The Bradford pear, known botanically as Pyrus calleryana, is a flowering ornamental shade tree prized for its reliable and abundant white blooms that appear each April and May. Environmental conditions and age affect a Bradford pear tree's bloom capacity most profoundly. Bradford pear trees will bloom only after they reach maturity, which can be five years or many more, according to the Purdue University Plant and Pest Diagnostic Laboratory. Beyond maturity, perfecting the soil fertility, and moisture level, and preventing competition from weeds and other plants, will boost the chances of lush spring blooms.
Water your Bradford pear tree regularly and deeply, either by rainfall or by applied irrigation. Keep the soil evenly moist at all times but not soaking wet. Water generously to soak the root zone to a depth of at least 1 to 3 feet down, where most roots reside. Water young trees more frequently, such as once per week, and older trees every two to four weeks depending on the season and weather conditions.
Fertilize your Bradford pear tree once or twice each year with a complete, balanced fertilizer such as a 20-20-20 or similar ratio. Following the product label dosing directions and make applications in late winter and early summer. Trees grown in rich soil that is amended with compost and aged manure will require little or no fertilizer, while trees grown on poor-quality fill soil will need more. Underperforming trees with little annual lateral branch growth or thin foliage may be stunted by poor nutrition. Cast fertilizer over the surface of the soil starting a foot out from the trunk and extending a foot past the outer drip line of the tree's canopy. Water the fertilizer in well after feeding.
Spread several inches of organic mulch around the tree each year. Use compost, leaf mold or shredded bark to feed the soil, hold moisture in and keep weeds and other competitive plants at bay. Pull any weeds and emerging plants up when you see them and before laying down your annual blanket of mulch.