1. General Introduction
Mai Son custard apple (known locally as Na Mai Son) is a renowned specialty fruit of Mai Son District, Son La Province. Thanks to its fertile basalt soil, abundant sunshine, and fresh mountain air, the region produces custard apples that are exceptionally sweet, fragrant, and highly sought-after across Vietnam.

2. Distinctive Features

- Shape: Round or heart-shaped with light green skin and evenly spaced bumps (“eyes”).

- Flesh: White, smooth, and soft with glossy black seeds; naturally sweet with no sharp acidity.

- Harvest Season: From June to September each year.

- Cultivation: Grown using VietGAP standards, minimizing chemical use to ensure clean, high-quality fruit.

3. Key Growing Areas

- The communes of Chieng Mung, Chieng Ban, Chieng Chung, and Hat Lot in Mai Son District – the largest custard apple-producing area in Son La, with over 1,000 hectares under cultivation.

- Many farmers and cooperatives apply modern techniques like fruit bagging and drip irrigation to improve yield and appearance.

4. Nutritional Value & Uses

- Rich in vitamin C, B6, potassium, and fiber, promoting digestion and boosting immunity.

- Enjoyed fresh or processed into smoothies, jams, dried fruit, or custard apple syrup.

- Suitable for all ages due to its mild, naturally sweet taste.

5. Where to Buy

- Fresh from the orchards in Mai Son during harvest season.

- Through clean agriculture cooperatives, OCOP booths, or major e-commerce platforms.

- Processed products like dried custard apple, jam, and syrup are increasingly popular in domestic and export markets.