Mild Seasons

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These daisies are rarely without some degree of bloom.

There is not as much difference between the seasons here like there is in other climates. It might seem like we get only summer, with a briefly cooler and slightly rainy time of ‘not summer’. I can recognize the changing of the seasons because I am familiar with them. Those acquainted with more normal climate mind find our subdued seasons to be rather boring, and restrictive.

People from climates with more extreme weather and more pronounced seasons might not expect mild weather and mild climate to be restrictive or limiting. They tend to notice what grows here that would not survive out in gardens through colder winters, such as bougainvilleas, tropical hibiscus and so many of the popular succulents. Even more tropicals survive farther south.

What they do not notice are what does not do so well here. Although stone fruit does remarkably well here, and many apples and pears are more than adequately productive, there are many cultivars of apple and pear that prefer more chill than they could get here. Lilac gets sufficient chill to bloom well here, but not enough to bloom as splendidly as it does in the Upper Midwest.

For example, some might be impressed by the perennial daisies that bloom sporadically whenever they want to throughout the year here. These daisies take no time off for winter, and are rarely damaged by frost every few years or so. They are so rarely without bloom that it is not often possible to shear off deteriorating bloom without removing some of the unbloomed buds.

What goes unnoticed is the potentially subdued bloom of the forsythias, which are so reliably prolific where winters are cooler. Some are real duds this year, and all are blooming notably late. This is one of the consequences of a mild climate.

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Forsythia, with twigs that are still bare in the background, is not much to brag about.

Daphne

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Bloom worthy of a Scooby Snack

Jeepers!! As Daphne Blake’s colleague, Fred Jones, might say, “Looks like we’ve got another mystery on our hands.” What got into this Daphne odora ‘Aureomarginata’?! It rarely performs so well here, particularly so soon after being planted into a new landscape. This particular specimen, and about three others nearby, were planted as they finished bloom less than a year ago.

Since their season began, I have been commenting to those who share pictures of theirs, that such healthy and prolifically blooming daphne is enviable to those of us who do not live within a climate that is favorable to such performance. I know that this diminutive floral truss is not exactly exemplary compared to those of other regions, but for this region, it is almost spectacular.

The aroma is exquisite! It is everything that the rest of us grow daphne for, and is enhanced by the delightful but unseasonably clear and warm weather. Surroundings forests dampened by rain almost a month ago maintain just enough humidity for the fragrance to disperse. If it were not such a distinct fragrance, I would be wondering where it is originating. It is so unexpected.

Those in other regions believe that we can grow a more extensive variety of species here where winters are relatively mild. For some, that might be true. However, there are many climactic factors that limit what can be grown in every region. Species that require sustained chill in winter are not very happy here. For daphne, minimal humidity might be what they dislike locally.

Perhaps daphne happens to be happy in the particular location, next to a stream that enhances humidity much of the time when there is not much breeze. Perhaps the weather happened to be be conducive to such a performance. Perhaps it will remain a mystery.

Redtwig Dogwood

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Colorful bark for the wintry landscape.

Most dogwoods are popular for spectacular white or pink spring bloom prior to foliation. Redtwig dogwood, Cornus sericea, is an odd one though. It is a ‘dog’wood that is appropriately grown for colorful twig ‘bark’. It blooms later than other dogwoods, and after foliation. The one to two inch wide trusses of tiny pale white flowers lack the flashy bracts that make other dogwoods so colorful.

Another difference is that, unlike more familiar dogwoods, redtwig dogwood naturally grows as a shrubby riparian thicket rather than as a small tree. Long limber branches can grow to more than fifteen feet high only by leaning into other trees or shrubbery. In home gardens, they typically get coppiced or pollarded just before foliating in spring, to develop twiggy growth for color next winter.

After a bit of autumn chill and defoliation, young stems of well exposed wild redtwig dogwood are a delightful glossy ruddy brown. Twigs of garden varieties are richer cinnamon red, rusty orange, soft yellow, orange blushed pale yellow, or yellowish green. Color is subdued by shade. Some cultivars have variegated foliage. Autumnal foliar color is more impressive in more severe climates.

Deciduous Fruit Trees Need Pruning

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Dormant fruit trees will bloom soon.

Deciduous fruit trees have no business in a low maintenance landscape. They need as much specialized pruning while dormant in winter as roses need, and on a much larger scale. Neglected trees get disfigured by the weight of their own fruit. Disease proliferates in their thicket growth that develops without pruning. Overgrown trees produce most of their fruit where no one can easily reach it. Fruit that can not be harvested attracts rodents.

Of course, deciduous fruit trees are certainly worth growing if they get the specialized pruning that they need. Pruning concentrates resources so fewer but better fruits develop. Fruit bearing stems are better structured to support the weight of their fruit, and lower so that the fruit is easier to reach. Pruning also promotes more vigorous growth, which is less susceptible to disease and insects.

Now that it is February, and the weather has been unusually warm, deciduous fruit trees that have not yet been pruned will need to be pruned very soon. They will be sensitive to such major pruning once they start to bloom. The pruning is too specialized to explain here in just a few sentences. Fortunately, Sunset publishes an very detailed book about “Fruit Tree Pruning” that explains how to prune each of the different fruit trees. Pruning will be more extensive each year as trees grow, but also becomes more familiar.

Stone fruits like apricots, plums, prunes, nectarines and peaches (that have hard seeds known as stones), need the most severe pruning. Their fruit develops on stems that grew last year. These stems should get cut short enough to support the weight of the fruit expected to develop next year. The ‘four Ds’, which are dead, dying, damaged and diseased stems, should get pruned out as well. Cherries and almonds do not get pruned as much because their fruit is so lightweight; and out-of-reach almonds simply get shaken down anyway.

Apples and pears are pomme fruits that need similar pruning, but also produce on stunted ‘spur’ stems that should not be pruned away. Spurs may continue to be productive for many years. Figs, persimmons, pomegranates, mulberries and grapevines all need their own specialized styles of pruning.

Pollarding Is Extreme Tree Pruning

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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.

Bulb-Like Perennials For Summer

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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.

Frost Is Just Too Cool

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Frost makes tender foliage ugly fast.

Is it too late to warn about frost? After all the rain, the recent and sudden cold weather was quite a surprise. Fortunately, these recent frosts were relatively mild. This sort of weather is probably just enough to start to satisfy plants that require chilling through winter without causing too much damage to too many sensitive plants. So far, only the most sensitive plants, like angels’ trumpet, canna and left-out houseplants show symptoms of frost damage. (Cannas should get cut to the ground at the end of winter anyway.)

Doing without all frost sensitive plants would be too limiting. Lemon, avocado, bougainvillea, fuchsia and Australian tree fern would be off limits. Such plants are worth growing, as long as we understand the potential for occasional frost damage. Those that are too big to protect may sometimes need to get pruned for removal of stems that get killed by frost. In milder climates, such damage will be very rare. In cooler spots, damage is more common, and may involve a few tougher plants, like jacaranda.

Smaller plants that are sensitive to frost, such as jade plant, angel wing begonia and the various pelargoniums, can be grown in containers so that they can be moved to sheltered spots before the weather gets too cold for them. The most sensitive sorts need to be moved under a porch roof or eave, or maybe into a garage. More resilient plants may be safe under overhanging trees or against a wall. South or west facing stucco walls radiate a slight bit of warmth at night.

Frost sensitive plants that get too big for containers should be planted in sheltered spots, like below eaves or larger trees. If a severe frost is predicted, young plants can be protected by burlap, paper, trash bags or any convenient sheeting suspended above by stakes. Foliage that touches the sheeting may get frozen, but foliage within should be fine.

Foliage and stems that get damaged by frost should not necessarily get pruned away immediately. Although unsightly, the dead foliage insulates damaged stems below from subsequent frost. Besides, premature pruning can stimulate new growth, which is more sensitive to subsequent frost.

HAPPY NEW YEAR!!!

P00101-1January 1, 2020! The first day of the Twenties!

The flora in our gardens north of the Tropics must think we are crazy for making such a fuss about it while they are trying to sleep. Even flora south of the tropics does not understand. All flora everywhere is more concerned with how the seasons change according to the position of the Earth around the Sun. Precise dates, times and numbers are meaningless.

It sort of seems odd to me that within each time zone, it is the same time and date both north and south of the Equator, but the seasons of each side are opposite. Today started in sparsely populated regions of the Pacific Ocean, worked its way through Australia earlier, and is somehow still the same ‘today’ that is here now. Yet it is winter here, and summer to the south.

Now, if January can be in the cool time of year here, and the warm time of year in Australia, it seems to me that winter could be both the cool season here, and the warm season in Australia. If the dates are the same, it seems like the seasons should be too. Alternatively, if the seasons are half a year early or late in opposite Hemispheres, it seems like dates should be too.

According to such logic, it could be either winter or July 1 in Australia and elsewhere south of the Equator right now! . . . But would that be July 1 of 2019 or 2021? Too many technicalities!

Well, it is more than the flora in the garden is concerned about anyway. It is winter here now, and summer south of the Equator. It is the beginning of January everywhere that the Gregorian calendar is used, north and south.

HAPPY NEW YEAR!

Note: ‘Horridculture’ will resume next Wednesday. It did not seem appropriate for the first day of 2020.P00101-2

Winter Is For Dormant Pruning

P90316++++The internet makes it possible to communicate with people who enjoy gardening all over the World. It can be amusing to hear what garden enthusiasts in Australia are doing now in early summer. Is it always summer in Ecuador? A common theme in much of America is that there is not much gardening to do right now. It might be more accurate to say that no one wants to go out in the cold.

Where winter weather is too unpleasantly cold to work in the garden, many winter chores can either be done earlier in late autumn, or delayed until early spring. Such scheduling is not a problem, since the plants involved are so deeply dormant through such cold weather anyway. Until the weather warms a bit, they do not want to work in their gardens either. Scheduling is very different here.

Not only does mild weather facilitate gardening chores, but it necessitates the completion of certain chores before the end of winter. Many plants that are mostly dormant while the weather is cool are actually dispersing their roots now that the soil is moistened by winter rain. They will be ready to break dormancy weeks before they would where winters are colder. There is no time for delay.

With a few exceptions, winter is the season for pruning here. Maples and birches should have been pruned earlier, or should be pruned later, so that they do not bleed sap. Citrus get pruned and groomed after the last frost because pruning stimulates new growth that is sensitive to frost. Early blooming flowering crabapples, flowering cherries and forsythias should get pruned after bloom.

Otherwise, most deciduous plants and many evergreen plants should be pruned in winter, while they are as dormant as they get. Pruning now will be less disruptive than it would be while they are more active. They wake up in spring and resume growth as if nothing happened, but relieved of the superfluous growth that was pruned away. Winter pruning is what fits best into their schedules.

Of all plants in the garden, deciduous fruit trees and roses rely on specialized pruning more than most others.

Some Plants Need To Chill

41210thumbIt is easy to snivel about the weather when it gets uncomfortable for us. The rain gets too wet. The temperature gets too cool. Even here on the west coast, without the cold of Minnesota, the heat of Arizona, the humidity of Louisiana or the rain of the west coast of Washington, we tend to think about weather by limited human standards. What we fail to consider is that many other organisms rely on a variety of weather conditions for their survival.

Deciduous plants make it obvious that they know how to deal with cool winter weather. What is not so obvious that that many deciduous plants actually need specific wintry conditions to be convinced that it really is winter. If the weather does not get cool enough, or stay cool long enough, some plants do not go dormant long enough to get the rest that they need in order to perform adequately the following spring and summer.

For example, the reason that only a few of the many different varieties of apple can be grown locally is that most have chill requirements that exceed what they get here. A chill requirement is a specific duration of cool winter weather. Only a minority of all varieties were bred for their minimal chill requirements, so that they will produce reliably even where winters are innately mild.

Besides chill requirements, some seeds like to be soaked in moist soil before they germinate the following spring. This lets them know that it is raining, like it typically does in winter. Pecans, for example, can be soaked for a while inside before sowing, bur really prefer to be out in the garden through winter, where they can tell than rain water is actually flowing past them through the soil, and the microorganisms in the soil help to break down their shells.

It is all about timing. Chill requirements get apple trees to bloom in spring, only after they were convinced that it was already winter. If they were not so specific, they might bloom after a brief cool spell in autumn, leaving their blossoms or developing fruit vulnerable to later frost. Pecans germinate and grow only after the danger of frost, but before the weather gets too dry. If they start too early, they may not survive frost. If they start too late, they may desiccate through summer.