February 27, 2015
On a warm, sunny day you suggest a picnic under the pome tree.
“What is a pome tree?” your friend asks.
Pome fruit develops from the swollen base of a flower integrating the receptacle into the lush fruit surrounding it. Most likely, you can now name three pomes: apple, pear and quince. Long revered by ancient cultures including Greek, Roman and Chinese, pomes have striking, white to pale pink flowers making beautiful, and practical additions to our home gardens.
Pomes thrive best in temperate climates that have at least 1,000 hours of winter chill and moderate summer temperatures. UC scientists divide the state of California into six climate zones with Marin County in the North Coast, the wettest region of California. Here, rainfall averages 25 to 80 inches, with pome tree growth beginning in spring and slowing down in fall after harvest as length of day and temperatures decrease and dormancy follows.
Pomes awaken from dormancy when sufficient cold temperature (winter chill between 32 and 45 degrees) breaks down inhibiting growth hormones. As bloom occurs, bees are attracted and pollinate pomes.
Fruit ripens from late July through late fall and should be harvested by pulling the fruit up toward the branch. While apples ripen on the tree, pears ripen better off the tree in a cool spot and are ready to eat when the flesh near the stem yields a bit. Quinces are ripe when they turn yellow; they must be cooked to eat.
There are thousands of pome varieties but only a small percentage have been cultivated into the good-sized, juicy fruit we enjoy. The best time to plant is during the dormant season, January through March. To select and plant the best variety, consider site space, cross-pollination needs, winter chill requirements and fruit preference.
Because pomes do not grow true from seed, cuttings are grafted onto rootstocks selected for disease resistance, hardiness and tree size. During dormancy, prune 15 percent to 20 percent of last year’s growth to allow light and air into the center removing crossed limbs as well as water sprouts and suckers. Remember, sun exposed wood remains fruitful.
Cultural practices can help control pests and diseases. These include picking all fruit, raking leaves and fertilizing only in summer.
Natural predators such as lacewings, beetles, praying mantis and pirate bugs also help contain pests. Fire Blight is a serious bacterial disease of pomes. Cut out diseased wood and clean tools before and after with alcohol. To reduce coddling moth (results in wormy fruit), practice orchard sanitation described earlier, hang purchased pheromone traps and/or make your own attractants; recipes are online. To reduce scab infections and mildew, remove fallen leaves and fertilize only in summer. For more information on disease management, please refer to ipm.ucdavis.edu.
In Marin, irrigation requirements vary according to weather and soil conditions. Deeply irrigate at the drip line well away from the trunk especially during fruit development. Research indicates the best time to fertilize established trees is in summer when actively transpiring leaves uptake nitrogen. Either apply four inches of organic compost annually in summer or apply nitrogen fertilizer following label recommendations and then water well. Visit your local nursery and look for the best varieties to plant in Marin.
To learn more about fruit tree grafting and propagation, you can register for a March 7 seminar at Indian Valley Organic Farm and Garden. Presenters are John Valenzuela, chair of the Golden Gate Chapter of the California Rare Fruit Growers Society, horticulturist, consultant and educator specializing in permaculture and fruit trees, and John Heenan, a backyard rare citrus grower who volunteers in the Indian Valley Organic Farm and Garden fruit tree nursery and orchard.
Pome trees are a sure bet to provide habitat and nectar for bees, attractive accents in the landscape, fruit and a shady spot for a picnic.