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Some Plants Impress With Bark

P80805Lemon eucalyptus, ‘Marina’ madrone, cork oak and all sorts of melaleuca trees are known more for their interesting bark than for their foliage or flowers. It helps that their distinctive trunks and branch structures are ideal for displaying their unique bark. Color and texture of bark is remarkably variable, and tends to get noticed more in winter while blooms and foliage are lacking.

Bark of sycamores, birches, elms and crape myrtles that had been so handsome throughout the year is more visible now that it is not partially obscured or shaded by the deciduous foliage that is associated with it. Trunks and limbs of European white and Jacquemontii birches are strikingly white. ‘Natchez’ crape myrtle has distinctively blotched bark, (although the white flowers are pale.)

Because of their other assets, English walnuts, figs and saucer magnolias are not often grown for their bark. Nonetheless, their pale gray bark shows off their stocky bare branch structure nicely, especially in front of an evergreen backdrop of redwoods or pines. The smooth metallic gray bark of European beech is much more subdued, but is what makes big old trees so distinguished.

A few deciduous trees and shrubs get more colorful as winter weather gets cooler. Instead of white or pale gray, their bark turns brighter yellow, orange or red. Some plants, like sticks-of-fire, do not need much cool weather to develop good color. Others get more colorful in colder climates, and contrast spectacularly to a snowy landscape. Locally, they should be well exposed to chill.

As the name suggests, the coral bark Japanese maple (‘Sango Kaku’) develops pinkish orange bark. It can get ruddier in colder climates, but may get yellowish here. Unlike other Japanese maples that get pruned to display their delicate foliage and branch structure, the coral bark Japanese maple sometimes gets pruned more aggressively to promote more colorful twiggy growth.

Osier dogwood is a shrubby dogwood that lacks colorful bloom, but compensates with ruddy brown, brownish orange or pale yellow bark in winter. (Dogwood bark . . . There is a pun there somewhere.) Because it lacks colorful bloom, it can be pruned aggressively after winter. Older canes that do not color as well can be pruned to the ground as they get replaced by new canes.

Posted on by tonytomeo · 15 Comments

Prune Now For Roses Later

70524thumb+The main problems with roses locally are not related to climate, soil, insects or disease. Warm and semi-arid climates of California happen to be some of the best places in the World for roses. Sure, many roses have problems with insects such as aphid, and diseases such as powdery mildew, but primarily because such pathogens proliferate among roses that are not pruned properly.

Yes, the main problems with roses are a direct result of improper pruning. Without adequate pruning, roses become overgrown thickets that shelter the pathogens that afflict them, but also lack the vigor to be resistant to damage. Like so many other domesticated plants, they were bred for maximum production of unnaturally big flowers, at the expense of natural resistance to pathogens.

Pruning eliminates superfluous growth and improves air circulation, which interferes with the proliferation of most types of pathogens. Most pathogens overwinter in fallen foliage that should get removed in the process. Pruning also concentrates growth of the next season into fewer new stems, which stimulates vigorous growth that hopefully grows faster than the pathogens that infest it.

Roses should be pruned while dormant in winter, after defoliation, and before buds start to swell at the end of winter. Hybrid tea, floribunda and grandiflora roses should be pruned back to only about three to six canes that grew from the base during the previous year. Older canes should be removed. Remaining canes should be only about two feet tall, and cut just above a healthy bud. Any growth below the graft union (where the basal canes originate) are genetically different suckers (from the understock or rootstock) that must be removed.

As growth resumes in spring, well pruned plants will produce fewer stems and blooms that are significantly more vigorous than those of inadequately pruned plants. Overgrown and inadequately pruned plants must spread their resources thin amongst more but significantly weaker stem growth that is much more likely to be damaged by pathogens. Aggressive pruning now pays off later.

Posted on by tonytomeo · 4 Comments

Arborists Really Know Their Trees

7bd6It is no surprise that there are many different types of physicians within the medical industries. Pediatricians, surgeons, cardiologists, dermatologists, and all sorts of ‘doctors’ are all recognized for their particular medical specialty. Yet, almost all horticultural professionals are known simply as gardeners or landscapers, even though many never work directly in gardens or landscapes.

Production nurserymen grow horticultural commodities (plants). Other nurserymen maintain these commodities while they are marketed. Landscape designers develop the landscapes that many plants inhabit. Only after the involvement of various less familiar horticultural professionals, landscapers install the landscapes, and gardeners maintain them. Somehow, they get too much credit.

Arborists really deserve more credit. They are the physicians of trees, who specialize in arboriculture, which is the horticulture of trees. Much of their work is out of reach to gardeners, and is very distinct from the sort of work that gardeners should be expected to perform. Trees are the most substantial features of a landscape, so really should get the proper attention that they deserve.

The International Society of Arboriculture, or ISA, certifies professional arborists who have passed an examination of their arboricultural expertise, and continue to demonstrate proficiency with discriminating arboricultural standards. Continued involvement with ISA classes, educational seminars and workshops is required to maintain arborist certification. It demands serious dedication.

Besides assessing the health, stability and structural integrity of trees, ISA certified arborists are the most qualified to prescribe any necessary arboricultural procedures, and to direct those who perform these necessary procedures. Most local municipalities require a report from an ISA certified arborist to accompany an application for a permit to remove any protected ‘heritage’ tree.

The website of the ISA, at www.isa-arbor.com, Is an excellent resource for finding certified arborists, and the tree service businesses with which they are affiliated. Arborists can be found by name directly, or regionally by ZIP code or city. The website is also a great resource for information about proper arboriculture and trees, and can help those who are not arborists with selection of trees.

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Bare Root Season Is Now

80124thumbAutumn really is the season for planting. That is the general rule. One generalization about general rules is that they generally do not apply to all of the specifics. In other words, there are likely certain exceptions. In this case, there are some types of plants that should not be planted in autumn. The next best season for planting is probably winter, which happens to be ‘bare root season’.

Just before the last of the Christmas trees were being sold, and relinquishing their space in nurseries, bare root stock started moving in. Some bare root stock is prepackaged with its otherwise bare roots in bags of moist sawdust. Nurseries that provide large volumes are likely to heel in unpackaged bare root stock into bins of moist sand, from which it gets pulled and wrapped as sold.

As the term ‘bare root’ implies, bare root stock was dug as early as the onset of dormancy in late autumn, and deprived of the soil that it grew in. Because it is dormant, and the weather is cool and damp, it does not mind much, if it even knows at all. As it emerges from dormancy next spring, it resumes growth, and disperses roots into the new soil that it got planted into while dormant.

Bare root stock is significantly less expensive than canned (potted) stock because it lightweight and does not take up much space in the nursery. It is also more efficient, since it only stops briefly in retail nurseries, on its way from growers to its final home destinations. New plants start dispersing roots right away, instead taking time and effort to recover from earlier confinement of roots.

Deciduous fruit trees and roses are the most familiar of bare root stock. The bare root fruit trees include the stone fruits of the genus Prunus, such as apricot, cherry, plum, prune, peach, nectarine and almond, as well as pomme fruits, such as apple, pear and quince. Figs, pomegranates, persimmons, walnuts, mulberries, grapevines, currants, gooseberries, blueberries, cane berries, strawberries, rhubarb, asparagus and a miscellany of deciduous blooming but fruitless plants are also available.

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Fireplaces Are A Rare Luxury

51028thumbThere are fewer fireplaces after every significant earthquake. Removal of a damaged chimney is probably more practical than repair, particularly if the fireplace does not get much use anyway. Wood stoves sometimes get removed simply because they are in the way. Modern building codes forbid their return once they are gone, and also forbid them in new construction.

The few surviving fireplaces and wood stoves do not get used as regularly as they used to. It seems that no one is around the home long enough to tend to a fire. Orchards that provided so much affordable firewood as they were being removed for urban development are gone now. The outskirts of town, where trees and woodlots might be found, are now more than a short drive away.

Firewood can still be purchased from tree service businesses that must dispose of the wood that their work generates. Because such firewood is a byproduct of urban forestry, it is an unpredictable mix of all sorts of urban trees, and must be procured early in the year to be seasoned by autumn and winter. It is now much too late to purchase green firewood for this winter.

Almost all types of urban firewood are comparable to more traditional types. A few types deposit more residue in chimneys, so that chimneys need to be cleaned more frequently. Firewood from woodlots can be surprisingly more expensive; but it burns cleaner, and is already seasoned. Many woodlots would be pleased to deliver firewood that is ready to burn now.

Firewood is perishable, so only slightly more than enough for one year should be procured annually. Any leftovers can rot if left out in the weather too long. Firewood last longer in a shed or garage, but takes up too much space, and can be attractive to rodents.

Synthetic logs from the supermarket happen to be more efficient than real wood, and do not need to be seasoned. A single log burns longer and cleaner than a few real logs, and produces as much heat. However, they are individually very expensive, and are just not the same as real firewood.

Posted on by tonytomeo · 16 Comments

Potted Plants Are Living Things

90109thumbCut Christmas trees really are the way to go. There is no obligation to take care of them after Christmas. They do not need to planted out into a garden that will be too small for them as they grow. They do not need to be maintained in a pot, only to get disfigured or partially defoliated before next Christmas. They simple get removed from the home and composted or otherwise disposed of.

Potted living Christmas trees may seem like a good idea, but they are not as sustainable as they seem to be. Only the smaller and more compact types of conifers can be confined to big pots or planted into compact garden spaces. Rosemary shorn into small cones happens do well either in big pots or out in the garden, and if preferred, can be allowed to assume its natural bushy form.

Many other potted plants that are popularly brought into the home for Christmas decoration are easier to accommodate but take a bit of effort. Poinsettias are the most familiar of these. They can grow as houseplants for years, and might hold their colorful bracts for months. In mild climates, they can be planted in the garden, but will never look like they did originally. Most get discarded.

Hollies and azaleas are more sustainable, but are not as popular. Of these, hollies are the easiest. They can be planted in larger pots or directly into the garden later, when the worst of winter is over. Azaleas will eventually drop their flowers, and will likely look very distressed for a few months, but if watered regularly, can regenerate new foliage that is adapted to their new environments.

Christmas cactus happens to be a delightful houseplant regardless of the season. It will also drop its flowers, but will generate appealing pendulous foliage that cascades nicely from hanging pots. It can bloom annually, although timing of bloom is quite variable. It can do the same outside, if sheltered. Amaryllis also prefers to stay potted. It will replace its tall flower stalks with a few leaves that sustain the bulbs until dormancy next autumn, and can bloom again next winter if given a chance.

Posted on by tonytomeo · 4 Comments

Prune Now For Fruit Later

70726thumbModern fruit trees have been so extensively bred to produce abundant and unnaturally large fruit, that most types are unable to support the weight of the fruit that they can produce each season. Without specialized dormant (winter) pruning to limit production, the weight of excessive fruit breaks and disfigures the limbs of the trees that produce it. Fruit becomes too much of a good thing.

Pruning not only limits the weight of the fruit; but it also improves the structural integrity of the limbs that must support it, and ideally, keeps fruit more reachable. Concentrating resources produces fewer but better fruits, instead of wasting resources on excessive fruits of inferior quality. Fewer stems that grow in spring are more vigorous and resistant to disease than more stems would be.

‘Stone’ fruits (of the genus Prunus) generally get similar pruning. However, peaches and nectarines produce such heavy fruit that they get pruned more severely than apricots, plums and prunes. Cherries and almonds are so lightweight that they may not need to be pruned at all. Cherries may be pruned for height. Since almonds get shaken from their trees, height is not so important.

Stems that grew last summer should produce fruit next summer. They should therefore be pruned short enough to support the weight of the fruit that they can produce (or what stems produced in previous years). For peaches, stems may need to be pruned to only a few inches long, even if the new stems are several feet long. Upper stems that get too high can be pruned out completely.

Apples and pears benefit from the same sort of pruning, but can be cut back even more aggressively, since their new stems tend to be more productive at the base. Crowded clusters of vigorous new stems can be thinned to eliminate the largest and most dominant stems. Stunted ‘spur’ stems that do not elongate more than two inches or so each year many not need to be pruned at all.

The ‘four Ds’, which are ‘Dead, Dying, Diseased and Damaged’ stems, are the first to get pruned out, even if they happen to be in the right places. There is just too much potential for problems later. Young trees that do not need much pruning now should be pruned for structure. Dormant fruit tree pruning is so important and specialized, that it is worth studying in more thorough detail.

Posted on by tonytomeo · 8 Comments

Secret Lives Of Christmas Trees

90102thumbPeople really stress out over Christmas trees. Some do not want a cut Christmas tree because it involves killing the tree. Some do not want an artificial Christmas tree because it is . . . artificial. Some do not want a living Christmas tree because it is too expensive for a tree that is too small. There are so many myths and misconceptions about Christmas trees, yet everyone wants one.

As mentioned, artificial trees are . . . artificial. Obviously. They are not a horticultural commodity, so are not an appropriate topic for a gardening column. What can be said about them is that they are not a more environmentally responsible option to disposable cut real trees. Countless dinosaurs died to make the petroleum for the plastic that these non-biodegradable trees are made of.

Cut trees are still the most environmentally responsible option. They are not harvested from forests, but from plantations, just like any other cut foliage, cut flowers or vegetable crops. Many are grown from the branched stumps of previously harvested trees, by a process known simply enough as ‘stump culture’. It works like coppicing, and allows some stumps to produce for many years.

Potted living trees are the most misunderstood type of Christmas trees. There is nothing environmentally friendly about them. They are exotic (non-native) trees grown in synthetic media (potting soil) in vinyl pots. They get synthetic fertilizer, artificial irrigation and very unnatural pruning while growing within artificially regulated environments that are designed to promote efficient production.

Only a few of the more compact types of living Christmas trees, like Colorado blue spruce and dwarf Alberta spruce, can survive confinement in pots for more than just a few years. Austrian black pine and dwarf limber pine need a bit of trimming as they grow, but also have the potential to work for a few Christmas seasons. The common small potted Christmas trees that are already decorated are Italian stone pine and Canary Island pine, which do not survive confinement for long, and get too big for home gardens.

Posted on by tonytomeo · 8 Comments

Winter Is Bare Root Season

80124thumbWhile dormant for winter, some types of plants get dug from the soil and sent to nurseries as ‘bare root’ stock. Some get packaged with their otherwise bare roots contained in bags of damp sawdust. Most just get heeled into damp sand in the retail nurseries where they get sold. These simply get pulled from the sand when sold.

At their new home gardens, bare root plants simply get planted where they will sleep through the rest of winter. In spring, they wake up and start to grow as if nothing ever happened. How sneaky! They do not need big holes for their bare roots. Their graft unions (the ‘kinks’ at the bases of the trunks of grafted plants) must stand above grade. Roots only need to be spread out laterally.

Soil amendment should be minimal. Too much soil amendment promotes root growth around the trunk, which can inhibit root dispersion elsewhere. Too much excavation and amendment below the roots may eventually settle, so that graft unions sag below grade, and get buried. A light dose of fertilizer a bit later promotes early root growth, even while the branches are still bare.

Bare root plants are much more portable than canned (potted) plants. Several can be wrapped and sent home in a small car, or even through the mail; which is why so many bare root plants can be purchased online. (Climate zones should be considered when purchasing online.) Because they occupy less space than canned plants, many more varieties are available in nurseries.

Because they are so easy to handle and process, bare root plants cost about a third of what canned plants cost. Mail order plants from growers often cost even less than those that must be sent to retail nurseries first. Bare root plants are at least as reliable as canned stock, disperse roots more efficiently, and are less likely to be infected with disease when they arrive.

The most popular bare root plants are roses, cane berries, grapevines and fruit trees, like apricot, peach, nectarine, cherry, plum, prune, almond, apple, pear and persimmon. Flowering crabapple, flowering cherry, poplar, lilac, forsythia, wisteria, rhubarb, strawberry and asparagus are also available.

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Berries For Color In Winter

81226thumbIn milder climates of California, where many of us expect at least a few flowers to bloom right through winter, autumn foliar color and colorful winter berries are not appreciated quite as much as they are where autumn and winter arrive earlier, and are cool enough to prevent lingering bloom. Coincidentally, the same mild weather that allows winter bloom here also limits autumn foliar color.

However, mild autumn and winter weather does not inhibit the production of the various winter berries. Such berries can either provide extra color while bloom might be scarce, or at least keep migrating and overwintering birds well fed while trying to do so. Many of us actually grow colorful berries more to keep wildlife happy than to provide color. Some enjoy using them like cut flowers.

It is no coincidence that most colorful berries that ripen in winter are small, red, and profuse. Just like flowers use color to attract pollinators, many types of fruits use color to attract the birds that eat them and subsequently disperse their seed. Bright red happens to work best for that purpose, although there are other options. Small berries happen to be easy for birds to grab and go with.

Most of the specie that provide winter berries are related, within the family of Rosaceae, and most are evergreen shrubs. Of these, firethorn, which is also known by its Latin name of Pyracantha, is the most familiar and most prolific with berry production. The various specie and cultivars of Cotoneaster are not nearly as bold with their berries, but provide a bit more variety of plant form.

English hawthorn and related hawthorns happen to be small deciduous trees that defoliate in winter to leave their ripe berries exposed. Incidentally, as their names imply, both firethorn and the various hawthorns are unpleasantly thorny. The native toyon is a big evergreen shrub that can get almost as big as the smaller hawthorns, and has the potential to be pruned up as a small tree. Hollies are not related to the others, and although very traditional, are unreliable for berry production locally.