Pollarding Is Extreme Tree Pruning

50128thumb
Pollarded knuckles look like science fiction.

Most arborists insist that pollarding is horticulturally incorrect. However, most of us who pollard trees in our home gardens are not arborists. Pollarding is technically detrimentally disfiguring to trees. However, some trees that are naturally short lived can live much longer if pollarded properly. That is the trick; doing it properly. Pollarding is certainly a distinctive pruning style that is not for everyone, but can be both practical and sustainable in certain situations.

Pollarding is an extreme pruning technique that involves the removal of all or almost all of the stems that grew since the last time the technique was done. The new growth gets cut back cleanly to distended ‘knuckles’ that develop at the ends of the original stems. Traditionally, one or two strategically aimed stubs from the removed new growth are left on each knuckle to form a new knuckle a bit beyond knuckles of the previous year. Locally though, stubs are typically omitted.

New growth must get cut back cleanly so that the wounds can get compartmentalized (healed over) as efficiently as possibly. Stubs interfere with this process. If one or two stubs are left on knuckles to form new knuckles, they should be long enough to get some distance from the original stubs, but short enough to not be too awkward. Knuckles should not get cut off! Such large wounds do not compartmentalize fast enough to avoid rotting.

Pollarding can only be done in winter, both because plants are dormant, and also because the weather is not so dangerous. New growth starts to shade exposed bark before it gets scalded by intensifying sunlight and heat in summer. Once they come out of dormancy, plants would be seriously distressed by such severe pruning. Because new growth is so vigorous after pollarding, it can become sloppy if pollarded less than annually. Some plants that grow slowly or produce stout stems may get pollarded less frequently.

London plane (sycamore) and fruitless mulberry are the most commonly pollarded trees. Silver maple, silk tree and various elms, willows and poplars adapt well to pollarding as well. Locust and purple leaf plum can be pollarded, but will be deprived of bloom. Bottlebrush can bloom later in the same year after getting pollarded, and probably will not need annual pollarding anyway. Pollarded bay trees can be kept small, and will provide better herbal foliage. Certain eucalyptus can be kept juvenile if their juvenile foliage is more appealing than their adult foliage.

Horridculture – Memorials

P00129
Where are the cedars?

Memorial trees should be remembered . . . right? I mean, they are planted to remind us of . . . something, or . . . someone. They are typically trees that will be around for a long time, because that is how important memories should be. Redwoods and oaks work nicely. Most get outfitted with plaques to remind everyone what the trees are there to remind us of.

The old original Sunnyvale City Hall was landscaped with several memorial trees. The most prominent were redwoods and cedars that were mostly planted as memorials for local veterans of various wars. They accumulated over several decades and a few wars. City Hall seemed like a good place for them, where they could live for a long time without bother.

However, City Hall was demolished in the late 1970s, and replaced with a big mall. The larger redwood and cedar memorial trees were salvaged as the mall was build around them. Most survived in a courtyard within the mall until the mall was partly demolished less than a quarter of a century later.

All the cedar memorial trees died in captivity within the courtyard. One redwood that was not a memorial was added to the group where one of the cedars had been.

Prior to the demolition of the courtyard, I needed to inspect the surviving redwood to prescribe procedures for safe removal of surface pavement, and subsequent protection of exposed roots. The surviving trees were in remarkably good health. I was not very worried about them. What bothered me though, was the complete disregard for their historical significance.

The plaques associated with these memorial trees were a mess. It was as if they all had been collected from their respective trees, mixed up, and replaced randomly. Plaques from the absent cedars were assigned to some of the surviving redwoods. The oldest and grandest memorial redwood was labeled as the redwood that was added last, after the mall was built, and therefore of no historical significance. The smallest and youngest redwood that really was added after the mall was built was labeled as one of the more historically significant memorial trees.

I believe that all the trees that were there during my inspection are still quite healthy within a small park space that was built around them. I have no idea if they are outfitted with plaques. If they are, I can not help but doubt the accuracy of those plaques.

Canna

00205
Cannas are just dormant rhizomes now.

It is difficult to document the lineages of the countless modern garden varieties that have been hybridized from ten species of Canna. Straight species that are popularly grown within their native ranges are rare here. Some species are grown for their thick edible rhizomes. Many are grown for edible foliage. Some are employed to absorb toxins from contaminated riparian environments.

Garden varieties that are popular here are grown merely for their aesthetic appeal. The lushly big leaves are typically rich green, but might be bronzed, dark purplish bronze, or striped with yellow, bronze, creamy white or peachy pink. Large varieties get taller than eight feet. Compact types stay less than three feet tall. All foliage dies to the ground after frost, and grows back fast in spring.

The flashiest parts of canna flowers are actually very specialized stamens known as staminodes, which mostly obscure the very subdued petals and sepals. Red, orange, yellow, pink, salmon or very pale yellowish white bloom may be spotted or blotched. Flowers might be thin and wispy, or rather floppy and lush. Canna are popularly known as canna lilies, but are not at all related to lilies.

Bulb-Like Perennials For Summer

00205thumb
Dahlias planted now bloom in summer.

Like something of bad science fiction, they are back. The earliest of spring bulbs that were so discourteously buried in shallow graves last autumn are making their presence known. Even before the weather gets noticeably warmer, their foliage emerges above the surface of the soil. Daffodil, narcissus, crocus and snowdrop are already blooming. Hyacinth, tulip and anemone will be next.

We know them as spring bulbs, or alternatively, as hardy bulbs. However, in this climate, many bloom through late winter, so are finished by spring. Also, many are technically not really bulbs. They might be corms, rhizomes, tubers or tuberous roots. They are hardy bulbs because they want to be planted through autumn so that they can get a bit of chill through winter before their early bloom.

Some spring bulbs require a bit more of a chill than they get in the locally mild climate. They bloom very well in their first season because they are pre-chilled before they are sold. Once dormant, they get dug and chilled in refrigeration to entice them to bloom well for subsequent seasons. That happens much later in the year though. For now, long before spring, we get to enjoy their bloom.

Summer bulbs, which are not so hardy, are what gets planted about now. Their planting is delayed, not just because they do not need chill, but also because they dislike it. If their foliage develops too early, it can be damaged by late frost. Once established, summer bulbs are more resilient to minor frost damage of premature foliage. They can therefore remain in the garden for many years.

Canna, dahlia and big old fashioned white calla are the simplest of summer bulb-like perennials to plant now. Those that are already established can be divided if crowded. The smaller and more colorful callas can be a bit more finicky. Gladiolus and various lilies are spectacular, but bloom only once annually, rather than throughout summer. They are also unlikely to establish as perennials.

Bulb-like perennials that bloom only once might be planted in phases to prolong their potentially brief bloom season.

How To Train Your Dragon

P00126
Oh, the SHAME!

Dragon fruit became a fad on the West Coast of California several years ago. They were probably always around, but had previously been rare. When they inexplicably became more popular and common, they did so down south first. Their popularity migrated to the Santa Clara Valley a few years later. It probably will not go much farther though, since they are sensitive to frost.

It is not a bad fad, at least relative to most others. Dragon fruit, which is also known as pitaya, happens to be very easy to grow and propagate from cuttings. Locally, it needs protection from frost, but no more than other popular tropical plants. It recovers from minor frost damage quite efficiently. Pruning scraps can be rooted and grown as more plants for friends and neighbors.

Of course, I dislike fads. I am not impressed by the fruit, which might lack flavor here where the weather does not stay very warm for very long through summer. The coarsely textured and floppy plants get big and awkward. They are typically trained up onto posts from which their many long stems hang downward. An exemplary specimen looks like Sigmund the Sea Monster.

This is a fad that I dislike enough to try. I want to see what all the fuss is about. These are my first two cuttings. The upper cutting produces red fruit. The lower cutting that is marked with a line to show how deeply it should be stuck into rooting medium produces white fruit. I will know where to release them into the landscape by the time they develop roots and start to grow.

This is so shameful that I probably should not be writing about it. Oh well. Perhaps in a few months, I will write about how these cuttings will be progressing.

Wild Strawberry?

P00125K
Wild strawberries are worth salvaging.

Under a bank of carpet roses that I am none too keen on, this grubby ground cover competes with more aggressive weeds. To me, it looks like common mock strawberry, Potentilla indica. I never gave it much though. It seemed to me that whoever had installed cheap and common carpet roses on that bank would have employed a comparably cheap and common ground cover.

The ground cover was more prolific in open spots that were too narrow for more of the roses, and from there, seemed to have migrated under the roses as a second layer of ground cover. It would not have been installed underneath intentionally. It did not occur to me that it may have grown from seed like so many other weeds there, or migrated in from the surrounding forest.

The white flowers did catch my attention though. I was not aware of a mock strawberry that bloomed with white flowers. I really was not concerned enough about it to investigate. This part of the landscape will be getting renovated soon anyway. The roses will be relocated to where they can not extend their thorny canes into an adjacent walkway. Agapanthus will replace them.

Now that I am seeing more of these odd strawberries, I am wondering if this low ground cover that I formerly had no regard for is actually the native wild strawberry, Fragaria californica. Not only should mock strawberry bloom with yellow flowers, but it should also produce more spherical berries. Now I will need to identify it before I either dispose of it, or merely relocate it.

I prefer to not salvage exotic species that exhibit potential to naturalize from landscaped areas into surrounding forests. If this ground cover is wild strawberry, it migrated from surrounding forests into a particular casually landscaped area.

Six on Saturday: Poison Ivy

 

Poison ivy is not native here. Neither is English ivy. However, English ivy, Hedera helix, is an aggressively naturalized exotic species. Even after it had been designated as a voracious weed in the region, it was installed in some of the landscapes here many years ago. It is so common here now that we know it simply as the standard ‘ivy’. Algerian ivy was planted too, but it is not quite so aggressive.

1. English ivy grew up and over this abandoned building, and accelerated the deterioration of the old roof. It would be pointless to remove it now. The building will eventually be demolished.P00125-1

2. This building is not abandoned. No ivy was on this roof just a few days earlier. All this ivy did not grow up and over the building this aggressively since then, but fell from above. Surprise!P00125-2

3. The yellow pointer shows where the dead redwood trunk that supported all the ivy broke and dropped the whole mess onto the roof at the bottom of the picture. It is about thirty feet up!P00125-3

4. What a mess! This close up of the same broken dead redwood trunk shows another dead redwood trunk to the right, and a viable trunk with another dense ivy thicket in the background.P00125-4

5. Surprisingly, this is the worst of the damage. It was likely impaled by the rotten redwood trunk. The ivy likely stayed connected to the rest of the thicket long enough to slow the descent.P00125-5

6. Even after getting Ginsu with saws and shears, and getting bounce-house with debris, the pulpy redwood trunk and ivy was still a full load. That was a lot of weight to land on an old roof!P00125-6

This is the link for Six on Saturday, for anyone else who would like to participate:

https://thepropagatorblog.wordpress.com/2017/09/18/six-on-saturday-a-participant-guide/

Black Mondo Grass

50121
The foliage really is this dark.

The deeply colored foliage of black mondo grass, Ophiopogon planiscapus ‘Nigrescens’, is about as convincingly ‘black’ as foliage can get. It is darker than bronze New Zealand flax, purple leaf plum or bronze coral bells. Only purple beech or chocolate coleus are comparable. The foliage is dark enough to contrast very well against lightly colored planters or gray concrete, so works well in urns or mixed perennials, and bordering walkways. If it gets enough sunlight, black mondo grass makes a nice small scale ground cover under Japanese maples.

Mature plants stand only about half a foot tall, and spread slowly. The happiest plants can get nearly twice as tall. The softly cascading leaves are only about a quarter inch wide. Small spikes of tiny pink flowers that sometimes bloom in summer would contrast nicely against the dark foliage, but are rarely seen above the foliage. Black mondo grass prefers rather rich soil and somewhat regular watering. However, as they disperse roots, older plants do not seem to mind too much if they briefly get a bit dry.

Figs Are Easy To Propagate

50121thumb
Some grasses can propagate by division.

The easiest way to propagate new fig trees may seem to be violent, but it works. Basal shoots that grew last year from the roots near the trunks of ungrafted trees can simply be torn out of the ground with as many attached roots as possible. These shoots can then be planted directly wherever new trees are desired, and watered in. Larger shoots may need to be dug out, and might do better if pruned down to just a foot or two tall when planted. Smaller shoots can be potted to grow through next summer, and then get planted in the ground next winter.

Tearing the shoots off in this unpleasant manner is effective for two reasons. It gets the most roots for the shoots to help the grow into new trees. It also removes more of the burl growth that produces the shoots than simply cutting the shoots neatly. Even if copies of the original tree are not desired, the basal shoots must be removed anyway. Simply pruning them away leaves more burl growth so that more shoots grow back next summer. Ideally, well maintained trees should actually not produce basal shoots.

Fig trees are innately easy to grow from basal shoots or cuttings while dormant through winter. Basal shoots, even those that get pulled without any obvious roots, will develop roots more efficiently than stem cuttings that were never in contact with the soil. However, if no basal shoots are available, stem cutting work just fine. Furthermore, grafted trees (which are quite rare) can only be copied by cuttings from above the graft. Basal shoots from below the graft will only produce copies of the understock.

Just as unwanted basal shoots and cuttings from pruning scraps can be grown into fig trees, overgrown perennials in need of thinning can be divided to propagate more of the same. Lily of the Nile, red hot poker, daylily, mondo grass, African iris, terrestrial yuccas, some ferns and some grasses are not only easy to propagate by division through winter, but many perform better if divided every few years or so, before they get too crowded. The common giant yucca develops big trunks instead of clumping shoots, but can be propagated just as easily from big cuttings.

Horridculture – Dried Plums?

00115
Dried prunes are experiencing something of an identity crisis.

Nomenclature used to be more predictably standardized than it is now. When I write about how it works, I compare it to the names of cars. For example, ‘General Motors’ is just a family. ‘Buick’ is a genus. ‘Electra’ is a species. ‘Limited’ is a variety. Well, my Sebring was labeled as a Chyrsler but made by Mercedes Benz. Modern horticultural nomenclature is no more accurate.

With all the promiscuity going on nowadays, it is impossible to know who the parent of some of our favorite plants are. Many are interspecific hybrids. Some are intergeneric hybrids. Some are so complicated that their species names are merely omitted; and no one seems to notice! That is like driving a Mercury LS without knowing or caring if it is a Grand Marquis or a Lynx.

So, now we can grow such aberrations of traditional stone fruit as as aprium, apriplum, pluot, plumcot, nectaplum, pluerry and peacotum. The first half of the names supposedly indicate who the promiscuous maternal parent is. The second half refers to the male pollinator. Parents who contributed fewer letters to the name were supposedly already hybridized prior to breeding.

For example, an apricot pollinated by a plum creates an aprium; and an aprium pollinated by a plum creates an apriplum. The apriplum gets an extra letter from plum ancestry because it is %75 plum and %25 apricot. A plum pollinated by an apricot creates a pluot; and a plum pollinated by a pluot creates a plumcot. There are, of course, many other complicating combinations.

Sure, the resulting fruit is very good; but is it any better than what it was bred from? If everyone could have tasted the simple, traditional and exemplary stone fruits that formerly grew in the vast orchards of the Santa Clara Valley, there would be no need for all this hooey. Besides, why is there all this interest in creating new and weird fruit while eliminating some of the old?

Prunes and plums, as I explained earlier, are two distinct types of fruits. Japanese plums are the richly flavored and typically more brightly colored fruits that were more popular in home gardens than in orchards, since they are not easy to transport. European prunes are the sweeter but mildly flavored freestone fruits that grew in orchards, generally for drying and canning.

Apparently, the name of ‘prunes’ was not appealing enough . . . or was actually considered to be unappealing. Almost twenty years ago, prunes were consequently reclassified as plums. Dried prunes are now known as dried plums, as if they are dried versions of the classic ‘Santa Rosa’ plums that so many of us grow in our home gardens. Some of them just might be! Who knows?!

Plum juice could be extracted from Japanese plums, which actually make excellently rich juice, but is more likely from fresh (not dried) French or Italian prunes. However, there is still such a beverage that is known as prune juice. It is extracted from, of all things, rehydrated dried plums . . . or dried prunes. These unfortunate fruits get dehydrated, rehydrated, and then juiced!

The juice of rehydraded dehydrated plums or prunes might be the only remaining application of the word ‘prune’. At least it is useful for that; in the sense that it designates the source of the juice as rehydrated dehydrated fruit of some sort, rather than fresh fruit of some sort. Whether such fruit is a plum or what was formerly known as a prune remains something of a mystery.