaysian homes.

GuidesHow to Grow Cili Padi (Bird's Eye Chili) at Home in MalaysiaGrow cili padi in pots or polybags in Malaysia — sowing, staking, feeding for fruit, and organic fixes for thrips, mites and leaf curl.

GuidesHow to Grow Cherry Tomatoes in Malaysia's Lowland HeatGrow cherry tomatoes in pots in lowland Malaysia — heat-tolerant types, rain shelter, staking, feeding, and fixes for blossom-end rot and wilt.

FAQ

Why is it a range and not one date? Variety, sun, weather and feeding all change growth speed. Start checking at the earliest date.

What does "harvest lasts" mean? How long one sowing usually keeps giving a useful harvest — a couple of weeks for choy sum, months for chili. It is approximate; change it to match your own plants.

My seedling is bought. How old is it? Ask the seller, or estimate: most vegetable seedlings with 3–4 true leaves are about 2–4 weeks old; chili and brinjal often 4–6 weeks.

Can I use this for crops not in the list? Choose "Other crop" and enter the days from the seed packet.