Ferns Are Made For Shade

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Ferns are famous for distinctive foliage.

Without color or fragrance of flowers, ferns provide some of the most distinctive foliage in the garden. They do not turn color in autumn. Only a few tree ferns develop sculptural branch structure. Yet, they do their job well, and many are happy to do so in spots that are a bit too shady for other plants.

Almost all ferns are low perennials that produce foliage that arches outward from the center. Some can get quite broad. A few tree ferns grow upward on trunks (although the trunks are merely tough roots that grow through decomposing stems). Australian tree ferns can get quite tall and broad where sheltered from wind.

The staghorn fern is a weird epiphyte that naturally clings to tree trunks or rock outcroppings where it collects organic debris that falls from trees above. In home gardens, it is popularly grown on wooden plaques or as a hanging plant. Hanging plants do not necessarily need pots, or sometimes engulf their pots as they grow.

Leaves of ferns are known as ‘fronds’, and with few exceptions, are intricately lobed or divided into smaller leaflets known as ‘pinnae’, which are arranged on opposite sides of leafstalks known as ‘rachi’ (or singularly as ‘rachis’). The staghorn fern has unusually branched but otherwise unlobed fronds. The bird’s next fern has has distinctively simple fronds without any lobes or pinnae.

Most of the popular ferns are naturally understory plants that grow below larger plants. Even most tree ferns grow amongst larger trees. This is why so many ferns tolerate shade so well. In fact, many prefer partial shade, and will actually fade or scorch if too exposed. However, it is also why so many ferns prefer rich soil with an abundance of organic matter.

Maidenhair, rabbit’s foot, bird’s nest, holly, Boston and a few other ferns are popular as houseplants. Because home interiors are a somewhat arid for them (lacking humidity), some ferns like to be misted daily. Ferns respond well to regular but light application of fertilizer. Too much fertilizer can roast foliage.

Because ferns are not expected to bloom, nitrogen (which can inhibit bloom for some plants) is not a problem. Ferns that are out in the garden can therefore get fish emulsion or a bit of the same sort of nitrogen fertilizers that keep lawns green.

Foliage Is Meant For Weather

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Lush foliar houseplants enjoy occasional rinsing.

Foliage needs sunlight for photosynthesis. Foliage needs air for respiration. Roots need moisture to sustain foliage. Houseplants can technically get all of what they need from the confinement of their pots within the interiors of homes and other buildings. They only require sufficient moisture to be delivered to them, and sufficient sunlight from windows. The air is the same that we all utilize.

However, there is no substitute for nature. While hydroponics and synthetic light facilitate yet more deprivation of what is natural, the plants involved would appreciate more consideration. Without exception, domesticated plants are descendants of plants that grew wild somewhere. Those that dislike local weather would be pleased with the weather of their respective ancestral homelands.

Most of the popular houseplants that are grown for their lush foliage originated from tropical forests. Many were understory plants that prefer the shade of larger trees. That is how they tolerate the relatively shaded interiors of buildings. Now that they are here as houseplants, they appreciate shelter from frost. They probably miss rain, humidity, sporadic breezes and tropical warmth though.

Rinsing tropical foliage plants in the shower eliminates some of the dust that they accumulate where air stagnates. Rinsing them out in the garden is even better because it does not make such a mess in the shower. What is even better than both of these options is allowing a gentle rain to rinse the foliage. Plants only need to be moved to a windless spot prior to an expected rain shower.

The weather was much too cool earlier in winter. There will be no rain later in summer. This time of year, and again next autumn, the weather is safely mild; and eventually, a few showers are likely. Timing is critical. Plants should be brought out just prior to rain, and brought in before the weather gets sunny. Foliage that has always been sheltered is very sensitive to scald from direct sunlight.

Saucers and pots can be cleaned while outside. Crowded plant can be repotted.

Evergreens From Our Home Gardens

91225thumbEvergreens are popular for home d├ęcor through winter because there is not much blooming so late in most other American climates. The tradition endures, even though cut flowers of all sorts can easily be purchased from common supermarkets nowadays. Here on the West Coast, where several varieties of flowers can bloom through winter, evergreen foliage is as popular as it ever was.

Christmas trees are the most substantial form of traditional seasonal evergreens. The biggest wreaths occupy less space, and are mostly confined to walls rather than floors. Garlands can be big too, but their less defined form fits more neatly into limited space. For many of us, neatness is not a priority. Displays of evergreens and all the associated ornamentation can get quite elaborate.

Not many of us grow our own Christmas trees. It is more practical to purchase them as if they are very large cut flowers. Most but not all of us who hang garland likewise procure it already made. Some purchase prefabricated wreathes too. However, it is possible that more of us create our own. Other bits and pieces of evergreens are unlikely purchased. Most are from our home gardens.

Most of the pine, spruce, fir, hemlock, yew, arborvitae, and various genera known collectively as cedar, that are traditional evergreens in other regions are scarce here. A few other exotic species of pine, as well as natives, are more common in some landscapes. There are also different cedar and arborvitae. Blue spruce can sometimes be found. Douglas fir is native to nearby mountains.

Other regions lack the abundance of various cypress and juniper that are common here, as well as coastal redwood. (Redwood foliage is perishable once cut.)

There are no rules about cut evergreens anyway. Within reason, we can cut and bring in whatever we happen to find to be appealing in our gardens. We should cut the foliage properly though, as if pruning. Also, we should not cut too much from any particular spot, but instead harvest evenly over a large area. It helps to take pieces that are out of view, or that need to be pruned out anyway.

Deck the Halls

P91215-1English holly is politely naturalized here. This means that, although naturalized, it is not aggressively invasive, and does not seem to be too detrimental to the ecosystem. It is only annoying to see out in forests, far from the landscapes that the seed escaped from, and wonder if it has potential to significantly compete with native vegetation. It would be better if it were not there.

At least it is pretty. In refined landscapes, it happens to be one of my favorites for distinctively glossy and prickly foliage. There is nothing else like it. Variegated cultivars are just as striking, with a bit of color for situations where there is already plenty of rich dark green. Female plants produce a few bright red berries. Older or distressed plants might produce more than others.

So, I have mixed feelings about this overgrown English holly tree that I must eventually cut down. In the picture above, it is evident that it is not the prettiest. It is a sparsely foliated thicket of tangled inner stems on an uninterestingly straight and bare trunk. It occupies a prominent position where there should be something of a friendlier disposition. It doesn’t contribute much.

However, it does produce an abundance of delightfully bright red berries. I got these pictures while collecting berries to decorate the buffets and tables of the big dining room across the road.

If it were in my garden, I would probably pollard it back to the bare trunk or perhaps just a short stump, and allow it to regenerate with fresh new foliage. Such a procedure would eliminate the tangled thicket of bare interior stems, but would unfortunately inhibit berry production for at least a few years while new growth matures. I just do not want to give up on it completely.P91215-2P91215-3

Autumn Weather Prompts Foliar Color

91127thumb(alternate)Mild climates allow more flowers to bloom through autumn and winter here than in most other parts of America. That is why cool season annuals like pansies and violas are so popular. Cyclamen can be planted now too. None will be obscured by snow. By the time cool season annuals start to fade, warm season annuals will be replacing them. There is something to bloom in every season.

There are a few disadvantages to mild climates, though. Many plants rely on significant winter chill to stay on schedule. Inadequate chill limits the cultivars of apples and pears that are productive here. Not many spring bulbs will naturalize. Prior to winter, some deciduous plants are hesitant to resign to dormancy until they experience a chill that is cool enough to convince them it is autumn.

Some deciduous plants recognize a specific temperature as credible evidence of a change of seasons. Others want a specific temperature to be sustained for a specific duration or repeated for a few nights. Shorter days and longer nights are taken into consideration by species who want to confirm what they deduce from the weather. Different plants use different methods of observation.

That is why deciduous plants who develop foliar color before defoliating in autumn do so on their own terms. Weather conditions that promote excellent color among birches may not be the same that cause flowering cherries to color well. Warmth and minimal humidity that sometimes prompt premature and blandly colored defoliation of sycamores might enhance later color of sweetgums.

Sweetgum, Chinese pistache, flowering pear and ginkgo are the most reliable trees for foliar color in autumn. Ginkgo turns only brilliant yellow. The others exhibit an excellent mix of yellow, orange and red. Crape myrtle can be about as colorful, but is not always as reliable.

Of course, there is more to these and other deciduous trees than their colorful foliage in autumn. After all, they are trees. Their particular characteristics and appropriateness must be considered before adding any of them to a landscape.91127thumb

Slow Color

P91110Autumn is not much to brag about here. It supposedly got just cool enough at night for the minimal requirement of frost, at 32 degrees, but no one noticed. It has been getting to the low 80s during the day. There has been no rain yet, and none is in the forecast. As bland as such weather seems, it is not at all out of the ordinary. Autumn often arrives later than it does elsewhere.

Consequently, autumn foliar color is not much to brag about either. There are only a few trees that reliably develop good color, such as sweetgum, pistache, flowering pear, crape myrtle and maidenhair tree (ginkgo). As reliable as it is, maidenhair tree provides only bright yellow, without the oranges and reds that the others exhibit. None are exhibiting significant color just yet.

There are several other trees that have potential to develop good color, but are not as reliable about doing so. Birch can get almost as brilliant yellow as maidenhair tree does, but does not do it every year. Red oak may turn brilliant orange with a bit of brownish red mixed in, but only every few years or so. On rare occasion, even London plane (sycamore) shows off burnt orange.

Every species has a distinct personality. They each respond differently to different variables. Weather conditions that stimulate good color among flowering cherries may not stimulate good color for bigleaf maples. Dogwoods that colored so well at about the same time last year as the tulip trees, are already nearly bare after minimal color, while the tulip trees are mostly green.

Every few years, if mildly but suddenly chilled, these cottonwood develop a brighter yellow, with less blotching. With slower and drier chill this year, they are deteriorating and falling without much yellow at all.P91110+

Dyckia

91023It is easy to mistake various cultivars of Dyckia for diminutive relatives of Agave or Yucca. They form stout rosettes of rigid leaves with wickedly sharp terminal spines. Their comparably nasty but incurved marginal teeth resemble those of most species of Agave, but are generally more abundant. Surprisingly though, Dyckia are instead related to bromeliads. They just happen to be xeric.

Dyckia do not bloom much, but when they do, the tall and arching floral stalks really are more typical of bromeliads. As they bloom late in spring or in summer, the many small individual flowers on each stalk are collectively colorful enough to be delightfully popular with hummingbirds, butterflies and bees. Bloom is most commonly rich reddish orange, but some cultivars bloom red or yellow.

No one seems to mind that Dyckia does not often bloom. The foliage is remarkably striking alone. Many cultivars form dense mounding colonies of pups that, although unpleasant to handle, can be divided for propagation. A few toothless cultivars, armed only with terminal spines, are easier to handle. Individual rosettes can be as tall and broad as a foot. Dyckia do not need much water.

Hedges – Living In The Background

90918thumbPretty soon, as autumn weather starts to get cooler, some deciduous plants will develop brilliant color before defoliating for their winter dormancy. Throughout the rest of the year, evergreen plants with gold, silver, bronze, bluish, purplish, reddish or variegated foliage are more colorful than common green foliage is. A few deciduous plants with colored foliage turn different colors in autumn.

Such colorful foliage is generally appealing in the garden. However, there are reasons why not all plants in the garden are so colorful. There really is the potential for too much of a good thing. If all foliage was always colorful, landscapes would look cluttered. Flowers would not be so prominent. There are many situations for which plain and simple evergreen foliage is likely the best choice.

That is why simple evergreen hedges of the various species and cultivars of pittosporum, privet, holly, arborvitae and laurel are still so popular. Some are formally shorn. Where space is sufficient, others are informal screens in which the shrubbery is more or less allowed to assume its natural form and size. The various boxwoods are useful for smaller evergreen and formally shorn hedges.

Most contiguous hedges and screens are intended to separate spaces or obscure fences or buildings. Some sporadic sorts might only expected to disrupt the expansiveness of large buildings or partially deflect prevalent breezes. What they have in common, is that they are in the background. Some are behind or next to lawns, patios or decks. Others are behind more prominent plants.

Shearing hedges that are adjacent to lawns, patios and decks is of course much easier than shearing those that are behind other plants. Screens or hedges behind rose gardens, dahlias, flower beds, or anything that might be damaged by the process of shearing a hedge, should be of the sort that do not need to be shorn regularly. Nor should they be so colorful that they steal the show.

If possible, maintenance of hedges should be scheduled to coincide with the off season of plants in their foreground.

Delta Maidenhair Fern

90904Some of us might remember Delta maidenhair fern, Adiantum raddianum, as a houseplant that was popular for terrariums in the 1970s and into the 1980s. Although quite happy in terrariums, it eventually gets big enough to crowd other plants in such tight spaces. It prefers to be potted on a porch, or in a regularly watered and sheltered spot in the garden. It tolerates quite a bit of shade.

Regular watering is important to keeping the foliage well hydrated, particularly among potted plants that are unable to disperse their roots into surrounding soil. The stolons bellow the foliage are not so sensitive, so can regenerate new foliage if partly desiccated old foliage needs to be cut back. They want good rich soil or potting media, and appreciate occasional application of fertilizer.

Individual fronds (leaves) have the potential to get as long as a foot, and half as wide, although they are mostly significantly smaller, and might be only half as long. Each frond is intricately divided into many small leaflets that are almost triangular, except that their out edges are curved and scalloped. Foliage is lighter green than that of most other ferns. Rachi (leafstalks) are black and thin.

Ferns Are Delightful Without Bloom

90904thumbMany of the most popular plants are expected to bloom to add color and fragrance to the garden. Many others are grown to produce fruit or vegetables. Some are appreciated for their foliar color in autumn. Big trees are grown for shade. Turf grasses are grown as lawn. Evergreen shrubbery makes hedges. It seems that all plants perform particular tasks in the gardens which they inhabit.

Ferns only need to provide rich foliage. They do so very efficiently, with remarkably stylish and distinctive textures, and deep green color. Most ferns are evergreen, so only need to be groomed of their old foliage as it gets replaced by new foliage. Most of the few deciduous ferns are bare only briefly during their respective dormant seasons. Some can grow wild without any grooming at all.

Many ferns are famously tolerant of partial shade that is too dark for many other types of plants. Many are tolerant of confinement, so are happy in pots, planters and small atriums, or under stairs. Some ferns that are tolerant of both shade and confinement are popular as houseplants. Those that get too big or their situations are generally easy to dig and relocate, or divide into more plants.

There are only two species of tree fern that are common here; the Australian tree fern, and the New Zealand tree fern. Australian tree fern is taller with leaner trunks. Tasmanian tree fern is short and stout. These and more rare tree ferns are the only ferns that leave the ground as they develop ‘trunks’ of tightly bundled fibrous roots dispersed through the decayed remains of their rhizomes.

Their rhizomes are just their thick herbaceous stems. Those of tree ferns do not branch into more than a single terminal bud, so can not be divided. Rhizomes of most other ferns split into clumps of a few or many individual budded rhizomes, which can be divided if they get too crowded. Leaves that grow from the rhizomes are known as fronds. The fronds of almost all ferns are divided into smaller leaflets known as pinnae, which are suspended by leafstalks known as rachi.