Sap Season

Get your taps in. It’s syrup weather. Maple syrup. At least here in New York’s Hudson Valley, the sunny days in the 40s with nights in the 20s that are predicted should get the sap flowing.

  I say “should” because I haven’t yet checked sap buckets that I hung out on the trees a few weeks ago when winter temperatures suddenly turned warm; it was sap weather back then. That day was hopeful: I drilled holes an inch and a half deep, lightly hammered in the spiles, hung buckets, and attached covers over the buckets. Frigid days and nights that descended soon after that kept sap flow in abeyance.

  My “sugar bush” amounts to only three sugar maple trees. I used to have four, but a large tree that was a truly magnificent representative of its species began an irreversible path to its death. My older sugar mapel“Maple decline” is a disease complex brought on by some combination of drought, soil compaction, road salt, root damage, and air pollution. Upper branches are usually the first to go, and once decline begins, secondary fungi and insects speed the process along.

  I’m not sure about my tree, though, because its lower branches were the first to go. Also, the tree grows along the back edge of my property, where it’s been shielded from those usual causes for decline.

  One more contributor to decline is overtapping. I plead not guilty. My fading tree was larger than the 8 or10 inch minimum diameter for tapping, and I only tapped it once, when the tree, it turned out, was already going downhill. The lack of sap flow was what prompted me to see all this. And then I noticed many rows of sapsucker holes in the bark.

Long story short: The tree became firewood.
Maple syrup buckets
My three other, healthy maples might yield me only a quart of finished syrup. The reasons? One quart is enough for me, so I’m tapping only one of them. Also, they’re relatively young. I planted those three trees about 25 years ago, and they’re now only about 8 inches in diameter.

I highly recommend planting trees, for their beauty, for what food they might offer, and for the mere satisfaction of watching the plants grow. Especially if they are small when planted. Small trees also establish quickly to require less aftercare, often soon outgrowing their initially larger compatriots. Those three maple trees? From one perspective, it seems like a long time ago that I dug holes and set the saplings in the ground; from another perspective, it seems like I planted them, walked away, then turned right around to find that these young ‘uns have grown into bona fide trees!

Birch Sap

I may end up with more sap than planned, but not maple sap. Along with the three sugar maples I planted way back when, I also planted three river birches (Betula nigra). They grow, appropriate to their name, in a wet area just out of a swale through which water runs in spring, each a clump of a half dozen or so sturdy trunks reaching skyward to about 35 feet.

Maple might be the heaviest sap producing tree, but it’s not the only kid on the block. Many people tap their black walnut trees. Call me provincial, but black walnut syrup, much as I love the nuts themselves, has no appeal me even though I’ve never tasted it.

Birch syrup though . . . mmm. Never tasted that one either, but it sounds good. Three birch taps should offer an ample amount for tasting.River birches

What a Funny Name

  I don’t need to see the small, pebbly-skinned, orange orbs on grocers’ shelves to know that it’s kumquat season. My own Meiwa kumquat is looking very pretty, with a good crop of fruit staring out from their backdrop of glossy, forest-green leaves. I’ve trained the plant as a “standard,” that is, as a miniature tree with a crown of branches perched atop a four foot trunk.
Kumquat houseplant
 The present crop is my best ever, and traces its success back to last spring. In previous years, I was too timid with pruning. And pruning is necessary, every year. Pruning keeps the plant from growing disproportionately large for its pot -– or my house — and coaxes growth of new, fruiting wood.

The roots also get pruned each year to make space for new potting soil for root growth and nutrients. I laid down the plant and pot to easily slide out the root ball. After slicing an inch or two of roots and potting soil from all around the outside of the root ball, back into the pot the plant went, with new potting soil packed in the space between the shaven root ball and the inside edge of the pot. The seemingly brutal treatment took place last year just as the garden awoke in yellow blossoms from daffodils.
Repotting kumquat
As soon as weather warmed, new sprouts began to grow. By midsummer, the plant was fragrant with blossoms. By late summer, little, green fruits were forming which, with careful watering, survived the environment change as the plant moved indoors in October. The plant stood at attention in a sunny window in the cool bedroom for weeks, and a couple of months ago, the fruits started turning orange. They are now ripe and delicious!

Down in Dixie

Green, Green, Green, and Flowers!

After delivering a couple of lectures about gardening in North Carolina, I set off on a very short, whirlwind tour of the southeast, specifically North Carolina and Georgia, and ending with a stay in Charleston. How different from my spot here in New York’s Hudson Valley!

For all Charleston’s uniqueness, three characteristics jumped out. It being early March and my coming an achromatic landscape of snow, sleeping plant life, and cold, I was immediately struck by the abundance of greenery. Not the tired greenery of many evergreens here in the north, but vibrant, awake greenery in a variety of shapes, textures, and sizes.

Camellia blossoming in Charleston

Camellia blossoming in Charleston

Included in all that Charlestonian greenery were fronds of palm trees — saw palmetto and sabal palmetto — fanning out above jagged trunks. Those palms were a reminder that I was now in a subtropical rather than temperate climate. Not that the weather helped make the point; some days were in the high 40s and one night temperatures were predicted to dip near freezing.

March notwithstanding, Charleston had no dearth of flowers. Camellia blossoms stared out from a backdrop of their verdant foliage. Camellia is one of my favorite plants. I tried to grow one of the hardier new varieties of camellia a few years ago, offering it some cold protection by planting it near my home; it died its first winter. I wonder if southerners become blasé about these blossoms; camellias were growing everywhere, and in bloom.

The white blossoms of sweet osmanthus belied their diminutive size with the strength with which they perfumed the air. The fragrance was fruity, apricot.

Very different was another fragrance, this one wafting from clusters of trumpet-shaped blossoms dangling from the bare stems of edgworthia, also known as paperbush. That’s another plant that won’t grow this far north but no matter. I wavered between enjoying and not enjoying its resinous aroma.

If only gardenias — another plant growing outdoors in the southeast but not hardy here in the North— had been in bloom, the olfactory part of my trip would have been complete. All I could do was marvel at what it would be like if I could have a dooryard shrub of gardenia. I might be on the verge of passing out as I hyperventilated through the bloom season.

Oranges? No. ‘Quats? Yes

Two interesting fruits turned up here and there.

One was loquat, an odd relative of apple and pear. The leaves are large, dark green, and evergreen with a matte finish, all of which makes an appearance that is subtropical, which the plant is. 

Most odd is loquat’s bearing habit. It flowers in autumn and ripens its fruit in spring or early summer. I once bought one at a fruit stand in Paris. Its flavor was unimpressive, but that’s true of many commercially marketed fruits. Loquats generally receive high praise for flavor. If I ever get to taste a good one, I might grow the plant in the loquat-perfect environment of my greenhouse.

The other fruit was citrus, two fruits, actually, and also “-quats” but not at all related to kumquat. They were kumquat and citrangequate. It just didn’t seem like citrus could be hardy that far north (except for the super-cold-hardy but hardly edible trifoliate orange, which I have growing outdoors).Kumquats in Charleston But winter low temperatures in Charleston rarely dip even to freezing but kumquat trees are hardy into the ‘teens. A few citrangequats — trigeneric hybids of kumquat, trifoliate orange, and sweet orange — that I stole from a tree proved to be tasty with sweet, edible rind enclosing a pleasingly tart interior.

Southern Faves

Three of my favorite plants that I cannot grow were present in abundance. I already mentioned camellia. Another is southern magnolia, a stately tree that differs from northern magnolia in having very large, leathery, evergreen leaves that look somewhat like the rubber trees that are common houseplants.

Southern magnolia decked with Spanish moss

Southern magnolia decked with Spanish moss

It was too early for the large, white, fragrant blossoms to appear but I would grow the tree for the leaves alone, if I could. It’s almost hardy here; I’ve seen trees in northern New Jersey.

Another favorite is a deciduous plant also almost cold-hardy here: crape myrtle. The plants are decked with bright flowers in various shades of red all summer, but are bare of leaves or flowers in winter, even in South Carolina. No matter, crape myrtle has a mottled, shedding bark that puts on a good show when its flowers are offstage.Crape myrtle bark

And A Dark Cloud

A dark cloud that hangs over Charleston is its role in the slave trade. About 40% of all slaves entering America entered through Charleston. And it’s not just a statistic like this or a visit to the Slave Museum, site of one of Charleston’s many slave auctions, that recalls the horrors of human bondage. I couldn’t help, when visiting the plantations in and near Charleston, constantly reminding myself that they were only possible with the labor of enslaved humans. Reminders are everywhere; even the bricks of the buildings right in town were hand made by slaves.

Many of the slaves auctioned off in Charleston were separated from their families and transported to other sites throughout the colonies, making all the colonies and then states culpable. 



Figs (Cuttings) Galore!!

Cold weather and short days have put a not totally unwelcome lull in the gardening year. Nonetheless, I wander into the greenhouse occasionally just to drink in the sight and smell of lush greenery suffused in warmth and humidity, and to pull some weeds. The figs in there could use some pruning; they are dormant and leafless and need all stems cut back to 3 to 4 feet in height.Pruned fig tree

Gardening lull or not, I can’t just toss those cut stems away, putting them to waste. Each stem can make a whole new tree, and fairly easily. So I set up a little propagator for rooting some of these “hardwood cuttings.”

Being leafless, the cuttings lose little water so have no need for the high humidity demanded by softwood cuttings, which are cuttings taken while plants are actively growing and leafy. Any cutting, hardwood or softwood, does need its bottom portion, where roots will form, cozied in moisture and air. Some people just plop stems into a glass of water. That works for easy-to-root plants, like fig, as long as the water is occasionally changed so bacteria don’t build up and the roots get some oxygen from the freshly drawn water. Roots formed in water are morphologically different from those in soil, so the eventual and inevitable transfer to soil must be done with care, with attention to root breakage, aeration, and moisture.

My cuttings will root directly in soil, or a “soil” of some sort, actually a soil-less soil similar in makeup to most commercial potting mixes. This soil is nothing more than a mix of equal parts perlite, a “popped” volcanic rock, and peat moss. The perlite is for aeration; the peat moss is to hold moisture. (Coir, a byproduct of the coconut industry, or leaf mold could be substituted for the peat moss.)

Now here’s the cool part: After filling a large flowerpot with the rooting mix, I scooped out the center and put into the hole a smaller flowerpot. That smaller flowerpot has to be terra cotta and unglazed. It also needs it’s drainage hole plugged; some moldable wax, saved from when my daughter had braces, worked well. (I knew I had saved that wax all these years for something!) Rapping the large pot and pressing lightly on the soil ensured good contact and a continuous capillary connection between the water in the inner pot, the porous wall of the pot, and the surrounding soil.Fig cuttings in home made propagator

I slid the cuttings into the circle of soil with only one or two upper buds showing. Until leaves appear, and there’s no rush, the only attention the pot needs is to keep the inner reservoir of soil filled with water. Once leaves appear, the cuttings need light.

Sometime I’ll have to figure out what to do with all my new fig plants.

A Dream Breaks The Lull

New plants in the wings could have been the spark for a horticultural dream the night following setting up the propagator. In this dream, I lived in a large, modernistic house, the most significant features of which were its 3 stories and large, south-facing windows. I evidently wasn’t all that familiar with the house because I wandered around in amazement.

Most amazing were the plants sitting in the windows: potted fruit plants of all sorts, everywhere I turned. In one window was a potted pawpaw tree, in another a peach, then a guava, and still other fruits in other windows. Turning to go down the stairway from the uppermost floor, I came upon small pots of strawberries. (The floors themselves were broad expanses of polished wood and furniture was sparse or absent.)

Strawberry guava

Strawberry guava

Most amazing was the shadow of a lush plant hanging in front of a shaded window. Coming closer, I saw that the plant in the hanging basket was a grape vine, a compact-growing one and that was loaded with tight bunches of delicious, ripe grapes.

Much of the dream is not far-fetched. True, I don’t live in a large, modernistic house of 3 stories. But some of my windows are, in fact, home to such edibles as bay laurel and rosemary. I even have some fruiting plants, tropical and subtropical ones such as Meiwa kumquat and Golden Nugget tangerine rather than pawpaw, grape, and other temperate-zone plants that need to experience winter.Meiwa kumquat plant

A strawberry guava I once grew gave me good harvest in late autumn. Kumquats ripen in early winter. I look forward to my first tangerine and Meyer lemon harvest. Fruiting takes energy, so all these fruit plants sit near sunny windows. Indoor fruiting by a shaded window only works in dreamland.

Awake, Finally

In that same dream, I was in school. (I spent an inordinate number of years in school.) In the dream, I couldn’t keep track of my school assignments, even what classes I was taking or where. I was too preoccupied with caring for all those plants in all those windows at home.

It was good to wake up to a gardening lull.


More Citrus in the Making

You wouldn’t think that a couple of small, green sprouts could elicit so much excitement. Especially this time of year, with vigorous, green shoots sprouting up all over the place. But they did, in me. Not that anyone else would notice the two sprouts.
    The sprouts were from grafts I made a couple of months ago. Over the years I’ve done hundreds of successful grafts; these two were special.
    The first was citrus, special because the trees are subtropical and evergreen. The many apples, pears, and plums that I’ve grafted over the years are deciduous. I graft them when they are leafless and just about ready to start growing. Because the grafts are leafless, the wood, as long as the graft union is sealed, won’t dry out.
    Not so for citrus, more specifically for the stems I clipped off my potted Golden Nugget tangerine tree. What was needed, then was a rootstock on which to graft that stem. The result would be a Golden Nugget plant above the graft (which stays right where it is no matter how much the plant grows). Clipping all the leaves from the stem forestalled moisture loss.
    My home is also home to kumquat, another citrus that lives in a pot here, outdoors in summer and in a sunny window in winter. A couple of February’s ago, I glanced down at the kumquat seeds I had just spit out from fruits I harvested and ate. Not being able to squander their potential, I planted them in pots. A decade might have gone by before they were old enough to bear fruit but, after two years, the pencil-thick stems were large enough for grafting.

Citrus graft, a success

Citrus graft, a success

   With kumquat rootstocks poised for the operation and Golden Nugget scions (the stem to be grafted atop the rootstock) stripped of leaves and also ready, the procedure was the same as for apple trees and other deciduous plants: matching, sloping cuts on rootstock and scion held in place by a wrapping with a rubber strip; covering the wound to prevent moisture loss. My usual choice of covering is Tree-Kote, which gets painted on, or Parafilm, a stretchy film that adheres to itself.
    The citrus scion was fleshy enough to also lose moisture right through the bark. To prevent this, I wrapped the whole scion in the Parafilm. A blackened scion had followed previous attempts at grafting citrus without wrapping the stem.
    A week or so ago, it was time to unwrap the Parafilm from around the stem. If the grafted parts were going to knit together, they should have done so by then. Lo and behold, a small, green sprout soon pushed out from the top bud of the scion.

 Nutty Grafting

    Not all deciduous trees are as easy to graft as apple and pear. Nut trees in the Juglandaceae family, which includes black walnuts, English walnuts, butternuts, pecans, and hickories, are notoriously difficult. Part of the reason is because cutting a stem in spring, which is, of course, unavoidable when grafting, makes these trees bleed, messing up the works.
    With a slew of failures at grafting this family under my belt, I needed to try again. The candidate this year was a nut tree called buartnut, and hybrid tree with a hybrid name, the latter a non-euphonious combination of the words “heartnut” and “butternut.” Heartnut is a Japanese species of walnut, notable mostly for how easily it cracks to yield two heart-shaped nutmeats. Butternut is a richly flavored nut borne on a native tree that is becoming increasingly rare because of a blight disease.
    Buartnuts allegedly need cross-pollination to bear nuts. My tree, large and spreading though only about 15 years old, lacked a mate. The mate needn’t be a whole other tree; a branch from another tree, grafted on my tree, would suffice and avoid the need to plant a whole new tree or wait the years it would take to flower. Grafted branches bear much more quickly than new trees.
    Fortunately, I knew of another buartnut tree that could provide pollination. Last winter, I clipped off a few of its stems, packed them in a plastic bag, wrapped the bag in a wet towel, and then packed that whole mess into another plastic bag and then into the refrigerator. There, they remained hydrated and dormant until needed.

Heartnut graft, one sprout

Heartnut graft, one sprout

    The key, I’ve been told, to grafting Juglandaceae, is to wait in spring until a spate of 80 degree plus weather is predicted. Conditions seemed right on a day last May. Because of past failures, I attempted numerous grafts, three different kinds: the bark graft, the banana graft, and the whip graft. To promote bleeding off-site rather than at the grafts, I slit stems below the grafts. I covered one of the bark grafts with a plastic bag and then, for shade so the stems wouldn’t cook, a paper bag.
    Almost all the grafts failed. Except one. Just one stem of just one of the bark grafts (each of these bark grafts carries 4 or 5 stems) sprouted. How exciting!

Temple Disruption

    Exciting goings-on in the blueberry patch also. Birds are flitting about every morning, enjoying a few berries despite our repeated efforts to secure any openings in the walk-in “Blueberry Temple.” I threaded some string to more tightly join the top and side netting. As previously, I think this will solve the problem.
    Then again, this may be a Darwinian experiment. Birds never used to work their way into the Temple. Openings in the top netting are 1” across; I fear the net is breeding for smaller models of cedar waxwings and catbirds. Or perhaps smarter ones better at finagling their way to the blueberries


Paradise Under Glass, and I Take a Bit of it Home

Wandering in and out of the narrow alleys, I could barely squeeze past other, potential buyers. On my way back from a lecture and book selling, a wad of money was burning a hole in my pocket. I muttered to a young couple who glanced up to let me pass, “I feel like a drug addict.” A fleeting, sympathetic smile, and they, like others, were again intent on the offerings, hardly aware, like us other “addicts,” of other humanity.Inside Logee's Greenhouses.

I was lucky, able to leave Logee’s Greenhouses in Danielson, CT only $75 poorer. But richer in plants. Perched on the tray that I carried to my car were small plants of fragrant wax plant (Hoya odorata), Nordmann Seedless Nagami kumquat, and Golden Nugget mandarin (tangerine), all three promising to offer, for years to come, sweet fragrance, beauty, and good eating in the case of the mandarin and kumquat. By not allowing myself to dawdle, I was able to keep my trembling hand from grabbing at a Black Mission fig plant, a Dwarf Cavendish banana plant (“only 3 feet high!”), or a Hoya lauterbachii, with fragrant blooms the size of teacups. 

Most of Logee’s plants are small and not cheap, understandable considering the wide array of plants they stock. Aside from my kumquat and mandarin, I could have chosen from among a dozen other citrus varieties, including some interesting oddities like Buddah’s Hand Citron, whose fruit does, in fact, look like the draped fingers on a hand. Instead of the fragrant wax plant, I could have driven home with any one of 15 other species or varieties of wax plant. Not that Logee’s is limited only to fragrant or fruiting plants. They stock almost a 100 different kinds of begonias, among other houseplants.

Part of the jasmine collection at Logee's

Part of the jasmine collection at Logee’s

Entering the greenhouses is an experience very unlike that of entering most commercial greenhouses, the latter with their soaring roofs of crystal-clear glass, their buoyant atmosphere, and scoured concrete floors. Logee’s is Paradise for plant lovers, with a mix of concrete and dirt paths so narrow that leaves and tendrils grab at you from either side. Fortunately, plants are more organized at Logee’s than in Paradise: collections of such plants as citrus, passionflower, orchids, and angel’s trumpets are each grouped together. Perhaps the star of the show is the Ponderosa lemon tree, shipped by train then horse and buggy to the greenhouse in 1900 and still bearing crops of grapefruit sized lemons (also called American Wonder lemon and thought to be a hybrid of lemon and citron, originating as a seedling the 1880s). Over the years, it’s given rise to numerous offspring, one of which you can purchase, growing in a 2.5” pot, for $11.95.

Citrus: New Plants from Old

New plants of Ponderosa lemon and other citrus varieties can be propagated one of three ways.

Lemons and limes tend to root easily from cuttings, which are leafy branches with their bases plunged into a moist rooting medium such as a 1:1 mix of perlite and peat moss. Because citrus are evergreen, air around the cuttings has to be kept humid enough so the still-rootless stems don’t dry out. A clear plastic or glass tent does the trick. The leaves need to photosynthesize so they have energy to make roots, so some light is needed. Not too much, though, or the cuttings cook in their tent.

Special rooting hormones, which are synthetic analogues of natural plant hormones, help cuttings to root. Synthetic hormones are used because they decompose more slowly than natural hormones (and in different concentrations, are used as herbicides, such as 2,4-D). Another possibility is to soak the cuttings in water in which have steeped stems of willow, a plant that roots very easily so presumably has some root-stimulating goodies to share. I avoid the hassle of natural or synthetic hormones in rooting cuttings and, instead, pay careful attention to which stems I select for rooting, the rooting medium, and light.

Some citrus varieties can be propagated by seed. Usually a seed-propagated fruit gives rise to a baby different from the mother plant, reflecting the jumbling around of chromosomes as pollen and egg cells united. However, a few plants, and many citrus, exhibit apomyxis, where the seeds, although they look like normal seeds, are formed from cells of only the mother plant.

My new plant acquisitions: hoya and 2 citrus.

My new plant acquisitions: hoya and 2 citrus.

All the seedlings, then, are clones of each other and their mother. Well, not all, because in a given fruit, some seeds may be apomyctic and others may be the product of pollination. The apomyctic seedlings show their presence by their greater vigor and more upright stature.

Downsides to propagation by seedlings, apomyctic or otherwise, are that plants must go through a juvenile phases of some years before they are old enough to flower and fruit. Also, most citrus tend to be very thorny in their youth.

Kumquats Roots for Tangerine Tops

One way I justified my purchases at Logee’s was with my plan to use my new citrus plants to make more plants — by grafting, the third way of propagating citrus. All that’s needed is any citrus rootstock; they all are graft compatible. Not being able to throw away seeds, I have a few kumquat rootstocks started from seeds I spit out from my Meiwa kumquat fruits as I ate them a couple of years ago.

I’ll graft in spring, taking stems from the Golden Nugget mandarin to make a whip graft, a particularly easy kind of graft that gives quick results. Basically, a smooth, sloping cut on the kumquat rootstock will be matched against a similarly smooth, sloping cut on the “scion,” which is the stem I cut from the mandarin stem, with both bound together with a wrap of tape or cut rubber band. After removing leaves from the scion, grafting compound (Tree-Kote) or Parafilm seals the graft and scion against dessication before the scion and rootstock knit together, and the scion piece begins to grow.

The final step will be deciding what to do with my growing citrus orchard in pots. Plants for my annual sale, perhaps? The largest citrus orchard (potted) in the Hudson Valley?

Citrus, Flying Dragon

Citrus in New York?

Winters have been warmer here for the past few years and, so far at least, this winter is playing out to be the warmest ever. But even the “global warming” cloud has its silver lining. Snow is great fun and cold is invigorating but one of my regrets in living in a cold winter region has been not being able to harvest fresh citrus fruits from outdoor trees. If things keep progressing in their present direction, as predicted, that situation may change.
The coldest temperature so far this winter has been down around 9° F, and three of my citrus plants still look fine. In the ground, outdoors! Technically, they are a citrus relative, Poncirus trifoliata, also known as trifoliate orange. The leaves resemble citrus leaves, the white flowers resemble and have the fragrance of citrus flowers, and the fruits, orange and an inch-and-a-half across, resemble citrus fruits inside and out. Too bad poncirus is barely edible, although it can be squeezed for juice that is diluted and sweetened to make an -ade.
Flying Dragon poncirus
Even if poncirus was not edible, it would be worth growing for its beauty, especially the Flying Dragon variety with its contorted, green (and thorny) stems and leaves.
My three poncirus plants started out as seeds plucked from a fruit on a plant growing against a brick wall in northern New Jersey. The seeds sprout and grow easily. After growing one year in pots, into the ground they went. The first couple of years, winter lows of -10° and -19° killed them back to the snow line. They’re allegedly cold-hardy below zero degrees F., but that hardiness comes with age. Also, the pattern of cold development and its duration affects cold-hardiness. This year, so far, the plants look fine from top to bottom.
Poncirus is close enough to citrus botanically that its been hybridized with citrus to make more edible, albeit less cold-hardy, hybrids. Like the citrange, from the mating with sweet orange, hardy to 5 to 10°F. A few varieties of citrange have been developed, all billed as “approaching edibility” but, like poncirus, making a good -ade.
Not to give up on true citrus — yet. Probably the hardiest is yuzu, a hybrid of a sour mandarin and the barely edible Ichang papeda (C. ichangensis). Ichang papeda is the hardiest evergreen citrus. (Poncirus sheds its leaves in winter.) So yuzu is a true citrus and it is quite cold-hardy, down to about 10°F. And it is eaten. The great plant explorer, Frank N. Meyer described it, in 1914, “rind full of oil glands, smelling like a fine lemon; segments separating easily; fairly juicy and of an agreeable sharp sour taste.”

Mandarins (tangerines, C. reticulata) are also among the hardiest of citrus, and they taste very good straight up. The deep orange fruits of the variety Changsha are sweet and juicy, and I actually have a potted plant from which I’ve been trying to coax fruit for more than 5 years — or so I thought.
Today I checked the original bag in which I received cuttings of the alleged Changsha. Turns out the name scrawled on the bag is Changshou, not Changsha. Bummer, I was looking forward to Changsha. Changshou is another hardy citrus-type fruit, actually a kumquat, from the closely related genus Fortunella. Kumquats are cold-hardy to between 10 and 20°F., and are a fruit I’ve grown — indoors in winter, outdoors in summer — for many years. 

Meiwa kumquat
Kumquats, like poncirus, hybridize readily with citrus species. Hmmm, why not combine the hardy kumquat with the hardy mandarin? It’s been done, the result of the mating being the Nippon orangequat, hardy to 10°F. and with a mild flavor, if left to hang on the plant long enough, and, like a kumquat, having an edible skin.
Except for poncirus, I’m not really hoping to harvest any citrus-type fruits from outdoor plants anytime soon, perhaps ever. Surviving the depths of winter cold is one thing. The plant also has to be able to ripen its fruit within the growing season. My Meiwa kumquats, for instance, ripen in February, and I expect even a few nights in the 20s would turn the fruit to mush.
For now, then, I continue growing the more edible citrus-type fruits in pots that winter indoors. Still, poncirus, that citrus look-alike will look cool out in the landscape.