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Prune now for roses later.

Roses should be pruned before the end of winter. Here where winters are so mild, they can get pruned early.

Just like most of the modern fruit trees that were bred over the past few centuries to produce unnaturally large and abundant fruit, almost all modern roses have been bred for unnaturally large flowers. Production of such large flowers takes quite a bit of work. An excess of these large flowers is more than overgrown rose plants can keep up with. This is why roses should be pruned so aggressively while dormant in winter.

Pruning should be done before buds start to swell at the end of winter. Some people prefer to wait until the end of February. However, because winters are so mild here, buds are already starting to swell, and some are even beginning to grow. I actually prefer to prune early, as soon as roses are dormant and most of the foliage falls off easily when disturbed.

The objective of pruning is to remove as much superfluous growth as possible, in order to concentrate growth into fewer but more productive stems and flowers. Without pruning, roses naturally develop into rampant thickets of abundant but less productive stems. It is also good horticultural hygiene to remove all foliage from last year, since that is where fungal and bacterial pathogens overwinter. Leaves should be plucked from stems and raked from the ground.

Hybrid tea roses get pruned severely so that there are only three to six canes about two feet high. Healthy canes that grew from the base last year are the best. They should have fresh green bark, and preferably lack branches below where they get pruned. Older canes that are developing striations (rough bark texture) should be pruned out. Most floribunda roses can get pruned almost as severely, so that they have only five to a dozen canes.

Some grandiflora roses are allowed to get significantly taller. They develop most new canes on top of canes that were pruned during the previous winter, instead of from the base. Consequently, some stems can get quite old and tall before new basal canes develop to replace them. Climbing roses are likewise pruned less aggressively, since new canes grow from old canes.

Like most fruit trees, most roses are grafted. Therefore, ‘suckers’ (shoots from below graft unions) must be removed. Tree roses should not be pruned below the graft unions on top of their main trunks. Most carpet roses are not grafted, so do not develop suckers; but then, they do not require such specialized and aggressive pruning either.

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Pollarding Pruning Techniques Remain Controversial

Pollarding is pruning to the extreme.

Olive orchards formerly inhabited some of the regions that became urban in California. A few orchard trees remained within urban gardens of the homes that encroached on them. Unfortunately, for those who did not utilize the abundant olives, these trees were horridly messy. Many decades ago, pollarding eliminated the mess without eliminating the trees.

Pollarding is extreme pruning that eliminates all but the main trunk and a few main limbs. It deprives olive trees of their ability to bloom, by eliminating stems of a previous season that would otherwise bloom during the next season. Fruit can not develop without bloom. For other trees that bloom only on older stems, pollarding eliminates bothersome pollen.

Pollarding has several other practical applications. It confines trees that would otherwise get too big for their respective situations. It enhances foliar color and texture for trees that display colorful foliage through summer, such as Schwedler and Princeton Gold maples. Red twig dogwood generates more colorful twigs, and more abundantly, after pollarding.

For agricultural purposes, pollarding generates lush vegetative growth of white mulberry to sustain silkworms, or other vegetation for livestock. It similarly generates long and thin willow stems for basketry. Various eucalypti rely on pollarding to produce juvenile foliage that is colorful and healthy enough for floral design, or aromatic enough for essential oils. 

Nowadays, pollarding is unfortunately passe and even vilified. Consequently, almost no arborists learn about it. Because it is technically disfiguring and potentially unsightly, it is undesirable for many situations. Annual repetition is needed to prevent bloom or fruiting. Otherwise, restorative pruning or more extreme pollarding eventually become necessary. 

For pollarding, proper technique is imperative. Such severe pruning must happen during winter dormancy. It would it be too stressful during vascular activity. Besides, bark would be very susceptible to scald if so suddenly exposed during warmer and sunnier weather. Pruning cuts must be very neat, and back to any old pollard cuts, without stubs to inhibit healing.

Posted on by tonytomeo · 6 Comments

Only Arborists Specialize In Trees.

Big trees need real arborists. Even the best of gardeners should not be expected to perform major specialized arboricultural techniqes.

Just as most problems in landscapes are caused by maintenance gardeners hired to maintain the landscapes, many of the problems with trees are caused by those hired to fix such problems. Arboriculture, which is the horticulture of trees, really should be performed, or at least directed, by professional arborists. It is too specialized to expect it to be done properly by those lacking education and experience.

Even the few proficient gardeners who can perform most aspects of gardening well are not likely as proficient with proper arboriculture as arborists are, not only because it is so different from other gardening, but also because of the techniques and tools involved. Gardeners compare to arborists something like those who clean windows on skyscrapers. Custodians who clean windows on the highest floors from the inside probably would not want to clean the same windows from the outside like window washers do. There are just too many differences in the two related but vastly different types of work.

Arborists who are certified by the International Society of Arboriculture, or ISA certified arborists, are the most qualified to assess the health, stability and structural integrity of trees, and to then prescribe any necessary arboricultural procedures. These arborists have passed an examination of their arboricultural expertise, and maintain their certification by continued involvement with ISA educational seminars, workshops and classes.

Arborists and the tree service businesses that they are affiliated with are easy to find at the website of the ISA at www.isaarbor.com. They can be found directly by name, or regionally by city or ZIP code. The website is also an excellent resource for those wanting to learn more about trees and the importance of proper arboriculture.

Trees are the most substantial features of landscapes, and are really worthy of more respect than they commonly get. Structural problems or instability can be serious problems, not only to the affected trees, but also to anything around them that might be damaged or destroyed by falling limbs or even entire trees. Proper arboriculture helps to keep trees healthy and reasonably safe for many decades or centuries.

Posted on by tonytomeo · 8 Comments

Late Bulbs Require No Chill

Cannas grow after spring bulbs bloom.

Spring bulbs are making a comeback from their unceremonious internments last autumn. Some of the earlier sorts are visibly extending foliage above the surface of the soil. A few narcissus, daffodil and crocus are already blooming! Now it is time to plant late bulbs, or summer bulbs, which start to grow through warm spring weather, and bloom for summer.

Spring bulbs are generally the same as hardy bulbs of climates with cold winter weather. They are hardy to frost while dormant. Since chill is relatively mild locally, their hardiness is irrelevant. Conversely, some prefer more chill than they experience locally. Inadequate chill can compromise performance. Autumn planting maximizes their brief chill exposure. 

Late bulbs are completely different from spring bulbs. Not only do they not require chill to perform, but some dislike it. Many of the most popular late bulbs that can naturalize here succumb to frost elsewhere. Instead of early planting for chill, as spring bulbs prefer, late bulbs prefer late planting to avoid chill. Their foliage emerges after the last threat of frost.

However, although they do not need or even appreciate chill, most popular late bulbs are resilient to the minor chill of local climates. Once established, they simply die back to the ground in response to the first frost of autumn. They maintain dormancy through winter to regenerate for spring. Some repeat this process for years, since the soil does not freeze.

Not all late bulbs are actually bulbs. Most are corms, rhizomes, tubers, tuberous roots, or other bulb-like perennials. Some, such as dahlia and canna, bloom through an extensive season. Some, such as lily and gladiolus, bloom only once. Planting in phases for a few weeks prolongs their bloom. Of course, they will synchronize for any subsequent bloom.

Canna and common white calla are two of the most reliable late bulbs. Crocosmia is too reliable, and since it can be invasive, it is rarely available. Common gladioli and various lilies are spectacular in bloom, but not reliably perennial. Dahlia is a very rewarding and reasonably reliably perennial summer bulb. It is spectacularly variable in color, form and texture.

Posted on by tonytomeo · 8 Comments

Air Layer Overgrown Houseplants.

Air layering big houseplants, like these lanky rubber trees, keeps them proportionate to limited space while also propagating new plants.

Most of the favorite houseplants are grown for dense evergreen foliage. Stems of Chinese evergreen, anthuriums, bromeliads and most ferns should never be seen. Yet, there are many houseplants that grow like small trees or coarse vines. Various ficus, dracaenas and philodendrons can get too big for their situations if not pruned. Palms can not be pruned down, so can only be moved or given to friends with higher ceilings.

Pruning and discarding overgrown but slowly growing stems seems like such a waste. Technically, stems from almost any overgrown houseplant can be rooted as cuttings. In reality though, most rot before they develop roots.

‘Air layering’ is probably the most efficient technique of propagation of houseplants from overgrown stems. It involves rooting the stems while still attached to the original plant. In the end, an unwanted stem gets pruned away as a freshly rooted new plant.

Air layering needs a bare and manageable section of stem that is at least a few inches long. This section does not necessarily need to be where the stem will eventually get pruned away from. It can be a bit higher (or farther out from the origin) if a shorter copy (new rooted plant) is desired. The extra length of stem in between can be pruned out when the copy gets separated.

The stem should be notched up to a third of the way through. This notch will develop roots better if rubbed with rooting hormone. A big wad of wrung out damp sphagnum moss a bit larger than a softball then gets wrapped around the notch, and then wrapped in plastic film. A cut up freezer bag should work nicely. The bag should be held in place with plant tie tape or something as simple as electrical tape, wrapped firmly around the stem above and below the sphagnum moss. Smaller stems can get smaller wads of sphagnum moss.

Unfortunately, there is no way to disguise the unappealing wrapped moss during the few months that may be needed for roots to develop. Eventually, roots become visible through the plastic, or the moss becomes firm with roots. The newly rooted stem can then be cut below the roots, unwrapped and potted as a new copy of the old houseplant. The stub below can be pruned away, or left to develop new shoots.

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Citrus Trees Are Dutifully Fruitful

Citrus are most abundant through winter.

Winter is the primary season for citrus fruits. Some ripen significantly earlier. Some ripen significantly later. Many citrus trees continue to produce a few fruits randomly throughout the year. Nonetheless, citrus fruits are collectively most abundant during winter. It seems odd that trees that are vulnerable to frost are so productive during the coolest of weather.

Citrus trees are fortunately only marginally susceptible to frost in only the cooler climates here. They mostly recover from minor damage where they get a bit too much chill. Those in coastal climates may never experience damaging frost. Some types of citrus are more resilient to frost than others. Vulnerable citrus trees may need frost protection when new.

Home garden citrus trees are different from orchard trees. Most orchard trees, particularly older trees, are ‘standard’ trees. They grow on standard rootstock that allows them to get larger, and therefore produce more fruit than ‘dwarf’ trees. Most home garden citrus trees are ‘dwarf’ trees. They grown on dwarfing rootstock that keeps them dense and compact. 

Furthermore, the many cultivars of citrus that are available for home gardening are more diverse than those that commonly grow in orchards. ‘Lisbon’ lemon is very profuse within season, so is preferable for orchards. ‘Eureka’ lemon, although a bit less productive, may be a preferable option for home gardens because it produces a few random fruit all year.

Now that citrus are in season, some last longer than others. Grapefruit can hang on their trees for months. They actually develop richer flavor with mellowing tartness as they age. Conversely, Mandarin orange and tangerine are the most perishable citrus. Because the rind is loose, their pulp within begins to oxidize after ripening. Lime eventually gets pithy. 

Although this is the time of year to enjoy fresh citrus fruits, it is not the season to do much else with citrus trees. Pruning and application of fertilizer will be more timely after winter. Premature pruning or use of fertilizer is likely to stimulate premature growth. Such growth either languishes through cool weather, or succumbs to mild frost.

Posted on by tonytomeo

Christmas Leftovers

Blue spruce is a good choice for a living Christmas tree, since it can be happy for years in containment.

Just three weeks after Christmas, many of us are already wondering what to do with poinsettias, cyclamens, Christmas cacti, hollies and living Christmas trees. Christmas cacti and hollies are perhaps the easiest of these to accommodate. Christmas cacti do not even need to leave the home as their flowers eventually deteriorate, since they are happy as foliar houseplants or potted on sheltered porches, and with good sun exposure, will bloom annually. Hollies make handsome shrubbery where their prickly foliage will not be a problem. Since some hollies get quite large, and others stay low and compact, it is helpful to know which variety any particular holly plant is.

Cyclamens are popular as cool season bedding plants as well as blooming potted plants. Gardeners typically dispose of those grown as bedding plants as if they were mere annuals. However, they are actually cool season perennials that go dormant through summer. If they are not in the way of warm season annuals in spring, and are among other plants that will cover for them during their dormancy, they can be left in the garden to regenerate and bloom again next winter. Individual potted plants that get too tired to be appealing in the home can be retired to partly shaded shallow ground cover or mixed perennials for a bit of winter color.

Poinsettias are a bit more complicated, which is why so many people simply discard them as they slowly lose their color after Christmas. They can keep their color for many months, and be happy as houseplants, but rarely bloom again in the home once their first bloom is gone. Alternatively, they can be planted into sheltered and partly shaded spots in the garden after frost. Through summer, they develop taller scrawny stems that bloom early in January or so. (Yes, they bloom ‘after’ Christmas.) They are sensitive to frost, so like to be under eaves.

Of all the popular potted plants associated with Christmas, living Christmas trees are the most problematic, not because they are difficult to care for, but because they so often get planted in bad situations. Only the compact conifers, like spruces, junipers and Scots pines, can stay potted to function as Christmas trees for a few years or more. Almost all other pines grow too vigorously to be happy for long in containers. After Christmas, they should instead get their circling roots severed, and then be planted into the garden.

The problem is that most living Christmas trees are Italian stone pines or Canary Island pines, each of which gets much too large for confined garden spaces. If there is not enough space for such a tree to grow to maturity without causing trouble, it best to find another home for it, or to discard it when it outgrows containment.

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Planting Bare Root Stock Properly

It looks like sticks in mud.

Bare root season began as the Christmas season ended. Literally, as the last Christmas trees relinquished their space in nurseries, bare root stock occupied it. Most of this stock grew in Oregon, where winter weather is cooler, so was ready for digging and relocation prior to arrival. Now that it is here, the season for planting bare root stock is quite limited.

Almost all bare root stock is deciduous. It defoliated through autumn, so the stems are as bare as the roots are. Most bare root stock is fruit and nut trees, such as almond, apricot, cherry, plum, peach, apple, pear, persimmon and fig. Grape, currant, gooseberry, wisteria and rose are ready for planting bare root too. All are dormant, so unaware of the process. 

They do not stay dormant for long though. They must be planted in their new homes prior to the end of winter, when warming spring weather stimulates new growth. They can not sustain such growth if their roots are unable to disperse into soil. This is why the season for relocating and planting bare root stock is so limited to winter. It relies on cool weather. 

Fortunately, planting bare root stock is surprisingly simple. Soil amendment that prompts root growth away from confined root systems of canned (potted) stock is not so important. Since new roots grow directly from formerly bare roots into surrounding soil, amendment is only helpful for soil of inferior quality. Fertilizer will not be helpful until growth resumes. 

A hole for planting bare root stock needs to be just big enough to contain the flared roots. It must be shallow enough to suspend any graft union above grade, without loose soil to settle below. Watering is only needed to soak and settle soil around roots, and will not be needed again until after the rainy season. Pruning removes crowded or damaged stems. 

Of course, not all fruit trees are conducive to planting bare root. Evergreen plants are not as dormant during winter as deciduous plants are. Their roots are therefore less resilient to separation from the soil. Pitahaya, avocado and some citrus, which can be marginally vulnerable to frost in some climates, are more vulnerable after autumn or winter planting. 

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Even bare trees have style.

This big perennial ‘sticks of fire’ produces a thicket of bright yellowish orange stems that changes shades through the seasons.

Everyone knows that flowers provide color in the garden, particularly through spring and summer. As blooms become less abundant in autumn, fall color of deciduous plants and trees becomes more prominent. After most plants are finished blooming, and most of the fall color is gone, the garden may seem relatively bleak for winter. Only evergreen foliage remains. This is when plants that exhibit colorful bark or bare twigs really get noticed.

Various types of birch trees exhibit striking white bark all year. While the trees are bare in winter, the bark becomes even more prominent, particularly against a backdrop of evergreen trees. English walnut trees are not as striking, but are more sculptural. Fig trees (fruiting types) are more gray than white, so are more reliant on a backdrop of rich evergreen foliage or a darkly painted wall for contrast; but they grow fast enough to become interesting sculptural specimens within a few years. 

Bright white or light gray bark are certainly no substitute for the colors of flowers or foliage, but are striking nonetheless. They exploit the starkness of winter, and the sculptural nature of bare trunks and limbs.

Even without the sculptural structure of birch, walnut or fig trees, the more colorful twiggy growth of coral bark Japanese maple and osier dogwood trees can be quite an advantage in a stark winter landscape. As the name implies, coral bark Japanese maple has pinkish orange twigs. Osier dogwood can be ruddy brown, brownish orange or pale yellow. Frost improves color.

Unlike other Japanese maples that get pruned only lightly to enhance their form, coral bark Japanese maple can get pruned rather harshly just prior to spring growth in order to promote an abundance of the twiggy growth that is so colorful in winter. Osier dogwoods can get pruned down almost to the ground at the end of winter to eliminate tired older stems and promote colorful new stems for the following winter. They lack the colorful bloom that flowering dogwoods provide; so it is no bother that such harsh pruning prevents them from blooming.

Like trees with white or gray stems, coral bark Japanese maples and osier dogwoods are more striking against a backdrop of rich green foliage. Because winters are so mild here, they should be located where they will be most exposed to chill.

Posted on by tonytomeo · 4 Comments

Bare Root Stock For Winter

Bare roots might fail to impress.

Dormant pruning happens during winter, while the plants that benefit from it are dormant. Obviously, it would not be dormant pruning otherwise. Such processes are less stressful to plants while they are inactive and essentially anesthetized like a surgery patient. This is also why fresh bare root stock becomes available and ready for planting during winter. 

Bare root stock grows on farms for a few years. Any grafting is part of the process. When stock is sufficiently mature, growers dig and separate its roots from the soil that it grew in. Much of the stock goes to retail nurseries for heeling into damp sand for sale. Some gets neat packaging with damp sawdust around its roots. Some goes out for mail order sales.

Regardless of the process, it all happens quickly and early during winter dormancy. Bare root stock must then get into soil again, quickly and before the end of winter dormancy. It will not survive if it resumes growth without soil to contain new roots. Planting should be as soon as possible, so that roots can settle in with rain, and be ready to grow by spring.

Bare root stock is less expensive than canned (potted) stock because it is so lightweight and easier to process. Since it occupies less space than canned stock in retail nurseries, more varieties of bare root stock are available. Bare root stock is easier to load into a car, and plant into a garden. Once in a garden, it disperses roots quickly and more efficiently.

Deciduous fruit trees are the most popular bare root stock. Of these, most are stone fruits or pome fruits. The stone fruits, of the genus Prunus, include cherry, plum, prune, apricot, peach, nectarine, their hybrids, and almond. Apple, pear, and quince are pome (pomme) fruits. Pomegranate, persimmon, fig, mulberry and walnut are somewhat popular as well. 

So much more than deciduous fruit and nut trees are available as bare root stock. Grape, kiwi, currant, gooseberry and blueberry are deciduous fruiting vines or shrubs, not trees. Blackberry, raspberry and strawberry are evergreens. Rhubarb, asparagus and artichoke are perennial vegetables. Rose, wisteria, hydrangea and so many more are fruitless ornamental plants.