What Is A Bosc Pear: Bosc Tree Growing Conditions

By: Bonnie L. Grant, Certified Urban Agriculturist

Pear lovers know the classic flavor of a Bosc pear and will accept no alternatives. What is a Bosc pear? Unlike most pear varieties, Bosc sweetens early so you can enjoy the fruit almost from picking. Usually, harvesting Bosc pears starts in early to mid-fall, and the fruit will last well into winter with proper storage.

What is a Bosc Pear?

Bosc pears were introduced in the early 1800s. This meansthey have been part of our diet for some time and are firmly entrenched as oneof the tastiest of pears. It is unclear if the variety is Belgium or French inorigin but it is a late season producer, often called a winterpear. Cooler regions of the country are perfect for Bosc treegrowing. Some tips will help you learn how to grow Bosc pears.

Boscs develop sweeter flavor while on the tree and do notneed as much cold storage time for wonderful flavor. If fruit is harvested veryearly, they will reach peak flavor in 14 days. The skin on Bosc pears is awonderful rust tone with mottling, while the interior flesh is creamy white,sweet and buttery. In fact, in some areas, the variety is called Buerre Bosc.

Other names include European pear, Kaiser Alexander andCalabasse Bosc. The trees were first commercially grown in the eastern UnitedStates but are now primarily commercially grown in the Pacific Northwest.

How to Grow Bosc Pears

You will need a full sun location with well-draining soiland end of summer cooling for best Bosc tree growing. A Bosc pear tree is easyto cultivate once established.

Use a stake when the tree is young to train it straight and prunethe pear tree annually to promote a strong scaffold form. Prune eachbranch by a third in spring to help the plant achieve a nice open vase shape. Asthe tree begins to produce fruit, some may have to be removed early if clustersare too thick. This will allow other fruits to mature fully.

Fertilize the plant in spring by spreading well-rottedmanure around the root zone. Watch for pest and disease issues and combatimmediately.

Tips on Harvesting Bosc Pears

You may want to wait to see if your Bosc pears turn aprettier color or become soft to the touch, but don’t. The leathery skin andcinnamon brownish cast are a natural part of this variety. The greenishundertones will become subtly more yellow when fruit is ripe and the base ofthe stem may wrinkle a bit.

The best way to determine when to harvest is by checking theneck. Exert gentle pressure at the neck to detect if it is softening. The fruitcan be eaten right off the tree and will be sweet-tart, crisp and refreshing.You can finish ripening early pears by leaving them at room temperature. Onlyrefrigerate pears once they are ripe.

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Read more about Pear Trees

How to Grow Pears in your Home Garden

How to Grow Pears in your Home Garden

Growing Sugar Pears

This sweet fruit with spicy undertones is ideal for cooking and preserving

All pears are naturally sweet when ripe, but a proper sugar pear is the fruit of the ‘Seckel’ pear tree, a strong-growing, blight-resistant variety winter-hardy as far north as Zone 5. About half the size of a Bartlett or Bosc, sugar pears start green but show a reddish blush over russet skin at full maturity. Named for the 18th-century Pennsylvania farmer who introduced it, the fruit is very sweet with a spicy undertone, crisp when eaten out of hand and ideal for cooking or preserving.

Locate a pear tree carefully in the garden, choosing a sunny spot that’s sheltered from the wind. Plant one- or two-year-old saplings in early spring, in a deep, wide hole that’s abundantly supplied with organic matter in the form of compost and manure. The tree may be planted in the lawn but, if so, make sure that you leave a meter-wide circle of bare soil around it, mulching the ground with straw, lawn clippings, autumn leaves or aged sawdust or wood chips in order to suppress weeds, retain moisture and feed the roots over the course of time.

If rodents tend to be a problem in your garden, it’s a good idea to wrap a tree guard of some kind around the trunk to prevent any damage from animals. A weekly soaking during the growing months ensures that the small, perfect pears will grow as big as they can and your patience at

harvest time will be rewarded with extra sweetness.

How to Grow Pears

Planting varieties of Pears suited to your conditions is the best way to ensure that you’ll get a healthy harvest each season. It’s varieties because most pears are not self-pollinating that is, they need at least two different trees to pollinate and produce well (more on this in a moment). This isn’t a hardship. Who wouldn’t want two kinds of pears?

Available varieties include Asian types, European types, and hybrids of the two. The classic European pear varieties—’Bartlett’, ‘Anjou’, ‘Bosc’, ‘Comice’, and lately even ‘Seckel’— have become highly susceptible to a widespread bacterial disease called fire blight. They’re wonderful pears, suited to USDA Plant Hardiness Zones 5 to 8, but not the best choices for large swaths of the East and other regions where warm, wet springs—prime fire blight conditions—are the norm.

The good news for organic gardeners is the availability of fire blight–resistant varieties (though resistance is just that, not immunity). ‘Magness’ is an excellent choice, says Richard Bell, research horticulturist at the USDA/ARS Appalachian Fruit Research Station in West Virginia. This variety resists fire blight and yields sweet, fragrant fruit in early autumn. Just bear in mind that ‘Magness’ can’t be a pollinator and so needs to be planted with two other varieties, not just one other. Bell also likes ‘Moonglow’, ‘Potomac’, and ‘Blake’s Pride’.

Fire blight–resistant ‘Warren’ is the standard pear for the South, though it won’t do well in the Deep South. For Zones 9 and 10, aptly named ‘Flordahome’ is often recommended. Travis Callahan, southern pear chairman for the North American Fruit Explorers, likes ‘Louisiana Beauty’ (a.k.a. ‘Leona’), the best pear he grows in Abbeville, Louisiana. It’s hard to find in nurseries, but you can get graft wood from the National Clonal Germplasm Repository (info at www.nafex.org). For Zones 3 and 4 up north, Bill MacKentley of St. Lawrence Nurseries, in Potsdam, New York, suggests the small, ‘Seckel’-size ‘Ure’ or his own find, ‘Nova’, named for his daughter.

In the Northwest, where fire blight isn’t a problem but pear scab can be, ‘Rescue’ is a fine choice.

You can try growing the old favorites if fire blight is not prevalent in your area. Stella Otto, an orchardist in Maple City, Michigan, and the author of The Backyard Orchardist (Ottographics, 1995), is fond of the large, yellow, red-cheeked ‘Clapp’s Favorite’. Or try ‘Flemish Beauty’ and find out why it used to be the nation’s top commercial pear.

Size Matters

Standard-size pear trees reach 30 feet tall. Even if you have the room for a tree that size, the fruit from its upper branches can be hard to harvest. That’s why most home pear growers choose dwarf or semi-dwarf varieties. (Bonus: Smaller trees start bearing fruit sooner than full-size trees more on this in the next section.) Like most fruit trees, pear trees are typically grafted—the variety you choose is attached to a rootstock that determines the tree’s size.

The traditional rootstock for dwarf pears is quince, which produces a tree that is 8 to 10 feet tall. Not all pear varieties take to grafting onto quince rootstock. It is reliably hardy only to Zone 6, and it’s shallow-rooted and therefore less drought-tolerant.

Another option, especially in colder climes, is a semi-dwarfing tree, typically grown from rootstocks designated as ‘Old Home’ 5 ‘Farmingdale’ or OH5F. These rootstocks are hardier than quince and produce a tree 60 percent to 70 percent as tall as a standard tree. To find out which rootstock and variety combination is best for your growing conditions, look for a nursery in your region and ask questions before you buy.

Prepare Before Planting

Take time to have a spot for your trees carefully chosen and well prepared before they arrive. “Get the soil right,” Stella Otto advises, “then get the trees.” Pears are usually sold as one-year-old, unbranched “whips.” Dwarf varieties begin to bear fruit three to five years after the whip is planted semidwarfs produce a full harvest in five to seven years.

Plant pear trees in full sun and give them good air circulation and deep, well-drained soil that’s slightly acid (pH 6.4 to 6.8). Set them so the graft unions are 2 to 3 inches above the soil surface. Give each 5 to 10 pounds of composted manure to start mulch the trees generously and for a few years, be sure they get 1 inch of water a week either from rainfall or your hose.

How you feed and prune your trees will affect not only their size, shape, and yield but also their ability to withstand fire blight, which thrives on lush, new growth. Left to their own devices, pear trees will shoot straight into the sky. Add too much nitrogen to the soil, and you’ll only encourage vigorous, blight-prone, upward growth, which also will delay fruiting and diminish dwarfing. Prune too often, and the same thing will happen. You can train a pear tree so it has one central leader or main trunk, or you can keep two or three leaders, so you don’t lose the whole tree if fire blight strikes one leader.

“Put your pruners in the closet for the first few years and lock the door,” says James Cummins, an experienced pear grower and nurseryman in Geneva, New York. It’s far more important to frustrate the upright growth by spreading the branches each spring so they grow roughly 60? from vertical. Use a stick notched at each end to spread apart two branches, or hang a weight near the ends of branches to hold them down. Do this in spring, just after petal fall. Cummins also recommends using a spring-type clothespin to establish a wide crotch angle when shoots are about 6 inches long.

Prevention is the Cure

The big news in pear growing is kaolin clay, a superfine organic spray sold as Surround that coats pear trees in a thin, white protective barrier. The pear psylla, a small sucking insect much like an aphid, is the primary insect scourge of pears, largely because the honeydew left by the pests encourages the growth of sooty mold. Psylla adults simply won’t lay eggs on trees sprayed with kaolin, and the kaolin residue irritates psylla nymphs. Your trees will look like they’re dusty, but the stuff is harmless. It is so effective, says John Dunley, Ph.D., an associate professor of entomology at the Washington State University Tree Fruit Research and Extension Center in Wenatchee, that even the big nonorganic growers in his area are using it. Cover your trees through bloom, and ideally keep them covered across the growing season, Dr. Dunley says.

Codling moths affect pears less than they do apples, but they can be a problem in some areas. You can control them with nothing more complicated than religiously picking off damaged fruit and disposing of it, with the larvae still inside, thus disrupting the insect’s life cycle, says Bill Denevan, a commercial organic pear grower in Santa Cruz, California. Be sure to put it in the refuse pile, not your compost heap.

Fire blight is a bacteria that thrives especially in warm, rainy spring weather. Stella Otto follows the “65/65” rule of thumb: If the temperature is above 65°F and the humidity is above 65 percent, fire blight can develop. The bacteria typically enter the plant via the blossoms, as well as through breaks and damage. The tips of affected branches curl in the shape of a shepherd’s crook, and pustules that form on the tree may ooze infectious orange-brown liquid.

It bears repeating that the first line of defense is choosing blight-resistant varieties. Conventional wisdom advises you to prune off infected branches a good 8 to 12 inches below visible damage when you see it and then in winter cut off the cankers that house overwintering bacteria. Stella Otto recommends waiting until winter to cut out damaged branches you’ll be less likely to miss the full extent of the damage and less likely to spread the infection. It’s also a good idea to pinch off the extraneous blooms that appear after the tree’s primary bloom. Which is why you’ll see old pear growers pinch off stray blooms whenever they walk an orchard, as a matter of habit.

Pick of the Pears

The Classics (1)

Sweet, juicy, handsome dessert pear cold-hardy typically ripens in late September but needs two months’ storage to reach perfection.
Harvest time: Late

Picked green, ripens to yellow sweet, musky flavor the number-one commercial variety, but highly susceptible to fire blight. Will not cross-pollinate with ‘Seckel’.
Sweet, juicy, handsome dessert pear cold-hardy typically ripens in late September but needs two months’ storage to reach perfection.
Harvest time: Midseason

Hard, crisp, grainy flesh with russet-brown skin tolerates heat and cold grows in clay soil keeps for six months in cold storage.
Harvest time: Late

Luscious, buttery dessert pear round, with smooth, green skin, blushed with red good keeper pronounced cahm-EECE.
Harvest time: Late

Small, supersweet coppery red to a golden brown used to be considered resistant to fire blight, now considered susceptible. Will not cross-pollinate with ‘Bartlett’.
Harvest time: Midseason

Fire Blight-Resistant Pears (2)

‘Blake’s Pride’
Juicy, aromatic fruit and high yield combined with blight resistance introduced in 1998 by USDA and Ohio State University.
Harvest time: Midseason

Hybrid of ‘Seckel’ and ‘Comice’ sweet, highly aromatic the ideal combination of high quality and fire blight resistance needs two other varieties for pollination.
Harvest time: Midseason

Mild, delightfully sweet flavor smooth, nongrainy flesh similar to ‘Comice’ with not quite the quality but much better resistance to fire blight.
Harvest time: Early

Other Noteworthy Pears (3)

‘Clapp’s Favorite’
Light yellow skin, blushed red with russet flecks sweet, spicy, fine-grained flesh similar to ‘Bartlett’ in quality but similarly susceptible to fire blight.
Harvest time: Early

‘Flemish Beauty’
Excellent flavor and looks once the leading commercial variety but now highly susceptible to fire blight a great pear where blight isn’t a problem.
Harvest time: Midseason

Tendergreen skin, fine eaten fresh widely grown in Florida, as the name suggests, but can’t handle the cold.
Harvest time: Midseason

Large, round, melting, and juicy can be eaten green or ripe very hardy, a pear for the North.
Harvest time: Midseason

Elongated, with attractive orange and red stripes creamy smooth flesh resists pear scab great for the Pacific Northwest where pear scab is prevalent.
Harvest time: Midseason

A yellow pear for the North, from Canada small, ‘Seckel’-size fruit tree drops fruit but it remains good on the ground for days extremely hardy ‘Early Gold’ is a similar variety.
Harvest time: Early

Long-necked, with a reddish blush discovered in Mississippi the standard pear for the South.
Harvest time: Midseason

¹All are now very susceptible to fire blight (‘Seckel’ a little less so) and best grown in the cool, dry West and in other areas where fire blight is not a significant problem.
²The key to growing pears in the East and in other warm, wet areas where fire blight thrives is selecting a fire blight-resistant variety.
³These varieties merit attention for flavor, looks, and/or their suitability to a specific climate.

Ripe and Ready

Pears ripen from the inside out. Left to ripen on the tree, they may become mushy. Off the tree, however, they ripen quite nicely. Most pears are ready to pick when the small flecks on the skin, called lenticels, turn from white to brown and are slightly indented. To get your pears ready to eat, use this plan from John Dunley, Ph.D., a researcher and pear lover in Washington State. Store pears in a cool, dry place, such as a basement. A few days before you want to eat them, put a few in a bowl with bananas, which emit ethylene, a ripening agent. Dr. Dunley covers the bowl with plastic wrap. The pears ripen in two to four days. “The pears ripen faster,” Dr. Dunley says, “when I put the bananas on top of the pears—and the more bananas, the faster the pears ripen.”

Pear Care

Pears need soil with moderate fertility. Frosts during the bud and blossom period can damage the flowers and reduce yields significantly. Try to locate pears on a slope for better air drainage, or on the north side of a building to retard flowering. Space standard trees 20 to 25 feet apart, dwarf trees 12 to 15 feet apart.

Keep young trees weed-free, and water well during dry spells to help the roots get established quickly. Fertilize lightly in early spring of the second and succeeding years about 2 weeks before bloom. In moderately fertile soils, use ammonium nitrate at 1/8 pound or its equivalent per tree, multiplied by the number of years the tree has been set. Use less if you have highly fertile soil. If shoot growth on the tree is more than 12 inches in a season, use less fertilizer the following spring. If the leaves are pale green or yellowish in midsummer, add slightly more fertilizer the next year. Be careful applying fertilizer around your pear trees. Too much nitrogen promotes succulent growth, which allows fire blight disease bacteria to enter the tree's tender young shoots more easily.

Also, pears require several months to harden off in the fall. High nitrogen levels after mid-summer delay this hardening-off process. If your pear tree is located in a lawn area, cut back on turf fertilizer applications when you feed your lawn so as not to give your trees too much nitrogen.

Dwarf pears are often trained to a central leader. Semi-dwarf and standard-size trees also yield best when trained to a central leader, but they are usually trained to a modified leader because that form is easier to maintain with a larger tree. In an area prone to fire blight, you can prune your tree to multiple leaders. That way an infected leader can be removed while the others keep growing.

Pears are trickier to prune well than apples because all their branches grow nearly straight up. This growth habit promotes weak branches and dense foliage around the center of the tree, which encourages fire blight, fungus diseases, and pear psylla. Once you get the knack of pruning, the results will be worth the trouble. Prune regularly, though generally very lightly. Spreaders will help direct the tree's scaffold branches to a more outward, horizontal direction, and will encourage early development of fruiting spurs. Fortunately, pears are easier to train than most trees. Start in early summer of the first year. Toothpicks or clothespins can be used when branches are small later, use wooden slats with the ends notched in a "V" to hold them in place. Sharp ends of spreaders can poke into the trunk and branch slightly, but won't hurt the tree. (An alternative practiced by some growers in the West is to hold branches down with a string tied to a clip in the ground). Pears bear their fruit mainly from terminal buds on short branches or spurs. Mature trees need only light pruning during the dormant season, mostly to thin out unfruitful, diseased, or crowded branches.

Avoid heading back cuts during dormant pruning since this will result in new, long, unfruitful shoots. If you have a variety that bears at an early age, such as 'Bosc' or 'Bartlett', remove fruit developing on the ends of thin fragile branches to keep the limbs from breaking.

Pollination can be a problem with pears because bees are not partial to their blossoms pear nectar contains less than 10 percent sugar, compared to nearly 50 percent in apple nectar, and pears often flower when it's too cold (below 55° F) or wet for the bees to fly. To make matters worse, pear blossoms are fertile only for a short time. Pollination is most likely if the weather is warm during pear blossom time. If you're fortunate enough to live near an ocean coast or large lake, the cooling influence of the water in the spring promotes later blooming of pears and facilitates pollination. Ask other pear growers if pollination in your area is erratic from year to year if so, you may need a beehive when your trees are coming into their bearing years for consistent fruit set. Move it to within 50 feet of your pear trees when blossoming starts. Even with a beehive, you may have occasional years of near-total crop failure owing to frosts or poor flying weather for the bees.

Tree Fruit Pollination

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Amending Soil

While you can't do much to change your climate, soil amendments such as compost can improve drainage in clay soils and slow it down in sandy soils. In addition to altering the moisture retention of soil, amendments improve the ability of these soils to provide vital nutrients to pear trees. Rich soil provides the best medium for growth and fruiting. The University of California Agriculture and Natural Resources website recommends 1 inch of soil amendments for every 3 inches of soil.

Watch the video: Bosc Pear Tree Planting at Hollabaughs - Tamping

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