Tag Archive for: Guy Ames

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Apples and Pears: How to Tell When They’re Ripe

By Guy K. Ames, NCAT Horticulture Specialist

It’s the time of year when apple and pear growers are watching their trees like hawks. . .because the crows are watching the trees, too—like, well, crows.

Ripening fruit becomes attractive to crows and many other critters. The fruit sugars are just too much to resist. And beating the other critters to the fruit is one of the reasons you need to know when to pick. This is not always as clear as you’d think because, when it comes to apples and pears, there is ripe and there is “ripe.”

Ripe for the Picking

Pome fruits, apples, pears and quince, are “physiologically ripe” (the seeds are mature) sometime before they are their sweetest and before they begin falling from their parent trees. This is important because as soon as they are physiologically ripe they can be picked and expected to finish ripening off the tree! Fruit left on the tree past this first stage of ripening will continue to sweeten and change color and texture. There is nothing wrong with letting an apple reach peak sweetness on the tree. But doing so could compromise its firmness and storability. . .and it remains on the tree for the crows to find.

Pears, at least the European types, are a somewhat different story. European-type pears—like the familiar Bartlett and Comice—ripen best off the tree. This is not true for Asian pears, which ripen fine on the tree. If left to ripen on the tree, European pears generally start ripening from the inside out and can be grainy or mushy. These pears are best picked just shy of full ripe (but physiologically ripe) then chilled and “cured.”

Curing is simply a matter of allowing the pear to reach perfection at room temperature on your kitchen counter or table. If you’re in a hurry you can put the pears in a paper bag. Bag with a banana to further hasten the process. To check for perfect ripeness, hold the pear in your hand and push on the fruit near the stem area with your thumb. When the pear gives just a little to your thumb pressure it is ready to eat.

Follow the Signs to Ripe Fruit

But back to physiological ripeness and other indicators of ripeness. Here are some important indicators:

  1. The hanging fruit begins to change color. Even green apples like Granny Smith and most pears have a subtle color shift when ripening begins in earnest, but the untrained eye might not see it. But red apples will show a more obvious color shift from green toward red as they approach ripeness.
  2. Some fruit begins to fall. This is usually a solid giveaway, but it doesn’t mean that every fruit on the tree is at exactly the same stage. As fruit approaches maturity, a layer of tissue on the stem accumulates abscisic acid in preparation to drop the apple or pear. The grower can exploit this phenomenon to determine ripeness. Gently lift a fruit from the vertical hanging position to something approaching horizontal. If the fruit is ready, the abscission layer will break cleanly where it joins the twig or spur it is attached to.
  3. The seeds are hard and brown or black. This is the surest indicator of physiological ripeness because, after all, that’s what this whole thing is all about. The fruit gets sweet to attract creatures like us to eat it and spread the seeds. If the fruit gets eaten too early, before the seeds are ready, then the whole thing was for naught! Seeds that are soft and white are not ready and the fruit isn’t ripe. If you were to pick the fruit before the seed is mature, the fruit will not continue to ripen.
  4. The fruit pleases your palate. Hey, there’s no substitute for your taste. If you like it, then it’s ready!

There are four key indicators of ripeness in apples and pears.The professionals have other tools, like a starch test and a refractometer for measuring sugars, but even the pros will use the four other indicators listed above.

Storing Apples and Pears

If your intent is to store your apples or pears, then catching them right when they are first physiologically ripe will allow you to take these fruit while still firm and store them. Sometimes they will last for months depending on what you might have to keep them cool.

Interestingly, it could be argued that pome fruits are still very much alive after picking. They are still respiring (exchanging gases like oxygen and ethylene) and starches are continuing to convert to sugars. We’ve already mentioned that European pears reach their highest flavors after storage and curing. Similarly, many apple varieties don’t achieve their finest, most complex flavors until they’ve been stored for a while.

Happy eating!

Additional Information on Apples and Pears

For more on apple and pear production, see the ATTRA Sustainable Agriculture publications Apples: Organic Production Guide and Pears: Organic Production. You’ll find many other resources on fruit production on the ATTRA website’s Fruits page, including publications, podcasts, and videos.

Guy has written several blog posts on the joys and challenges of fruit production. His previous posts include Pear Trees Exemplify Resilience, Restorative Pruning, Dwarfing Apple Rootstocks: Pros and Cons, Fall Planting Fruit Trees, and Battling Borers in Organic Apple Production.

You can contact Guy or other NCAT agriculture specialists by email at askanag@ncat.org or 800-346-9140.

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Peach Leaf Curl

By Guy K. Ames, NCAT Horticulture Specialist

In Northwest Arkansas I’m seeing peach leaf curl in my orchard. It’s April, but the calendar date is not as important as the growth stage of the peaches. The professionals call this time “shuck split.” The “shuck,” or the last remnant of the flower, is splitting and falling from the growing young fruit. This is a crucial time for the developing fruit as it is growing rapidly, and this is not a good time for the tree to be stressed. This disease, incited by the fungus Taphrina deformans, causes the leaf to deform and swell irregularly (see photo). As you can imagine, leaf function—primarily photosynthesis and respiration—suffers and the tree is stressed. The more severe the curl (the more leaves are affected), the more stressful it is to the tree.

Managing Peach Leaf Curl

You’re going to want to do something about it, but there’s not much you can do once you see it on your trees other than to remember to spray next year during dormancy. Here’s why. The fungus overwinters in the tiny crevices around the leaf scale (or leaf bud). As soon as the leaf bud begins to swell in the early spring the fungus invades the leaf tissue. That’s right, the fungus is inside the leaf and thus protected from normal fungicide sprays! You should apply sprays of lime-sulfur (the best organic fungicide for this disease) sometime in March before the leaf buds begin to swell. If the trees have gone through severe infection, you can apply once in November when the leaves have fallen and then again in the spring before the new leaves emerge.

Helping an Infected Tree

A tree with a severe infection will sometimes drop all its infected leaves and try to push a new crop of leaves. This is understandably stressful for the tree, so if it happens, the grower could help the tree out by applying a quick release fertilizer of some sort. Organic growers could choose compost tea or fish emulsion. If the infection wasn’t severe (only a small percentage of leaves were infected), then you may need to do nothing. There is only the single infection period, so newly emerging leaves will be safe from T. deformans.

There are a few somewhat resistant varieties, including Clayton, Candor, and Frost, but this resistance is only relative to other more susceptible varieties and often can’t be relied upon for control.

Here’s hoping your leaves aren’t curly!

More Information

Guy shows examples of peach leaf curl and the leaf buds where the fungus overwinters in his video What is Peach Leaf Curl? on ATTRA Sustainable Agriculture’s YouTube channel.

For more on peach diseases, see the ATTRA Sustainable Agriculture publications Peach Diseases Identification Sheet and Peaches: Organic and Low-Spray Production.

Contact Guy and NCAT’s other agriculture specialists by emailing askanag@ncat.org or calling 800-346-9140.

Restorative Pruning

It Takes More Than a Nip and a Tuck, but You Can Bring Those Old Trees Back Into Production

By Guy K. Ames, NCAT Horticulture Specialist

Long-neglected fruit trees quite often simply die of disease or trunk borer damage, especially in the South where I live.  But if they don’t die, one of the two most common problems with aging fruit trees is growth so tall that the thought of pruning and harvesting them just seems impractical and intimidating.  The second most common problem is that old, overgrown trees tend to become unproductive, especially of good quality fruit.  “Restorative pruning” or “rejuvenative pruning” are terms used to describe techniques to bring old, too tall, and unproductive trees back to a manageable and productive state.

A Central Principle

Ideal central leader form. Illustration courtesy Guy Ames.

Starting with the tree that is simply too tall to efficiently manage, we must first determine what the natural growth habit of that tree is.  Apples, pears, and—to a slightly lesser degree—sweet cherries naturally assume a more-or-less pyramidal form, with one so-called “central leader” taller and stouter than any other upright growing shoot.  Such trees are described by horticulturists as exhibiting “apical dominance,” meaning the apex or top of the tree dominates the growth pattern of the overall tree.  When this natural growth habit is violated—that is, when the central leader is cut back to any significant degree—the tree will likely respond by sending up many, many candidates to be the new leader.  It’s like a king or queen that dies without heirs.  Many pretenders to the throne will arise!

And the further down the trunk you cut the central leader, the more these vertical shoots proliferate and the more vigorous these shoots will be.  They will crowd the center of the tree, blocking sunlight and air. Such vertical shoots tend not to be fruitful.  So, then, the first principle to respect in bringing down the height of a central leader-type tree (apples, pears, and sweet cherries) is to not try to cut out too much at once.  Don’t try to cut a 30-foot tall apple tree down to 12 feet in one fell swoop!  Plan for a two, three, or four year process, depending on the size of the tree currently.

The Modified Central Leader System

Modified central leader cut. Illustration courtesy Guy Ames.

At the same time and just as important, when you’re cutting back the central leader, pick another more-or-less upright growing shoot to become the new central leader.  This new central leader will probably arise from the same main trunk. It should be a few feet shorter than the leader you cut out.  Once you’ve chosen the new central leader, other serious contenders for tallest shoot should be cut back, preferably to a more horizontal growing limb.  This pruning/training system is called “the modified central leader” system. That, or the “multiple central leader” system (see below), should be the way you maintain the desired height of a fruit tree once it first reaches the desired height.  In other words, you will probably be choosing a new leader each year after the tree reaches the height you want.

The Multiple Leader System

When you’re faced with a very large, old tree, a new central leader may not be enough.  In such cases, choosing multiple leaders might be the best choice.  In essence what this will look like is three or four “secondary trees,” all growing and contained in the canopy space of the original, single tree.  Instead of having one big pyramidal tree on one big trunk, you’ll have two, three, or more secondary trunks branching off of the main trunk.

Each of these secondary trunks, then, will have its own central leader, resulting in multiple leaders for the tree as a whole.  To be honest, it’s probably rare that such a tree ever looks perfectly balanced among the several secondary trees. That is not important.  What’s important is that you maintain the trees “need” for apical dominance among these several secondary trunks. If you don’t choose a leader or leaders yourself, the tree will waste energy and crowd the interior of the tree with multiple wannabe leaders.

Big Thinning Cuts

The sheer amount of wood in an old tree can be intimidating!  For this reason alone, after choosing the new leader(s), you will serve your purposes best if you focus on removing a few big branches.  An important—maybe the most important—purpose of pruning is to thin out the interior of the canopy for sunlight and wind penetration.   An old rule of thumb is that a full-grown robin should be able to fly through the tree’s canopy.  Removing any large branches that are growing straight up (not including the central leader!) or back into the center of the tree is a good place to start.  And making thinning cuts rather than heading cuts will make your work lighter next year and the year after that.

To fully understand the distinction, especially the tree’s response to these different types of cuts, refer to ATTRA’s Pruning for Organic Management of Fruit Tree Diseases.  But basically a thinning cut is cutting a branch or shoot back to where it joins with another branch or the trunk.  In other words, where a branch forks, take off one fork, usually the one growing the most upright or back into the interior of the tree.  To repeat, restorative pruning relies on opening up that tree, so stand back and look at the tree. See if you can choose a few—three or four—large branches that will open up the tree but still leave the tree looking balanced.

Patience and Persistence 

The author points to a profusion of “water sprouts,” new, upright-growing sprouts caused by cutting back the central leader.

Patience and persistence are the next things you will need to bring these old trees back to a manageable and productive state.  Even if you do a good job picking a new central leader or multiple leaders, in the first year and with the first main cut(s), the old tree is almost certain to produce an abundance of upright growing shoots sometimes called “water sprouts.”  You will have to be patient and persist in pruning out those upright growing sprouts. Manage this tree to satisfy the criteria leading to good fruit:  thin out the interior of the tree for sunlight and air penetration, favor outward-growing limbs and shoots, and always remove diseased wood and branches that are rubbing against each other.

It might take three or even four years before the tree is in a more manageable state and back to producing large, quality fruit. But once and well done, the tree will be back to something much more easily managed and almost certainly more productive.

Find Out More

To learn more about pruning, see the ATTRA Sustainable Agriculture videos Pruning Fruit Trees: Tools and Tips and Pruning Fruit Trees: An Introduction. Feel free to contact the ATTRA help line at 800-346-9140 or email askanag@ncat.org if you have questions. We’re here to help!

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Juneberry: the Delicious Native American Fruit with a Thousand Names

By Guy K. Ames, NCAT Horticulture Specialist

At right: Juneberry fruits look quite like medium-sized blueberries, but the juneberry is actually much more closely related to apples and pears. Photo: Guy Ames, NCAT.

Of the many names for this plant, “chuckleberry” is certainly my favorite, but I’ve only seen it in writing, never heard it spoken. Around the Ozarks where I live “sarvis” or “sarvisberry” seems to be the most commonly spoken, at least among the old-timers. If a name is known at all for this berry among the newcomers to the Ozarks, “service” replaces “sarvis.”  “Sarvis,” I think, is presumed to be a thick southern linguistic variant of “service.” “Shadblow” and “shadbush” seem to me to be the weirdest names, but they are documented and widely used at least in coastal regions. (Shad is a once-common fish whose annual spawning runs up the rivers of colonial New England happened to coincide with the early springtime blooming of this tree.)

What’s in a Name

Other names include saskatoon, juneberry, blueberry tree, chuckley pear, and, of course, the Latin binomials of which there are several because within its genus, Amelanchier, there are several species. All of the species produce berries nearly indistinguishable from the others. And all these names, except and very notably the saskatoon, pass over the Native American names, which were presumably many because Amelanchier grows over a wide area and commended itself to all who ate it.

When I first moved to the Ozarks in 1971-72, the sarvisberry trees (as I first learned to call them) were the first bloomers that I would notice on the dull gray wooded hills of the Ozarks in February. In their profusion of bright, white blooms they were a welcome harbinger of spring. One probably erroneous explanation for the origin of “serviceberry” is that the blooming of the tree indicated that the soil was thawed enough to dig graves and hold services for the folks who didn’t make it through the winter.

Although it is improbable, the funereal explanation persists and I rather enjoy it. Like Persephone returning from Hades every spring, it presents a beautiful and poignant reminder of the rebirth part of the never-ending cycle of life and death.

Speaking of death, a juneberry pie or cobbler is to die for! When eaten fresh, the juneberry has a detectable almond flavor that comes from its small, edible seeds. But when cooked into pies or cobblers, that almond aroma becomes pronounced and will fill a kitchen and spill deliciously into the house!

Mistaken Identity

A juneberry bush full of white blossoms.

A juneberry bush in bloom. Photo: Margo Hale, NCAT.

When you first see a juneberry fruit you might have a hard time distinguishing it from a medium-sized blueberry. However, the juneberry, technically a pome fruit, is much more closely related to apples and pears than to blueberry. A few intrepid grafters have even had limited success grafting pear wood onto juneberry (graft compatibility is an indirect proof of relatedness).

Sometimes the juneberry is referred to as a tree, sometimes a bush. That difference is not just in the eye of the beholder. The species native to the Ozarks, A. arborea, like the species name suggests (arborea = tree), assumes the form of a small tree. The species that I prefer for fruit production and endemic to most of the Northeast United States, A. canadensis, is a multi-stemmed bush usually around 12 ft. tall. The saskatoon, A. alnifolia, native to the Northern Plains and into the foothills of the Canadian Rockies looks like a shorter version of A. canadensis. It usually tops out around 6-8 ft. Regardless of species, the fruit looks and mostly tastes the same.

Juneberry’s Uses

Though the Native Americans used the juneberry wherever it grew (pemmican was one way the juneberry was preserved and used), until relatively recently it has not been pressed into commercial service. That is beginning to change. The University of Saskatchewan is conducting research and breeding to commercialize the saskatoon, A. alnifolia. And in the United States, Cornell University Extension has done some limited research and promoted juneberries as an alternative to the persnickety blueberry. In Canada there is a nascent saskatoon industry marketing frozen and canned saskatoons as well as wines, jams and jellies made from saskatoons.

Whatever they’re called, they are easy to grow. They’re not nearly as finicky as blueberries regarding soil pH and watering. And, if you get the right species for your area, you’re not likely to have any disease problems (I and other growers in the Ozarks have found A. alnifolia or saskatoon to be susceptible to cedar-apple rust). And though they bloom very, very early, the blooms never seem to be damaged by late spring freezes and frosts. I have juneberries year after year, often in years that other fruit crops are wiped out by weather or disease.

A woman holds a basket of ripe juneberries in her left hand and a basket of ripe mulberries in her right hane.

Juneberries (left) and mulberries ripen at the same time—in May, not June! Photo: Guy Ames, NCAT.

As with most small berries, the commercial viability of juneberries will revolve around harvesting costs. In Canada, researchers hope to find techniques and cultivars that will lead to the uniform ripening that allows mechanical harvesting. Elsewhere and until that happens, individual farmers will have to figure out ways to efficiently pick and effectively market the fruit to make juneberry production a viable money-making proposition. But that should not preclude gardeners and homesteaders from planting these easy-to-grow and highly productive berry plants in their gardens for home use.

Related ATTRA Resources

Fruit Trees, Bushes, and Vines for Natural Growing in the Ozarks