Peaches are desirable for their soft, juicy flesh and sweet flavor. Sometimes called the queen of fruit, they are at their best when plucked straight from the tree. In fact, peaches don't ripen once they are removed from the tree, according to Texas A&M's AgriLife Extension website. For that reason, the amount of time peaches take to ripen depends specifically on the type (cultivar) of peach tree.
Different types of peaches ripen at different times. Early-ripening varieties, such as Springcrest and Junegold are harvested in mid- to late May. These peaches take only six to eight weeks to ripen. Others take much longer. Late-ripening varieties, such as Redskin and Jefferson are not ripe until late June. In general, most varieties are ready to be harvested in late June and early July, which means it takes them about 11 to 12 weeks to ripen.
Environmental conditions also affect peach development. Peaches planted at higher elevations may take an extra week to 10 days to ripen. Trees that are shaded will also have peaches that take longer to ripen. The more sun the peaches are exposed to, the faster they will ripen. Too much or too little water will also adversely affect the developing fruit. The same is true of fertilizer. Peach trees that do not get enough nitrogen will develop fruit that does not ripen well, resulting in small, sour-tasting peaches.
Due to the factors affecting the ripening of peaches, many home gardeners watch for signs of ripeness rather than relying solely on standard harvesting dates. Ripe peaches smell fresh and have soft flesh that gives slightly. The skin is red and yellow, not green, and the peaches have a plump, round shape. Some peach cultivators use an instrument called a penetrometer to determine when peaches are ripe. This instrument measures how soft the fruit is. Peaches often ripen at different times even on the same tree. Peaches on the outside of the tree (those exposed to the most sunlight) may be ripe up to 10 days before peaches on the inside of the tree or on the lower branches.
Thinning is vital for good fruit production. Thinning that is done too lightly will result in peaches that do not ripen properly, according to Clemson University's Cooperative Extension website. Thin the young fruit about a month after the tree's peak bloom by quickly twisting them off the branch. Hold the branch firmly so that you do not break it, and leave about 6 inches between each developing peach.