When to Pick a Mango: Shoulder Fill, Cutting the Stalk and the Sap That Burns

Color is the least reliable sign

Mangos do not have to color up on the tree to be ready, and many are fully mature while still largely green. Waiting for a red or yellow blush produces fruit that either falls, splits, or arrives at the kitchen already going over. What you are judging is maturity, meaning the fruit has finished filling and will ripen properly once picked, and that shows in the shape long before it shows in the skin.

The clearest sign is the shoulder. On an immature fruit the stalk end slopes away from the stalk in a continuous line. As the fruit matures, the shoulders fill and lift until they are level with or above the point where the stalk joins, and the beak, the small pointed lip on the lower side, becomes plump and rounded. Run a hand over the stalk end: when it has gone from sloping to level or slightly raised, the fruit is ready.

The flesh color under the skin confirms it. Cut one fruit as a test: if the flesh next to the stone has turned from white to cream or yellow, the whole tree's crop of that age is mature. This test costs one fruit and settles the question, and it is worth doing every season until you can read the shoulders confidently.

The other useful cues are the bloom, a dusty waxy film that develops on mature fruit, a change from angular to full and rounded in cross-section, and the first fruit dropping without wind or damage. When sound fruit begins to fall of its own accord, the rest of that batch is ready.

The sap burns, and it burns the fruit too

Mango is in the same family as poison ivy and cashew, and the milky sap that spurts from a broken stalk carries the same class of irritant compounds. On skin it causes a delayed rash, redness, blistering and itching that appears hours after contact and can last a week or more. People sensitised by repeated exposure react more strongly each season, and the sap can reach the eyes if a stalk snaps under tension and flicks. Anyone who reacts to poison ivy should assume they will react to this.

The same sap damages the fruit. When a stalk is pulled or snapped short, sap runs down the shoulder and burns the skin of the fruit itself, leaving dark, sunken streaks that appear within a day and become entry points for rot. This is why commercial fruit is harvested with a length of stalk left on and de-sapped away from the fruit surface, and it is the single most useful harvest technique to copy at home.

Wear long sleeves and gloves, and do not harvest in shorts under a tree where sap will drip. Wash any splash off skin immediately with soap and plenty of water; the compounds bind to skin within minutes, so speed matters more than thoroughness. Keep the sap out of the eyes above all, and if it does get in, flush with water and seek medical advice.

1. Cut, never pull Use snips or a picking pole with a cutter and leave one to two inches (3-5 cm) of stalk attached. Pulling tears the stalk out of the fruit and releases a jet of sap over the shoulder and over your hands.
2. Hold the fruit away from you as you cut Sap comes out under pressure and travels further than you expect. Keep the cut end pointed away from your face and from the fruit already in the basket.
3. De-sap upside down Within a few minutes of picking, trim the stalk back to about a quarter inch (5 mm) and stand the fruit stalk-down on a rack or a tray of newspaper so the sap runs out and away rather than down the fruit. Leave it half an hour, then wipe the stalk end.
4. Rinse the shoulder if sap has run If sap has already tracked down the fruit, wash that area promptly with water and a little detergent. Left on, it burns a dark sunken mark into the skin within a day.
5. Handle as if bruises will show later Mature mangos bruise invisibly and the damage appears as the fruit ripens. Lay them in a single layer rather than dropping them into a bucket, and never stack picked fruit more than two deep.
6. Pick over several visits Fruit on one tree does not mature together. Take the fullest-shouldered fruit each time and come back every few days over two or three weeks rather than stripping the tree at once.

Never pick by shaking the tree. Fruit that hits the ground bruises, splits at the beak and rots at the point of impact days later, and the crop you have waited five months for is spoilt in a moment.

Ripening off the tree, and what late picking costs

Mature mangos ripen well off the tree and that is how they are best handled. Keep them at room temperature, around 68 to 77F (20-25C), out of direct sun and spread in a single layer with air around each fruit. They take three days to a fortnight depending on how mature they were at picking. A paper bag, or a bag with a ripe banana in it, concentrates the ethylene the fruit produces and speeds it up considerably.

Judge ripeness by feel and smell rather than by color. A ripe mango gives slightly under gentle pressure at the stalk end, in the way a ripe avocado does, and smells sweet and resinous at the stalk. Skin color continues to be unreliable right through ripening; plenty of fruit is fully ripe while still green over most of its surface.

Once ripe, fruit keeps in a refrigerator for about five days. Do not refrigerate unripe mangos: below roughly 50 to 55F (10-13C) they suffer chilling injury, which shows as gray patches, pitted skin and flesh that never softens properly and never develops flavor. This is the commonest way a home-grown crop is ruined after a successful harvest.

Leaving fruit on the tree too long has its own costs. Overripe fruit splits at the beak, attracts fruit flies and birds, drops and bruises, and softens on the tree into flesh that is fibrous and flat rather than sweet. Latent anthracnose also has longer to establish. Picking mature but firm and ripening indoors gives better fruit than tree-ripening in almost every garden situation.

Record the date each panicle flowered and the date you picked fruit from it. The interval from flowering to maturity is remarkably consistent for a given tree in a given climate, and after two seasons that number tells you when to start checking shoulders instead of guessing.