Most Pruning Happens In Winter

30206thumbWithout specialized pruning while they are bare and dormant in winter, many deciduous fruit trees would be overburdened by their own fruit next summer. The production of excess fruit can waste resources. The weight can disfigure and break limbs. The trees certainly do not want to get so overworked; but they have been unnaturally bred to produce bigger, better and more abundant fruit.

Proper pruning of dormant fruit trees improves the structural integrity of the limbs, and limits the weight of fruit that will develop on the remaining stems. This might seem to be counterproductive, but it is the only way to keep limbs from breaking or growing so high that the fruit is out of reach. It also concentrates resources into fewer but superior fruit, instead of more fruit of inferior quality.

Dormant fruit tree pruning can not be adequately described in only a few paragraphs. Yet, it is so important and so specialized that anyone wanting to grow fruit trees should learn about it. Each type of tree requires a particular style of pruning. Something they have in common is that the ‘four Ds’, which are ‘Dead, Dying, Diseased and Damaged’ stems, obviously need to be pruned out.

The various stone fruit trees (which are of the genus Prunus) need various degrees of a similar style of pruning. Heavy fruit, like peach and nectarine, necessitate more aggressive pruning than does lighter fruit, like plum and prune. Lighter fruit is easier to support. Some cherry and almond trees may not need to be pruned every year. (Almonds are ‘stones’, and their hulls are the ‘fruit’.)

Flowers of next spring and fruit of next summer will develop on stems that grew last year. These stems need to be pruned short enough to support the fruit that can potentially develop on them. If too long, they will sag from the weight of the fruit. If too short, they will not produce enough fruit. Stems that grow beyond reach can be pruned even more aggressively to stimulate lower growth.

Apple and pear trees also produce on the stems that grew during the previous year, but produce more on short and gnarled spur stems that continue to produce for many years without elongating much. Therefore, the tall vigorous stems that reach upward, particularly from upper limbs, can be cut back very aggressively if necessary. Aggressive but specialized pruning keeps trees sturdy and contained, and also improves the quality of fruit production.40101thumb

Collecting Seeds For Next Year

80110thumbWhere winters are cooler, the deteriorating stems of flowers that bloomed last year either got pruned away already or got knocked down by the weather, and are now rotting on the ground. Around here, where the weather is milder, and some flowers only recently finished blooming, used up flower stalks still stand in stasis. Most but not necessarily all should get pruned out and raked away.

Dahlias succumb to frost as soon as it arrives. If not already cut back, they fall to the ground like steamed spinach, and should get raked up and put into greenwaste. There is nothing to salvage. Sunflowers are related to dahlias, but do not collapse so easily. Even if they are not pretty, those that produce seed can be left for whatever birds like to eat them, and then recycled when empty.

Of course, not all of the seed must be left to the birds. Some or all can be saved for next year. The flowers only need to be allowed to dry so that the seed matures. If the birds start to eat them first, old flowers can be cut and stored in open bags or boxes in a shed or garage, out of reach of birds. Stems should be cut longer if they are still green. Seeds should fall from the flowers as they dry.

Seed can also be collected from lily-of-the-Nile and African iris, although these perennials are so easy to propagate by division that growing them from seed might be more trouble than it is worth. Their seed capsules must be allowed to dry, just like sunflower seed. Belladonna lily makes a few weirdly succulent seed that are worth collecting. Some primitive cannas make weirdly hard seed.

It might be worth researching flowers that happen to be in the garden to determine if they produce viable seed worth collecting. It is also important to know what seed requires scarification or stratification. Seed that needs stratification must be exposed to cold temperatures to be convinced that it is time to germinate in spring. Canna seeds need to be scarified by filing through the hard shells before they germinate. Other seeds need other types of scarification or stratification.

Bare Root Stock Has Advantages

31225thumbAnyone who has had undergone surgery knows the advantages of unconsciousness. Any frat boy who woke up after a night of overly indulgent inebriation, with his face adorned with objectionable graffiti, knows the disadvantages. A lot can happen while one is unaware that it is happening. This is exactly why so many bare root plants become available while they are dormant through winter.

Bare root plants get dug and deprived of the soil that their roots grew in, leaving the roots bare. Some get their roots packaged into bags of damp sawdust. Others get their roots heeled into bins of damp sand in retail nurseries. Roots are only bagged or heeled in to stay fresh. They get pulled from their sand or separated from their bag of sawdust when ultimately planted into the garden.

It might seem violent, but it all happens while the plants are dormant and unaware of what is happening. They go to sleep happily rooted into the ground wherever they grew, and then wake up in a home garden somewhere else. It only takes a short while to get reoriented before they develop new foliage and new roots as if nothing ever happened. The whole process is surprisingly efficient.

Canned (potted) plants are actually less efficient in some ways. They are bulkier and therefore more difficult to bring home from the nursery. Their confined roots are more likely to be disfigured or binding. (Roots that wrap around the inside of a can will constrict on themselves as they grow.) The media (potting soil) could contain disease. Worst of all, canned stock is much more expensive.

Bare root plants are remarkably easy to plant. Their planting holes only need to be big enough to contain the roots. Soil amendment should be minimal. If too much amendment is added, or holes are too deep, new plants are likely to sink. Graft unions (the distinctive ‘kinks’ just above the roots) of grafted trees must remain above grade. Roots should be spread out laterally and downward.

Smaller bare root plants like cane berries, grapevines, gooseberry and currant are already moving into nurseries where Christmas trees are relinquishing their space. Fruit trees like apricot, cherry, plum, prune, peach, nectarine, almond, apple, pear, quince, fig, pomegranate and persimmon will arrive next, followed by blueberry and roses. Poplar, flowering cherry, flowering crabapple, forsythia, lilac, wisteria, rhubarb, strawberry and asparagus might also be available.

Potted Plants For Christmas Color

80103thumbAfter all the Christmas decorations get put away for next year, and the Christmas tree eventually gets undressed from all its ornaments, and retired to the compost pile or greenwaste, all the pretty seasonal potted plants remain. Some will bloom, or at least maintain their current bloom, for months. Some might eventually get planted out in the garden. Others might stay potted in the home.

Poinsettias are the epitome of seasonal potted plants for Christmas. Their flashy red bracts last a very long time, even after the tiny yellow flowers are gone. Some are pink, white, pale yellow, peachy, marbled or spotted. They can be grown as foliar houseplants, but will not likely bloom next Christmas. If protected from frost in the garden, they get tall and lanky, and bloom in January.

Christmas cactus is an excellent potted plant either indoors or out where protected from frost. The pendulous growth cascades nicely from a hanging pot. It blooms in phases, but does not stick to a tight schedule. Amaryllis should also stay potted only because it does not do well in the garden over winter. Foliage that develops after bloom will die back next autumn before bloom next winter.

Holly and azalea can be planted directly into the garden where appropriate. Azalea will probably look shabby until it gets new growth. Cyclamen is a perennial in the garden, but dies back over summer. It just might come back with a surprise in autumn. Paperwhite narcissus is perennial too, but exhausts its resources on bloom, so takes a year or more to recover before blooming again.

Small living Christmas trees are more variable than they seem. Rosemary can either be kept potted and shorn, or planted into the garden and allowed to grow wild or into another form. Dwarf Alberta spruce can likewise stay potted or get planted into the garden, but needs no shearing. Both rosemary and dwarf Alberta spruce will want larger pots as they grow. Italian stone pine and Canary Island pine grow into large shady trees, so should only be planted into spacious landscapes that can accommodate them.

Unseasonable Weather Can Confuse Plants

70920thumbEven without any of the five senses that we are outfitted with, plants are remarkably perceptive of the weather and the changing seasons. They know precisely what time of year it is because they know how long the sun is up. Their calendar is just as accurate as ours is. They also know that the weather has been getting progressively cooler through autumn, and that it rained a bit earlier.

New Zealand tea tree, torch lily, euryops daisy and many other plants from other temperate climates do not seem to care that they should not be blooming at this time of the year, if the weather is telling them otherwise. If the weather is warm enough during the day, even if it gets cool at night, these plants will bloom right up until things get really cold, even if some of their bloom gets frosted.

Saucer magnolia, lilac, apple and the many other plants from climates with cooler winters should know better than to bloom this time of year. Many bloom only once annually, so whatever blooms now will not bloom when it should next spring. Besides, the flowers that try to bloom now will bloom slowly, and probably be ruined by cool or rainy weather before they can develop completely.

Roses had a particularly weird year. They bloomed well and on schedule last spring, but then idled through much of summer, only to express a new interest in blooming now that they should be going dormant for winter! No one wants to prune them while they have more buds than they did in August. Fortunately for them, they bloom more than once annually, so should recover by spring.

The colorful foliage of sweetgum and Chinese pistache, as well as the observable weather, indicate that everything is more or less in order for this time of year. Autumn might have started out mild, but it had been even warmer in past years. It is impossible to say why some magnolia, lilac and apple are trying to bloom already. They each have such distinct personalities, and respond to so many different variables besides the obvious; daylength, temperature and humidity.

Jack Frost Was Sneaky Again

71227thumbTiming is very important in gardening. Even when the weather in autumn still seems like summer, spring blooming bulbs must be planted on time. Bare root fruit trees will become available while they are dormant, and will need to be planted before they wake up. Roses need to be pruned before buds for new canes swell later in winter, even if their old canes are still awake and blooming.

Some procedures are influenced more by environmental factors than timing. Planting bare root fruit trees and pruning roses must be done sooner if the weather gets warm sooner than expected. Irrigation must be increased in summer, but only as warm and dry weather necessitates such increase. It gets decreased in winter, but only as weather gets cooler and rainier. Then there is frost.

Frost arrives differently every year, and is of course worse some years than others. It is only a minimal threat in some regions, but limits what can be grown in others. It happened to be sneaky this year, by hiding in between remarkably pleasant days. While the daytime weather is so mild and even unseasonally warm, a weather forecast may provide the only early warning of overnight frost.

By now, sensitive plants were either protected successfully, or possibly damaged by earlier frosts. Potted plants got moved to shelter under porch roofs, or maybe dense evergreen trees near the home. Those in the ground might have been tented with plastic or sheeting suspended above the foliage by sticks and maybe string. Old fashioned Christmas lights might have softened the chill.

Many perennials and annuals are just left out to succumb to the cold. Any remaining warm season vegetable plants are not worth protecting. They will not produce anything this late anyway. Canna and ginger can likewise be left out in the cold for their foliage to freeze and collapse to the ground. If protected, they can stay green through winter, but will replace their foliage in spring anyway.

Foliage of hosta and dahlia can be removed because the dormant parts of the plants are safe below the surface of the soil. Canna and ginger rhizomes on the surface of the soil might appreciate a bit of mulch if their foliage gets removed. Frost damaged stems of woody plants should not be pruned out too early. Premature pruning stimulates new growth that will be sensitive to later frosts.

Rodents Eat Just About Anything

61214thumbNot much bothers old fashioned junipers. They tolerate heat and frost, and anything else the weather throws at them. They do not appeal to many troublesome insects. Once established, they do not mind if they do not get much water. So, aside from over-watering and bad pruning, they are pretty indestructible. Yet, once in a while, otherwise healthy junipers die suddenly and mysteriously.

Sometimes, entire plants die. Sometimes, only big pieces of them die. The foliage is intact, but dried to a nice light brown. The roots are firm. In fact, the damage that caused such efficient death might not become apparent until the dead stems get dismantled and removed. It might even get overlooked because it is not the sort of damage that we expect to find in our tame home gardens.

Rats! They sneak in under the dense foliage to chew the bark from the main stems. The thicket of rigid stems protects them from cats and dogs. They can kill both shrubby and ground cover junipers, as well as ivy, ceanothus, cotoneaster, firethorn, . . . and nearly any sort of shrubby plant that they feel safe from predators in. They also eat vegetables and fruits, particularly citrus fruits.

The damage should be rather distinct. Bark is missing. Bare wood is exposed. Squirrels sometimes cause the same sort of damage, but usually on smaller stems in trees. Gophers do their dirty work underground by eating roots. If they kill junipers or other shrubbery, the dead plants can be pulled up from the soil relatively easily, and fresh gopher ‘volcanoes’ should be evident in the area.

Protecting stems and roots from rodents is more difficult than protecting developing fruit. The rodents know that they are concealed by the dense growth that they chew the bark or roots from, so fake owls are not much of a threat. Poisons are very unpleasant for the targeted rodents (duh!), and very dangerous to cats and dogs that might catch the poisoned rodents. Traps are effective and safe (except for the rodents . . . duh!) but take serious dedication to empty and reset!

Christmas Trees And Cut Foliage

31211thumbThere should be no guilt associated with a cut Christmas tree. They were stigmatized many years ago, when some people believed that they were harvested from forests, and more of them likely were back then. However, most of us now know that, except for a few that actually are harvested from the wild, Christmas trees are grown on farms like most other cut foliage or horticultural crops.

That is how Christmas trees get their nice Christmas tree form. Only spruce and a few types of firs grow so densely and symmetrically in the wild; and spruce are not commonly cut as Christmas trees. Almost all types of Christmas trees need to be pruned or shorn for density, symmetry and maybe even form. Most of the foliage for wreaths and garlands is likewise grown on foliage farms.

Contrary to popular belief, living Christmas trees are no more environmentally responsible than cut trees are. They are farm grown and artificially irrigated exotic (non-native) trees in vinyl cans filled with synthetic media (potting soil) and synthetic fertilizers. Just like cut trees, they need to be shorn unnaturally. Then, after all that effort, most die and get discarded after Christmas anyway.

Those that survive are usually more trouble than they are worth. Because they are exotic, they should not be planted out in the wild. Because their roots are confined, they would not survive without irrigation through the first year anyway. A few types that grow slowly and maintain density might stay potted and be brought in at Christmas for a few years, but that requires diligent maintenance.

The worst problem with living Christmas trees is that they often get planted into home gardens that can not accommodate them. Few people know what kind of tree their living Christmas tree is, or realize how big it can get. Some trees are Italian stone pines or Canary Island pines, which simply get too large. Even junipers, arborvitaes and smaller pines need adequate accommodations. Arborists can attest to damage caused by living Christmas trees in bad situations.

The Secret Affairs Of Flowers

61207thumbThere are some things about plants that we might be better off not knowing about. For instance, their idea of sex is even weirder than that of humans! Generally, flowers of ‘monoecious’ plants have male parts and female parts that do what they must to produce seed, which is often contained in some sort of fruit structure. Some plants can pollinate themselves. Ick! Others require separate but compatible pollinators.

Some plants bloom with both but separate male and female flowers. Female pine cones that produce seed are very different from the male pine flowers that produce pollen. Female flowers of spruce and several other conifers bloom higher in the canopy than male flowers. This promotes better cross pollination, since pollen must be blown upwardly but relatively randomly to the cones instead of simply falling from above.

Dioecious plants might seem less . . . weird. They actually have separate genders. Some are female. Some are male. Female plants require pollination from male plants in order to produce seed and fruit, though some can provide a few of their own male flowers if they sense a lack of males in the neighborhood. Ick again! There are certain advantages to every method of pollination, whether it makes sense to us or not.

One advantage of dioecious plants that does make sense to us is that messy fruit can be prevented by growing one gender or the other. Modern cultivars of Chinese pistache and maidenhair tree (gingko) are male, so can not produce the messy fruit that older trees are notorious for. Female date palms recycled from old date orchards are unable to produce dates without the male pollinators that do not get recycled.

However, this is a disadvantage if holly can not make berries because it lacks pollinators. Decades ago, scions (stems) of male holly were grafted onto female plants. Alternatively, male plants were sold along with female plants.

Winter Is The Season For Pruning

71213thumbNow that winter is only two weeks away, and many deciduous plants are defoliating and dormant, it may seem as if there will be less work to do in the garden. After all, not much is growing. The funny thing is that this is the best time to sneak up on some of them, and prune them while they are sleeping. Depending on what is in the garden, winter can be just as busy as any other season.

There are a few things that should most certainly not be pruned in winter. Maples and birches should either be pruned before or after winter. They bleed profusely if pruned in winter. Plants that bloom in winter or early spring should be pruned after they have finished blooming. Pruning forsythias, flowering cherries and flowering crabapples earlier will remove much of the blooming stems.

Deciduous fruit trees are of course an exception to that rule. They require annual winter pruning so that they to do not produce too much fruit. Excessive fruit is of inferior quality, and can break limbs. It is acceptable when pruning fruit trees to leave a few unpruned stems to cut and bring in later, as long as they are not forgotten. They can be less refined alternatives to flowering cherries.

Once we determine what should not be pruned in winter, it is easier to see that most deciduous plants should be pruned while bare in winter. Elm, oak, poplar, willow, mulberry, pistache, gingko, crepe myrtle and most popular deciduous trees are sound asleep and unaware of what might happen to them for the next few months. They would be pleased to wake already pruned next spring.

Some evergreen plants should probably be pruned as well. Tristania, redwood, podocarpus, Carolina cherry, bottlebrush and the various eucalypti would prefer to be pruned while the weather is cool. Conifers bleed less this time of year; and pine and cypress are less susceptible to pathogens that are attracted to wounds during warm weather. Avocados and citrus, particularly lemons, should not be pruned in winter, because pruning stimulates new growth which is more sensitive to frost.