How do I store tomatoes and soft vegetables for a few extra days without spoilage?

Soft vegetables spoil fast because they keep breathing and losing water after harvest, and heat speeds everything up, so the basics are pick cool, handle gently, and keep cool and shaded. Harvest tomatoes and greens in the cool morning, not in afternoon heat, and move them straight into shade. Handle them gently and use crates instead of loose heaps or overfilled sacks, because most loss is from bruising during dumping and transport, and a bruise quickly turns to rot. Sort out any damaged, overripe or diseased pieces immediately, since one rotting tomato spoils the lot around it. For tomatoes, picking at the mature green to breaker stage rather than fully ripe gives you more days of shelf life for distant markets. Keep produce cool and shaded with airflow; even a cool room, an earthen or evaporative cool chamber, or simply shade and a damp surrounding can extend life by a day or two without a cold store. Leafy vegetables last longer kept slightly moist and shaded but not waterlogged. The biggest gains are usually from gentle handling and getting produce to market with the least delay. For longer holding, a cold chain is the real answer. Verify low cost cooling options for your area with your KVK or horticulture office.