Zucchini

Zucchini is the classic beginner mistake: it looks small in the seedling pot and becomes a 4-foot plant in six weeks. It needs the biggest container on this list and full sun, but if you give it those two things it is almost embarrassingly productive. Grow one plant, not three.

How to grow it

• Use a 7-gallon pot minimum — a 5-gallon pot will produce female flowers that abort before fruit sets.
• Sow directly after the soil is above 65°F, or start indoors two weeks before and transplant gently.
• Feed heavily: compost in the mix plus a liquid feed every two weeks. Squash are heavy feeders.
• Hand-pollinate if fruit keeps shrivelling: move pollen from a male flower to a female flower with a brush in the morning.
• Water at the base deeply twice a week rather than lightly every day.

What goes wrong

• Fruit shrivels and drops: poor pollination or too-small a pot. Hand-pollinate first, then check pot size.
• Powdery mildew late in the season: cut back affected leaves and keep watering at the base.
• Squash vine borers: sudden wilting of one vine. Slit the stem lengthwise, remove the larva, and bury the stem.

Harvesting

Harvest at 6–8 inches. Zucchini doubles in two days and a 12-inch squash is woody and seedy.

• Check plants daily once flowering starts — this is not a crop you pick weekly.
• Cut with a knife, leaving an inch of stem on the fruit.
• Blossoms are edible; pick a few male flowers (the ones with no fruit behind them) and stuff them.

Varieties that work in pots

Black Beauty · Eight Ball · Trombocino (climbing) · Dunja (mildew resistant)

Seed is cheap; the pot and the mix are where the money goes. Links to search results on Amazon are affiliate links — see our disclosure.