Summer Bulbs After Spring Bulbs

Summer bulbs start late in winter.

It was easy to bury spring bulbs so discourteously in shallow graves last autumn. None of them got proper funerals. Perhaps cool season annuals obscured their interment sites. No one needed to know they were there. It seemed like a perfect crime, until now. They are back like the undead. After all, they were not dead when interred. They were merely dormant, and likely plump and healthy.

Crocus, snowdrop, narcissus and some of the other related daffodil might already be blooming. Otherwise, their foliage is emerging above the soil. They do not necessarily wait for the soil to get warmer later in winter. Hyacinth and tulip will bloom a bit later. Delayed planting delays bloom, but only for the first season. Established spring bulbs from previous seasons will bloom as they like.

Spring bulbs, including corms, rhizomes, tubers and tuberous roots, prefer early interment for a reason. They appreciate a good chill through winter. Although most get refrigerated artificially prior to sale, they certainly do not mind a bit more chill. Besides, they also appreciate early root dispersion, even while still dormant. They prefer to bloom early, but unfortunately, also finish bloom early.

Summer bulbs are very different. They go into the garden later because they do not require chill. Furthermore, many types are sensitive to minor frost if they begin to grow too early in winter. Since they start growth later than spring bulbs, summer bulbs generally bloom later. However, some bloom for extensive seasons. A few summer bulbs bloom from early summer until frost in late autumn.

Dahlia, canna and old fashioned white calla are the more reliable of summer bulbs to plant now. Old fashioned white calla may be rare in nurseries. Smaller, more colorful, but less vigorous callas are more popular. Such summer bulbs are more sustainable than spring bulbs, and can perform for many years. Gladiolus and various lily are spectacular summer bulbs, but bloom once annually.

Incidentally, unlike the spring bulbs, most summer bulbs are actually corms, rhizomes, tubers or tuberous roots.

Six on Saturday: (Two is Enough)

Six on Saturday is about gardening. It should therefore feature flowery pictures. I do sometimes try to comply, but often neglect to include flowery pictures. I included one for this week, and two more horticulturally oriented pictures. Of course, the most important picture is of Rhody; because everyone loves Rhody. The other two pictures are neither horticulturally oriented, nor relevant to Rhody. I just found them appealing.

1. Rhody is who you came here for. I did not even bother saving the best for last this time. Do you really need to see the other five? I am sorry that he does not cooperate for better pictures.

2. Prunus bloom provides a flowery picture. This and the picture of Rhody are all my Six on Saturday needs. I do not know what species this is. It was understock of a tree that got cut down.

3. Daffodil bloom after other narcissus, so typically get thrashed less by wintry weather. Each year is unique though. Paperwhite narcissus bloomed before stormy weather started this year.

4. Palms do not dominate all of the landscapes of California. Although they are common near the Coast of Southern California, they are uncommon, and look weird, here among the redwoods.

5. Lichens are not exactly relevant to horticulture. I just happened to notice how uniformly these lichens cover this fence. If they were greener, they might resemble a squarely shorn hedge.

6. Bean Creek flowing from the top of the picture into Zayante Creek is irrelevant to horticulture as well. I just happened to like this picture of this bit of the forest. Bean Creek flows through the Farm just a few miles away. Ferndell Creek is barely visible where it flows into the middle of this picture from an unseen waterfall to the right. Miley Cyrus was filmed there for ‘Malibu’.

This is the link for Six on Saturday, for anyone else who would like to participate:

https://thepropagatorblog.wordpress.com/2017/09/18/six-on-saturday-a-participant-guide/

Winter Is Time For Pruning

Pomegranate trees appreciate major specialized pruning.

Plants are unable to migrate to warmer climates for winter like so many migratory birds do. They are immobile for their entire lives. Only potted plants can move to more sheltered situations when the weather gets too cool for them. Some get to live inside as houseplants. Otherwise, they all must contend with seasonally changing weather. Most are impressively efficient with how they do so.

Most that do not adapt efficiently to cool winter weather are tropical species. Tropicals that are native to high elevations can tolerate cold weather. However, many of the familiar tropical species are from low elevations where they never experience cold weather. Frost damages or kills them. Warm season annuals do not tolerate cool weather either. They just die at the end of their season.

Otherwise, almost all other plants go dormant through winter, at least to some degree. Even evergreen plants, which may not seem to go dormant, grow much slower during winter, or do not grow at all. Deciduous plants are much more obvious about their dormancy, because they defoliate. While bare, they are less susceptible to damage from wintry weather. Dormancy is like hibernation.

This is why winter is the best time for pruning most plants. While dormant, they are less susceptible to distress associated with pruning. Some plants expect some degree of damage from wintery weather during their dormancy anyway. They wake in spring, with no idea of what happened while they slept, and resume normal growth. Winter pruning conforms quite naturally to their life cycles.

There are, of course, a few exceptions. Citrus and avocado should not be pruned during winter. Such pruning stimulates new growth, which is sensitive to frost. Maple and birch should have been pruned earlier. They bleed annoyingly if pruned late into winter. Flowering trees that produce no fruit, such as flowering dogwood and flowering cherry, should be pruned after bloom, late in spring.

Deciduous fruiting trees, such as apricot, cherry, plum, peach, apple and pear, require specialized pruning during winter.

Mild Seasons

P00307K-2
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.

P00307K-1
Forsythia, with twigs that are still bare in the background, is not much to brag about.

Daphne

P00215K
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

00219
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

00122thumb
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

50128thumb
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

00205thumb
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

31218thumb
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.