Germination temperature
Soil at least 16°C (60°F); best 21-35°C (70-95°F). Wait for soil around 21°C (70°F) before sowing outdoors.
Vegetable growing guide
Zucchini and chappan kaddu are fast, warm-season bush squashes that are best sown directly where they will grow. Warm soil, steady water and good pollination decide most of the harvest.
Soil at least 16°C (60°F); best 21-35°C (70-95°F). Wait for soil around 21°C (70°F) before sowing outdoors.
1.3-2.5 cm (0.5-1 in); seed laid on its edge.
About 5-10 days in warm soil.
Full sun, ideally 8 hours a day.
None needed.
Direct sow preferred; short indoor start of about 3 weeks is possible.
Use plump, unbroken seed. Squash seed is large and germinates quickly in warm soil, so no special treatment is required.
Not needed. The seed coat of Cucurbita pepo is thin enough to take up water on its own.
Not needed. Zucchini is a frost-tender warm-season crop with no cold requirement for germination.
Not needed. Soaking does not compensate for cold soil, and soaked seed rots easily in cool, wet ground. Sow dry seed into moist, warm soil instead.
Squash seed needs soil of at least 16°C (60°F) and germinates best between 21 and 35°C (70-95°F). Seedlings are prone to damping off and seed decay in cool, wet soil, so do not hurry sowing. In most of India this means sowing in late winter to spring, or at the start of the rains in cooler hill areas.
Sow 2.5 cm (1 in) deep outdoors and about 1.3 cm (0.5 in) deep in pots. Lay each flat seed on its edge (on its side) rather than flat; this sheds water and reduces the risk of rotting.
Fertile, well-drained soil enriched with compost. On heavy clay, sow on low hills 5-8 cm (2-3 in) high so the seed does not sit in water.
Keep the soil evenly moist but never waterlogged until seedlings emerge. One deep watering after sowing is usually better than frequent light sprinkling.
Seeds do not need light to germinate, but seedlings need full sun immediately after emergence to stay compact.
Seedlings usually appear in 5-10 days in warm soil; in cool soil emergence is slow and patchy.
Sow 2-3 seeds per station and thin to the single strongest plant. Allow about 90 cm (3 ft) between bush plants, or 60-90 cm (2-3 ft) in rows 90-100 cm (3-3.3 ft) apart. Each plant needs about one square metre.
If you start indoors, sow one seed per 7.5 cm (3 in) pot about 3 weeks before planting out. Plant out young, well-rooted seedlings without disturbing the root ball; older pot-bound plants check badly.
Male flowers usually appear 1-2 weeks before the first female flowers, which have a small fruit behind the petals. Do not worry when early flowers drop; this is normal. First harvest is typically about 50-75 days from sowing, depending on variety and temperature.
Cause: poor pollination, usually in rainy, cool or very hot weather when bees are inactive. Fix: hand-pollinate in the morning. Pick a male flower (long thin stalk, no fruit), remove its petals and brush the pollen onto the centre of an open female flower, or use a small paintbrush.
Cause: only male flowers have opened yet, or excess nitrogen is pushing leaves. Fix: wait 1-2 weeks for female flowers, avoid heavy nitrogen feeding, and do not spray insecticides while flowers are open.
Cause: powdery mildew, very common in warm, dry weather and in dense plantings. Fix: water at the base, not over the leaves; remove the worst affected leaves; space plants for airflow and choose resistant varieties where available.
Cause: damping off in cold, wet soil. Fix: sow only into warm soil, avoid overwatering, and use free-draining hills or raised beds in heavy soil.
Cause: fruits left too long; a missed fruit also slows new flowering. Fix: check plants daily in warm weather and pick regularly.
Pick zucchini at roughly 10-20 cm (4-8 in) long and 3-5 cm (1.25-2 in) thick. Round chappan kaddu and pattypan types are best at 8-10 cm (3-4 in) across. Cut with a knife leaving a short stalk; gloves help, as the stems are prickly.
In the North Indian plains summer squash is grown in the open in spring and summer; in winter it is grown in polyhouses or under plastic low tunnels. In very hot, humid weather expect more pollination problems and powdery mildew.
Plants crop most heavily for a few weeks. Sowing two or three batches through the season keeps a steady supply.
Give about 2.5 cm (1 in) of water a week, more in heat, applied at the base. Mulch to keep fruits clean and soil moist.
If you protect young plants with net or fleece against beetles, remove it when flowering starts so bees can reach the flowers.
Choose dark green zucchini or Indian chappan kaddu seeds from Deodar Seeds for a quick, productive warm-season crop.
The first flowers are usually all male, and female flowers follow 1-2 weeks later. If female flowers open but fruits shrivel, pollination failed; hand-pollinate in the morning with pollen from a male flower.
No. Zucchini seed germinates in 5-10 days in warm soil without soaking. Soaked seed sown into cool soil is more likely to rot.
Set the flat seed on its edge, about 2.5 cm (1 in) deep outdoors. The seedling will orient itself, and edge-on seed is less likely to rot in wet soil.
Yes, both are summer squash forms of Cucurbita pepo. Chappan kaddu usually has round or flattened fruits, while zucchini is long, but sowing and care are the same.