DC Urban Gardeners

Fruit Trees for the DC Area

By now we're all convinced of the many great reasons to grow our own food, like better taste and nutrition, saving money, avoiding long-distance shipping, and knowing exactly what's in the food we eat.  But growing fruit trees in Mid-Atlantic humidity can be a challenge, especially if you're a low-maintenance gardener. 

First there's the regular pruning that fruit trees need if they're to produce fruit you can reach or in some cases, produce fruit at all.  It's a lot more complicated than no-brainer pruning like hacking back to a uniform height; it means opening up the branch structure, for example, and that takes some skill.  So how to learn?  You can ask the person who sells you the tree for guidance, and some mail order suppliers provide care guides that describe the pruning required.  If all else fails, research online because pruning is a must.

But Cindy Brown, edibles expert at Northern Virginia's Green Springs Garden, warns growers not to rely too much on pruning, saying that reducing overall size is the worst reason to prune.  She believes it's far better to choose a plant that's the right size for where it's growing, and prune for other reasons - to improve health and productivity.   She also recommends starting the pruning process when the plant is young rather than trying to rejigger its shape later.

The good news for suburban gardeners is that so many fruit trees are dwarf in size and fit well in smaller gardens, even in pots on a patio.  Most need lots of sun, though, for health and productivity, and that means six hours a day.

Here are the most popular fruit trees for the D.C. area, starting with the easiest to grow.  They can be planted as soon as the ground is diggable in March.

Figs 
The easiest fruit tree in this area is undoubtedly the fig, which will fruit with as few as four hours of sun per day, is fairly pest-free, and can be grown as a shrub, a small tree or a large one. Washington Gardener editor Kathy Jentz describes figs as easy to propagate and "fairly low-maintenance compared to other edibles."  No spraying is needed, and deer avoid them.  They do require winter protection, at least for their first few years (for example, by planting them close to a building or wrapping them in burlap).  Jentz warns that "Your biggest challenge will be fighting the birds and squirrels for their bounty." And if wasps and yellow jackets arrive to devour the ripe fruit, hang a trap for them.  One supplier recommends adding lime around the base in spring, summer and fall.

Cindy Brown is also a big fan of figs, adding that they're "sumptuous in recipes and absolutely delicious!"  But that's not all - they're full of vitamins and have a higher fiber content than any other fruit, can be eaten fresh or frozen, dried, or made into preserves.  The best varieties are ‘Brown Turkey', ‘Celeste', ‘Marsailles' and ‘Hardy Chicago'.   

Pawpaws
These native trees do well in our area, are beautiful in bloom and yield fruit in three to eight years after planting.  At least two are needed for pollination, and these 40-foot trees are not for tiny patio gardens.  Some local gardeners avoid pawpaws because of their reputation for attracting raccoons but Michael at Edible Landscaping tells me that raccoons can be avoided by picking up the ripe fruit as soon as they land on the ground - that very morning.  And according to Scott Aker of the National Arboretum, Japanese beetles may occasionally damage the leaves, but pawpaws have no serious pest or disease problems and rarely need to be sprayed.  Fortunately, deer avoid them because of the bitter compounds found in the twigs.

Most sources say that pawpaws require full sun to fruit but should be shielded from the sun for their first two years, and Aker suggests building a small frame with stakes and covering the top with a piece of burlap or erosion-control fabric to provide the temporary shade needed.   (But then a local supplier tells his customers to just plant pawpaws in full sun and leave them be, so choose your advice.)  Aker also says it's essential to provide the young trees with consistent moisture in their first year.

And this is interesting, also from Aker: "Sometimes pawpaw trees fail to fruit even if another pawpaw is planted close by. The flowers, which appear in early spring, are flesh-colored and carry the faint odor of rotting meat. The smell may not be strong enough to attract the blowflies and carrion beetles that typically pollinate pawpaws. If your pawpaws flower but do not set fruit, you may want to try placing a piece of meat in the vicinity of the trees to draw flies at the time the flowers are open."  Who knew?

Asian Persimmons
Kristi Janzen at Edible Chesapeake Magazine had great success with an old persimmon tree that eventually outlived its productive lifespan, so she recently planted a ‘Saijo' for its small, elongated fruit and a ‘Hachiya' for its rounder, larger fruit.  "They require almost no care, and do well in the climate around metro Washington, DC."  She also explained that Asian persimmons are more popular than the American ones because they bear larger fruit and the trees themselves are much smaller and fit into urban gardens.  Also, unlike American persimmons, they don't need male and female trees to produce fruit.  She advises "waiting until they're ripe - that is, when they are soft to the touch, almost like an overripe tomato.  Only then will they be sweet and delicious.  Persimmons can also be dried."

Cindy Brown also loves Asian persimmons, adding that they're rarely bothered by pests.  Persimmons range in size from 15 to 40 feet and will fruit in two to three years after planting.

Peaches and Apples
Members of the rose family, peaches and apples are showy but suffer from damage by insect pests and persistent fungal disease in our humid summers, which problems are particularly frustrating to local gardeners hoping to avoid spraying with pesticides.  In fact, local experts say that the only way to grow them successfully is to spray regularly.  Commercial growers use systemic (and nonorganic) fungicides that remain after a rain but organic-only products must be reapplied regularly plus after each rain.  It may be the lack of that strict regimen of spraying that accounts for the failure of so many organic gardeners to successfully grow peaches and apples.

But whether you choose an organic or nonorganic pesticide, make sure it's formulated specifically for crops.  One organic insect-deterrent recommended by Edible Landscaping is the clay-based product Surround, which prevents insects laying eggs on the fruit.  To keep birds and squirrels from eating your crop, netting is the only solution.  And one local gardener told me that her Jonathan apple crop is routinely ruined by worms, despite her best efforts with organic pesticides.

Peaches seem to fare better because pest-resistant varieties are fairly successful, even in our area, though one grower told me that a particularly wet year can ruin a entire peach crop.  Overall, a little attitude adjustment goes a long way in growing apples and peaches - learning to accept blemishes and some insect damage.

Cherries
With cherries, too, a wet year can ruin the crop, and here in the suburbs, birds are the biggest pest growers have to contend with.  In selecting a variety, check whether it self-pollinates or requires a mate, and also its ultimate size because some grow to 40 feet.  For small gardens Kristi Janzen recommends ‘Northstar,' for sour pie-making cherries and ‘Krymst' or ‘Geisla' for the sweet ones.

Asian Pears
The staff at Behnkes Nursery tell me that along with figs and persimmons, Asian pears are their top selling fruit trees (followed by apples, peaches and cherries.)  They do require spraying, however, and regular pruning to keep them low enough to reach without a ladder.

Where to buy fruit trees

• Behnkes in Beltsville, MD
• Edible Landscaping near Charlottesville, VA
• Homestead Farm in Montgomery County, MD
• Boyer Nurseries near Getttysburg, PA
• PetersonPawpaws in Harpers Ferry, WV

Posted by Susan Harris.  For their help writing this article, thanks to Kathy Jentz, Cindy Brown, Kristi Janzen at Edible Chesapeake Magazine, Edible Landscaping Co, Casey Trees, Behnkes Nursery, and Scott Aker.

Thanks to Edible Landscaping for the use of these photos.

Shrubs and Small Trees for Washington Gardens

If there was any doubt as to whether Washington Gardener Magazine editor Kathy Jentz knows her trees and shrubs, it didn't last long.  She recommended a great assortment, and took every question without a pause.  What's a live audience after answering call-in questions on the radio, right?

First she showed us the magazine's "Top 10 Small Trees and Large Shrubs for your Yard", and here they are:

• Japanese maple (Acer palmatum) can take a lot of shade, and comes in a wide range of sizes.
• *Fringe tree (Chionanthus virginicus) is loved for its weeping habit and honeysuckle smell.  Its maximum height is a manageable 20 feet.  Requires full sun.
• *'Forest Pansy' redbud (Cercis canadensis") - the species grows to 40 feet but many smaller varieties are available.
• *Mountain laurel (Kalmia latifolia) will still flower even in deep shade.  Kathy recommended a visit to the mountain laurel collection near Fern Valley at the National Arboretum.  They're very slow growers, so you might want to buy a larger one.
• *Witch hazel (Hamamelis virginiana) smells spicy smell and blooms in fall.  (Asians witch hazels bloom in spring).
• Crape myrtle (Lagerstoemia indica) comes in a wide variety of sizes and is a top choice for in brutally sunny spots for their drought tolerance.  They can also handle pollution and salt.
• Korean dogwood (Cornus kousa) 'Wolf Eyes' was bred locally for disease resistance, is compact and ideal for part-shade.
• Harry Lauder's Walking Stick (Corylus avellana 'Contorta') is one you either love or hate.
• *Sweetbay Magnolia (Magnolia virginiana) is an evergreen that reaches only 20 feet in height - great size for city gardens.
• Oregon Grapeholly (Mahonia aquifolium) is another evergreen and native to the Pacific Northwest.  It likes any exposure from full sun to full shade - a real do-er!

* Denotes plants native to this region.

FOR FRUIT

• Figs are the local favorite and 'brown Turkey' does particularly well.  They require at least 4 h ours of sun.
• Blueberries do not like clay, so remove it or grow them in containers.  They're the number one choice of birds, so use netting if you want to actually eat them.
• Elderberry is a 3-footer that's become an alternative to nandina for some gardeners, and can be made into wine.
• Gooseberries? Put them in the vegetable garden.
• Currents are edible with sweeting.
• Juneberry or shadbush is grown for wildlife.

And Kathy recommends Edible Landscasping in Virginia.

There were more great trees and shrubs that flower and others that are grown for their foliage, but I'm running out of time.  I won't stop before thanking Kathy for this terrific talk, though - and for her many contributions to the urban gardening community of Washington, D.C. and environs.

Posted by Susan Harris.  Fringe tree photo courtesy of the Missouri Botanical Garden.

The Truth about Tree Boxes

By Ed Bruske

Now that tree planting time has arrived, I just finished two Citizen Forester classes at Casey Trees and came away with this startling revelation: Our city’s tree boxes are all wrong.

We pass tree boxes everyday, everywhere. They are those rectangular spaces between the curb and the sidewalk where typically a tree has been planted and typically some neighbor has boxed in the box with 4 x 4s or 2 x 6s, poured in more soil and tried to grow a bumper crop of pansies or irises or even sunflowers. Sometimes the barriers are more elaborate: wrought iron, say, or decorative metal posts with black chains strung in between. And sometimes the plantings include exotic grasses or ivies or, in many cases, just a tall bunch of weeds.

Truth is all of that stuff is bad for the trees and bad for the city. I’ll explain why in a moment. Suffice to say, the best thing we could do with those tree boxes is simply apply a layer of quality mulch to hold in moisture and inhibit weeds. Then water the tree on a regular basis and leave it alone.

You’ve all wondered, I’m sure, who keeps planting all these trees and why many of them seem to wither and die. Well, as we learned in Citizen Forester class, that strip between the curb and sidewalk that exists just about everywhere in the city is the domain of a small agency called the D.C. Urban Forestry Administration. This agency used to be under the Department of Public Works.  But it was moved to the Transportation Department, enabling the city to use federal highway funds to plant trees.

As you know, the city has lost much of its tree canopy in recent decades. Trees are vitally important to create shade in the summer, provide habitat for wildlife and turn the greenhouse gas carbon dioxide into oxygen we can breathe. Trees also transpire moisture into the air that later becomes rain. Mature trees lining a street or avenue even have a calming affect on traffic.

Almost all of the trees planted in tree boxes are the responsibility of the Urban Forestry Administration (UFA). Except the city doesn’t plant all the trees. That is the job of one contractor hired by the UFA. 

Many of the trees don’t survive.  Sometimes, explained Urban Forester Duff McCully, that’s because the tree was planted improperly. Sometimes mulch is piled up like a volcano around the base of the tree, starving the tree of water or making a home for disease. Some trees are run over by cars or destroyed by rough-housing kids. Sometimes trees are killed by people who just hate trees. (Hard to believe, but McCully insists that not everyone is a tree lover.)

Mostly, though, newly planted trees fail to survive the critical first two years because people don't water them, and are doing all kinds of wacky “gardening” things to the tree boxes. (You thought the city was responsible for watering those young trees? Think again.)

For instance, any barrier, whether wood or metal, that is placed around the tree box prevents water from running off the sidewalk and into the box. Not only does this deprive the young tree of water it needs to survive, it means more water running into the storm drains, carrying pollution into the watershed. These days, we need all the open soil we can get so that water finds its way back into the earth rather than carrying pollutants into the Chesapeake Bay.

Often after a would-be gardener builds his box around the tree box he then piles in more soil to create a place to plant flowers or shrubs. But the extra soil starves the young tree roots of air and water and creates a perfect environment for disease to attack the tree. In addition, plantings such as most perennials, grasses and ivies create a matt of roots that further restrict the flow of air and water to the tree's roots.

The final irony: the stuff the gardener plants in the tree box often dies from neglect. How often do you run a hose out to your curb? Then after everything in the tree box is dead, the box becomes a perfect receptacle for beer bottles and other garbage.

If planting anything at all in a tree box, the best choice is some small annuals around the edge of the box. Otherwise, the ideal approach for a young tree is to cover the area with a 1-inch layer of mulch, such as cured hardwood chips or bark. Don’t mound the mulch in the middle. Mound it around the edges to create a saucer shape so that water runs from the outside of the box toward the tree.

Water the tree regularly, especially during hot weather when trees are transpiring like mad. 

Casey Trees is working on a more perfect tree box design. D.C. Urban Gardeners will be doing what it can to get this message out to the public and help save our young trees. Do your part by not trying to create a garden in your tree box. And give your tree the water it needs .

To be continued...

By Ed Bruske

Now that tree planting time has arrived, I just finished two Citizen Forester classes at Casey Trees and came away with this startling revelation: Our city’s tree boxes are all wrong.

We pass tree boxes everyday, everywhere. They are those rectangular spaces between the curb and the sidewalk where typically a tree has been planted and typically some neighbor has boxed in the box with 4 x 4s or 2 x 6s, poured in more soil and tried to grow a bumper crop of pansies or irises or even sunflowers. Sometimes the barriers are more elaborate: wrought iron, say, or decorative metal posts with black chains strung in between. And sometimes the plantings include exotic grasses or ivies or, in many cases, just a tall bunch of weeds.

Truth is all of that stuff is bad for the trees and bad for the city. I’ll explain why in a moment. Suffice to say, the best thing we could do with those tree boxes is simply apply a layer of quality mulch to hold in moisture and inhibit weeds. Then water the tree on a regular basis and leave it alone.

You’ve all wondered, I’m sure, who keeps planting all these trees and why many of them seem to wither and die. Well, as we learned in Citizen Forester class, that strip between the curb and sidewalk that exists just about everywhere in the city is the domain of a small agency called the D.C. Urban Forestry Administration. This agency used to be under the Department of Public Works.  But it was moved to the Transportation Department, enabling the city to use federal highway funds to plant trees.

As you know, the city has lost much of its tree canopy in recent decades. Trees are vitally important to create shade in the summer, provide habitat for wildlife and turn the greenhouse gas carbon dioxide into oxygen we can breathe. Trees also transpire moisture into the air that later becomes rain. Mature trees lining a street or avenue even have a calming affect on traffic.

Almost all of the trees planted in tree boxes are the responsibility of the Urban Forestry Administration (UFA). Except the city doesn’t plant all the trees. That is the job of one contractor hired by the UFA. 

Many of the trees don’t survive.  Sometimes, explained Urban Forester Duff McCully, that’s because the tree was planted improperly. Sometimes mulch is piled up like a volcano around the base of the tree, starving the tree of water or making a home for disease. Some trees are run over by cars or destroyed by rough-housing kids. Sometimes trees are killed by people who just hate trees. (Hard to believe, but McCully insists that not everyone is a tree lover.)

Mostly, though, newly planted trees fail to survive the critical first two years because people don't water them, and are doing all kinds of wacky “gardening” things to the tree boxes. (You thought the city was responsible for watering those young trees? Think again.)

For instance, any barrier, whether wood or metal, that is placed around the tree box prevents water from running off the sidewalk and into the box. Not only does this deprive the young tree of water it needs to survive, it means more water running into the storm drains, carrying pollution into the watershed. These days, we need all the open soil we can get so that water finds its way back into the earth rather than carrying pollutants into the Chesapeake Bay.

Often after a would-be gardener builds his box around the tree box he then piles in more soil to create a place to plant flowers or shrubs. But the extra soil starves the young tree roots of air and water and creates a perfect environment for disease to attack the tree. In addition, plantings such as most perennials, grasses and ivies create a matt of roots that further restrict the flow of air and water to the tree's roots.

The final irony: the stuff the gardener plants in the tree box often dies from neglect. How often do you run a hose out to your curb? Then after everything in the tree box is dead, the box becomes a perfect receptacle for beer bottles and other garbage.

If planting anything at all in a tree box, the best choice is some small annuals around the edge of the box. Otherwise, the ideal approach for a young tree is to cover the area with a 1-inch layer of mulch, such as cured hardwood chips or bark. Don’t mound the mulch in the middle. Mound it around the edges to create a saucer shape so that water runs from the outside of the box toward the tree.

Water the tree regularly, especially during hot weather when trees are transpiring like mad. 

Casey Trees is working on a more perfect tree box design. D.C. Urban Gardeners will be doing what it can to get this message out to the public and help save our young trees. Do your part by not trying to create a garden in your tree box. And give your tree the water it needs .

To be continued...