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.

Posted on by tonytomeo · 2 Comments

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.

Posted on by tonytomeo

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. 

Posted on by tonytomeo · 2 Comments

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.

Posted on by tonytomeo · 6 Comments

Get Bare In Winter

Besides the popular deciduous fruit trees and roses, several deciduous ornamentals, like these clematis vines, are also available bare root.

It may not seem like the middle of winter is a good time for much gardening, but now that any unsold Christmas trees have been removed from nurseries, bare roots plants are moving in. They should be available through the rest of winter, until warming spring weather prompts bloom and emergence of new foliage.

As the name implies, ‘bare root’ plants have bare roots. They are not contained within potting media (soil) in cans or pots. Some are wrapped in coarse sawdust to keep roots moist and contained without much weight. Others are simply heeled into damp sand at nurseries where they can be dug and wrapped when purchased.

Without cumbersome cans, bare root plants occupy less space in nurseries, so many more varieties of fruit trees, grapes, roses, berries and various ornamentals can be available bare root than could be available as standard canned stock during the rest of the year. Bare root plants have the added advantage of costing about half of what canned stock costs.

The main advantage of bare root plants though, is that they waste no time getting established in the garden. The process of getting dug, transported and replanted is done while plants are dormant. When they wake in their new homes in the spring, they immediately start to disperse new roots into the surrounding soil.

If bare root plants can not go directly into the garden once they arrive home, they should be heeled into damp soil or mulch and watered. If planting will be delayed only for a day or two, they can instead be put in a bucket of water to submerge the roots. Plants that are packaged in bags of damp sawdust can wait for more than a week in the shade.

Planting holes need not be any larger than the roots of the bare root plants. If soil is disturbed too deeply, it will only settle and possibly cause new plants to sink. Graft unions (which are evident as kinks low on trunks of trees, or where rose plants branch) should stay above the surface of the soil. Backfill soil should be amended only minimally, or not at all. Too much amendment inhibits root dispersion. (Roots may not want to leave amended soil.) There will be plenty of rain through winter. However, new plants should be soaked twice after planting to settle soil around the roots.

Finally, damaged or unnecessary stems can be pruned off. Bare root fruit trees come with more stems than they need, for padding in transportation, and to allow more options for pruning.

Posted on by tonytomeo

Dormant Pruning Promotes Fruit Production

Persimmon trees get pruned after harvest.

While they are dormant through winter, deciduous fruit trees require specialized ‘dormant pruning’. Exceptions are rare. Most need major pruning that might seem to be excessive. Without such pruning, fruit trees produce more fruit than they can sustain. Excessive fruit is very likely to be of inferior quality, beyond reach, and heavy enough to disfigure limbs.

Dormant pruning limits the volume and weight of fruit that can develop during a following season. By eliminating structural deficiencies and maintaining compact form, it improves the structural integrity of trees. It eliminates diseased stems, and concentrates resources into healthy stems. Dormant pruning concentrates resources into less but better fruit too.

Dormant pruning is necessary because of extensive breeding to improve the quality and quantity of fruit that fruit trees produce. The ancestors of modern cultivars of fruit produce either smaller or less abundant fruit that they can generally support in the wild. However, even some wild fruit trees will produce better fruit with pruning to concentrate resources.

The many various types of fruit trees need various types of specialized dormant pruning. Unfortunately, such trees, which are so commonly available from nurseries, do not come with instructions. It is important to be aware of the sort of maintenance any particular fruit tree will require, prior to incorporating it into a garden. Some dormant pruning is extreme! 

The various stone fruits are the most popular deciduous fruit trees. They are of the genus ‘Prunus‘. Their fruits contain single large seeds, or ‘stones’. This includes apricot, cherry, nectarine, peach, plum, prune, almond and all their hybrids. They need the most intense dormant pruning. (Almond nuts are stones of leathery fruits that are the hulls of the nuts.)

Although uncommon within the mild coastal climates of Southern California, pome fruits, primarily apple and pear, are very popular too. They require specialized dormant pruning that is very different from what stone fruits need. Likewise, persimmon, pomegranate, fig, mulberry, currant, kiwi, grape and cane berries, each need customized dormant pruning.

Posted on by tonytomeo · 3 Comments

The Fruits Of Our Labor

Quince and other fruit used to be much more common in home gardens.

The vast orchards of the Sacramento and San Joaquin Valleys are there for a reason. California is one of the best place in the world to grow fruit trees. However, whether they are in vast orchards or compact urban gardens, even the happiest and healthiest of fruit trees need considerable and specialized attention.

Most of the classic deciduous fruit trees have been bred and selected and bred some more over the past many centuries to produce unnaturally large and abundant fruit. Consequently, most are unable to support the weight of all the fruit that they are capable of producing. This is why it is so important for them to be pruned while dormant through winter.

Pruning improves the structural integrity of fruit trees, and limits the abundance and weight of the fruit produced during the following season. With a bit of planning, pruning can keep much of the fruit within reasonable reach so that those picking it do not need to go dangerously high on ladders. Annual winter pruning also promotes vigorous spring and summer growth that is more resistant to disease.

Apricots, plums, prunes, nectarines, peaches and cherries are all related ‘stone’ fruits (of the genus Prunus), so need various degrees of similar pruning. Peaches need more aggressive pruning because the fruit is so heavy. Cherries and almonds need less pruning because the fruit is lighter. (Almonds can grow beyond reach because the nuts get shaken or knocked from the trees instead of picked.) Regardless of the extent of pruning, the ‘four D’s’, which are ‘dead, dying, damaged and diseased’ stems, should be pruned from all deciduous fruit trees.

Vigorous stems that grew last year need to be thinned and cut back but not removed completely since they are the stems that will bloom and develop fruit next year. The stems that grow from them this year will get pruned next winter to produce the following year. Apples, pears and quinces require similar pruning of their vigorous upper growth, but produce much of their fruit on lower ‘spur’ stems that do not elongate much and may never need pruning.

Fig trees are probably the most tolerant of pruning mistakes, since they produce fruit twice each year. Overly aggressive pruning may compromise their first phase of fruiting, but promotes the second phase. Light pruning does the opposite, compromising the second phase by allowing excessive production of the first phase.

Winter pruning of deciduous fruit trees will undoubtedly seem harsh to a beginner. Trees will need more pruning each year as they grow. Fortunately, pruning becomes more familiar with experience, and as the results of pruning can be observed over time. It is among the most important of gardening tasks for those who grow fruit trees, so is really worth studying more thoroughly.