Norfolk Island Pine

Norfolk Island pine seems to have been built rather than grown.

            In coastal areas of Southern California, the Norfolk Island pines, Araucaria heterophylla, are among the most distinctive large trees. Perhaps they are better described as ‘unusual’ . . . , or even ‘strange’. They are so symmetrical that they seem to have been assembled from prefabricated kits than to have grown as natural trees. Their strictly organized conical branch structures and remarkably straight central trunks are always visible through their uniformly open canopies. In such mild climates, they can get nearly a hundred feet tall and half as wide, so are not easy to hide. In Hawaii, their symmetry has actually made them popular as Christmas trees. Their finely textured juvenile foliage is comprised of narrow, half inch long pine-needle like leaves, which are wider among adult growth.

            Locally though, Norfolk Island pines are primarily enjoyed as houseplants, particularly since they can grow slowly and live in pots for many years. The climate is just a bit too cool in winter for them to be very happy in the garden. However, as they eventually get too large for their homes, many end up in the garden anyway. They stay much smaller and are not nearly as symmetrical as they are in milder climates, and may be damaged by the more severe frosts every few years, but they have a certain appeal and distinction regardless. Those that get planted in the garden while young seem to be more symmetrical than those that get disfigured by living as houseplants longer. For some reason, trees that develop weak or curved trunks as houseplants tend to continue to grow with interestingly irregular trunks and branch structure.

Frost Protection

For many species, frost damage is not as bad as it looks.

            My colleague in the Los Angeles area still sends me seeds for all sorts of strange plants that I probably should not be growing in my less climactically temperate garden, making it difficult to conform to the primary rule of frost protection: ‘Select plants that are appropriate to the particular climate.’ No matter how often I remind my clients of this rule, I really do not want to abide by it. There are just too many interesting but inappropriate plants.

            So the next option is to grow frost sensitive plants in containers that can be moved to sheltered areas prior to frost. That worked while I had an extra parking space in the carport and some room under the porch for giant bird-of-Paradise, plumeria, philodendrons and such. Eventually though, some of these plants get too large to be contained; and I really do not want to keep pruning them back. Besides, I prefer to grow things in the ground.

            The third option is to put sensitive plants in spots that are naturally warmer, or where they are sheltered below the canopies of large evergreen trees, lath or wide eaves. Just remember that plants under eaves are also sheltered from rain, so may need to be watered occasionally through winter. Steep slopes are not quite as cold because cold air drains off. However, flat areas below slopes get colder as they catch cold air that drains from uphill. South facing exposures are of course warmer than northern exposures.

            I know probably better than most that there are always some plants that are not ‘appropriate to the particular climate’, that I do not want to grow in pots, and that prefer to be out in exposed parts of the garden. For example, bougainvilleas are somewhat tender, have sensitive roots that do not like to be confined, and really want to be out in the open to take advantage of warming sunshine during summer. Such plants in colder areas will either need to be protected, or will get damaged by frost.

            Burlap suspended above the foliage by stakes is typically enough to protect sensitive plants from frost. I have used old towels and linens where my neighbors can not see. Plastic sheeting is also effective, but should be removed before sunlight warms the air too much underneath. Paper grocery bags or cardboard boxes are enough for small plants.

            I actually allow some of my larger plants that would be difficult to cover to get damaged by frost, and then prune out the damage later. If they are too big to cover easily, they are probably big enough to survive frost. Damaged stems should be left until the end of winter both to insulate stems below, and also because early pruning stimulates new growth that is even more sensitive to frost. 

Pollinator

A pollinator is a vector of pollen, besides wind. Most are insects. Some are animals. Their only qualification is that they collect and deliver pollen between flowers. Almost all are unaware that they do it as they visit flowers for nectar, which the flowers produce to attract pollinators. Bees, which are probably the most common pollinators, visit flowers to collect pollen with which to make their honey, and pollinate in the process.

So, what about the flowers that provide pollen for pollination, particularly for dioecious species such as hollies, date palms and kiwi vines? (Dioecious plants are either male or female.) ‘Bing’ cherry is not dioecious, but is not self pollinating either, so needs another cultivar of sweet cherry for cross pollination. Such a cultivar is known as a pollinator.

My female kiwi vine just recently acquired a male pollinator. It does not look like much yet, but will grow up to bloom with male flowers to provide pollen for the female flowers of the vemale vine. Because kiwi vines are dioecious, the female vine would be fruitless without pollination from the male vine. Perhaps the male pollinator will need a pollinator to deliver its pollen to the female vine.

Atlas Mountain Palm

Atlas Mountain palm resists frost damage.

Mediterranean fan palm is a shrubby palm, with a few small trunks. Atlas Mountain palm, Chamaerops humilis var. argentea, is an even shrubbier variety. Mediterranean fan palm can grow slowly to about twenty feet tall. Atlas Mountain palm grows even slower to only about eight feet tall. Its several trunks become strikingly sculptural only after many years.

The primary allure of Atlas Mountain palm, though, is its distinctly silvery gray foliar color. Individual fan shaped leaves may be nearly two feet broad, with deep and narrow clefts. Petioles are so nastily thorny that grooming and pruning can be painfully difficult. Mature trunks can be six inches wide with dense coats of petiole bases. Bloom is not prominent.

Atlas Mountain palm is notably undemanding. Once established, it does not crave much water or fertilizer. Nor is it finicky in regard to soil quality. It is resilient to both extremes of heat and cold. After several years, it might benefit from thinning of superfluous trunks and pups. Like many palms, Atlas Mountain palm should perform well within big pots or tubs.

Frost Is Not An Enemy

Among canna, frost damage is harmless.

Rain was one clue. Cooler weather is another. It is now so late into autumn that it will be winter soon. Every regional climate experiences some degree of chill. Some, particularly to the north, experience frost. This limits gardening in two ways. Several species prefer a bit less cool weather. Several prefer a bit more. Every species prefers a particular range.

Apple trees, for example, require vernalization, which is a specific duration of chill. Some cultivars require more than others. Without it, they can not distinguish seasons, so do not know when to bloom for spring. Consequently, few cultivars of apple perform adequately within Los Angeles. However, many perform very well in the cooler climates of San Jose.

Banana trees, conversely, need no chill, and are instead set back by frost. Some tolerate a bit more chill than others; but ultimately, they are all tropical species. They produce fruit only within the months between frosts. Consequently, not many banana trees are notably productive within San Jose. However, they perform better in the climates of Los Angeles.

Banana trees stop growing when the weather is cooler than fifty degrees or so. That is a bit too much chill for them. However, frost does not occur until the weather is cooler than thirty-two degrees. Banana foliage can therefore be safely dormant during chilly weather. That is a range of twenty-two degrees. Different tropical species survive different ranges.

The simplest form of frost protection is to not cultivate species that are vulnerable to frost. This is, of course, a bit too restrictive for many who enjoy gardening. Instead, some grow vulnerable species in pots to move to shelter prior to frost. Some simply grow vulnerable species below the shelter of eaves or big trees. Tenting may also be effective protection.

Alternatively, some species can endure frost damage to recover during warmer weather. If possible, outer foliage that succumbs to frost should remain through winter. It insulates inner growth from subsequent damage. Besides, premature grooming can stimulate new growth that is more vulnerable. Many perennials prefer cutting back after winter anyway.

Six on Saturday: Ferns

After the warm and arid summers here, ferns enjoy the beginning of the rainy season in late autumn or early winter, which is about now.

1. Adiantum capillusveneris, Southern maidenhair fern replaces all its tired old foliage for autumn. It resembles native species of maidenhair fern, but with distinct foliar form.

2. Nephrolepis cordifolia, sword fern remains within a big pot because it can be invasive in the ground. It is directly related to Boston fern, but is not quite as soft and pendulous.

3. Dryopteris erythrosora, autumn fern is the only fern here that exhibits autumn foliar color. It is pretty, but quite diminutive. It is no bigger now than it was several years ago.

4. Polystichum munitum, Western sword fern and the next two ferns are native here. All three grow wild within some of our landscapes; and all are remarkably tolerant of shade.

5. Athyrium filixfemina, lady fern is also known locally as ostrich plume fern, but is not related. It has tender leaves with almost succulent rachises that break easily if disturbed.

6. Woodwardia fimbriata, giant chain fern has a similar foliar texture, but is bigger and more resilient than lady fern. We sometimes need to remove big superfluous specimens.

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/

White Alder

White alder has a distinctive silhouette.

During the summer, the native white alder, Alnus rhombifolia, is a nice shade tree that looks bigger than it really is. By late winter, the bare deciduous canopy has an appealingly picturesque silhouette. This time of year is actually when white alder is typically less appealing, with dead foliage that provides no interesting fall color, but lingers until knocked down by rain or late frost. Yet, even now, it sometimes surprises with these funny looking floral structures that are interesting both in the early winter landscape, and with cut flowers.

In past decades, white alder was an ´expendable’ tree that was put into landscapes for quick gratification while slower but more desirable trees matured. By the time the desirable trees matured, the alders were removed to make more space for the desirables. This technique was practical because, like many fast growing trees, alders do not live very long, so start to deteriorate after about twenty five years anyway. However, alders often live longer than expected.

Mature alders are usually less than fifty feet tall where they are well exposed. They can get at least twice as tall where shaded by other trees or big buildings. Their plump trunks with mostly smooth silvery gray bark make them seem larger than they really are though. Too much water promotes buttressed roots which can displace pavement.

Bare Root Stock

Bare Root Stock may not be much to look at.

Now that nurseries and garden centers are no longer selling Christmas trees, they have plenty of room for bare root stock. All sorts of deciduous fruit trees, a few deciduous shade trees, shrubs and vines, and even a few perennials can now be purchased while dormant and without the cumbersome media (soil) that the roots need at all other times of the year. Not only is bare root stock easier to handle and transport in small cars, but it is also much less expensive than canned stock (that has roots contained in media, which is contained in nursery cans). Bare root stock typically costs about a third of what canned stock costs.

Bare root stock also has the advantage of adapting to new garden easier, since it does not need to leave the comfort zone of the media that it would have grown into (within a can) in order to venture out into unfamiliar soil. Instead, it starts to disperse roots into the new home soil immediately as it emerges from dormancy in late winter. Without cans, bare root stock can not get root bound. Instead of developing branch structure that is appealing to nursery marketing, bare root stock can get an early start on developing branch structure that is most practical and efficient for the gardens that it gets installed into.

It seems that all of the ´stone’ fruit can be found as bare root stock. These include apricot, cherry, plum, prune, peach, nectarine, almond (which is the seed, or ´stone’, of a peach like fruit) and the odd hybrids of these. The pomme fruits, apple, pear and quince, are perhaps the second most popular of bare root stock, although quince is still rather rare. Ornamental trees, shrubs and vines include flowering crabapple, flowering cherry, flowering quince, alder, poplar, willow, lilac, forsythia, wisteria and clematis. Perennials include rhubarb and artichoke.

Bare root stock can be purchased as soon as it becomes available, but does not do much until it starts to grow in spring. It should get planted quickly and soaked in, but will get more water than it needs from rain afterward. It should not need water again until after it blooms or gets new leaves in late winter or early spring. Despite guarantees of fruit in the first year, none should be expected. The few fruit trees that might set fruit will probably produce only useless underdeveloped fruit because new plants are busy producing new roots and growing. Actually though, this apples to canned stock as well, except only for citrus, olives and other evergreen fruit trees.

Chanterelles?

Are these chanterelles? I found them at the base of a dead and rotting coast live oak on the Upper East Side. I took their picture because friends had been asking me if there are any chanterelles to collect there. Apparently, chanterelles can be sold for quite a sum to restaurants. I really should have been more observant when I took these pictures, to see how many more of the same, if any, were in the area. I will not return to the area anytime soon, unless I need to show someone else where it is. It is quite a hike to get there, with a very steep incline. It is likely too late to collect chanterelles anyway. They supposedly emerge after the first autumn rain, but finish through November, which is likely why these look so deteriorated and dried. However, locally, they can continue to appear throughout winter if weather conditions are favorable. I am certainly no expert. After all, even if these are chanterelles, this is my first experience with them. We are barely acquainted. I do not trust them enough to taste them. Nonetheless, I would be pleased if friends could collect real chanterelles for a profit.