Toxic Plants In Home Gardens

Even toxic plants have their attributes.

Oleander that inhabits freeway medians is poisonous enough to be hazardous. Two tons of Buick cruising at sixty-five miles per hour past such oleander has more potential to be hazardous. The risk associated with toxic plants within freeway medians is as limited as their accessibility. Remarkably durable and resilient oleander is therefore quite practical.

Realistically, established oleander is quite practical for many landscapes. (Oleander leaf scorch limits the practicality of new installation though.) It is not the sort of vegetation that is appealing for consumption. Caustic sap should deter anyone who tries. It is poisonous primarily to curious young children or chewing dogs. It is generally safe in their absence.

Foxglove, angel’s trumpet, castor bean, nightshade and poison hemlock are significantly more hazardous because they are easier to consume. The seeds of castor bean and the fruits of nightshade actually seem to be edible. Poison hemlock sometimes mingles with foraged greens. Many diverse toxic plants exhibit hazardously appealing characteristics.

Some toxic plants are appealing enough to come indoors, where cats who never venture outdoors might take an interest in them. Dumb cane (Dieffenbachia) is a popular but very toxic houseplant. Mistletoe, although a parasitic and undesirable weed, is popular as cut foliage at Christmas. Its berries are very toxic. Poinsettia exudes caustic sap if disturbed.

Some toxic plants are toxic only because they are allergens. They affect only those who are allergic to them. Most people are allergic to poison oak. Fewer are allergic to related plants, such as African sumac. Some people are more or less allergic to a few species of Grevillea or Primula. Reaction to such species can be comparable to that of poison oak.

Too many toxic plants inhabit home gardens to list. Some are familiar fruit and vegetable plants, such as elderberry and potato. Some should be removed for the safety of children or pets. Selection of new plants can simply and conveniently omit any concerningly toxic plants. Generally though, with responsible interaction, most toxic plants are not too risky.

Good Neighbors Make Good Fences

Is privacy really worth big fences?

Good old fashioned suburbia will never bee the same. Bigger modern homes on smaller modern parcels leave little space for gardening and trees. What is not shaded by the taller homes is shaded by the taller fences, which are ‘needed’ for privacy since the homes are closer together. Building codes in most municipalities limit the height of fences, but lattice screens are often added on top for extra height.

Because lumber is not of the quality that it was when shorter light duty redwood fences were built decades ago, relatively expensive modern fences do not last nearly as long. They might last longer if they would get repaired instead of replaced when only the posts rot. Green technology seemed to work better before it became trendy.

Ironically, no one wants these bigger and bolder fences that are closer to home to be so prominent in the landscape. We try to obscure them with vines that can tear them apart, or shrubbery that can push them over. Watering these vines and shrubs accelerates rot in the posts.

Shrubbery intended to obscure a fence should not be so voracious that it wants to displace the same fence that it is intended to obscure. Some types of pittosporum work nicely because they support themselves without leaning against other features in their surroundings too much, even if they eventually get quite large. However, they do get quite thick, and can obscure a fence so well that no one would miss the fence if it were to get pushed over! A good hedge without a fence is sometimes a better option.

Many types of vines can be kept much closer to a fence than shrubbery can, but most tend to be more destructive. Star jasmine works nicely if allowed to climb a trellis directly in front of the fence, but should not be allowed to get between planks in the fence, or to get too intertwined in lattice. If it gets too fluffy, it can be shorn back like a light hedge.

Clinging vines like creeping fig can be very appealing on fences, and can be shorn like hedges, but will eventually necessitate the replacement of the fences that they climb. For those who appreciate such a tailored appearance, replacement of the affected fences every few years is a fair compromise.

Perennial Plants Keep On Giving

Can a canna be too perennial?

Many popular annual bedding plants have potential to be perennial if they get a chance. Cyclamen commonly perform as a cool season annual, only until replacement with warm season annuals. However, after summer dormancy, their tubers can generate foliage and bloom again for several following winters. Replacement is just easier than maintenance.

Real annuals complete their entire life cycles, from germination to dispersal of seed and finally death, within a single year. Biennials generate vegetative growth through their first year, and then disperse seed and die during their second year. Perennials perform for at least two years, whether or not they get any opportunities to do so within home gardens.

Home garden culture complicates this classification though. Those who enjoy gardening expect perennial plants to reliably perform for many years or indefinitely. Many perennial plants do so with only minimal intervention. Some are self-sustaining, and might seem to naturalize. That may be why so many smaller or less vigorous types classify as annuals.

Another qualification of perennial plants is that they lack woody stems and roots. In other words, they are herbaceous. Palms and species of Yucca that develop trunks classify as perennial plants also, but for simplicity, the larger types are herbaceous trees. Generally, perennials are terrestrial. A few are epiphytic (live in trees) or lithophytic (live on stones).

Although several perennial plants can survive indefinitely here without intervention, most perform better with some degree of attention. Most ferns are neater if groomed to remove deteriorated fronds. Many grasses benefit from severe shearing during winter. African iris blooms better in response to regular deadheading to remove developing seed capsules.

Perennial plants are very diverse. It is impossible to generalize about their maintenance. One commonality among many is that they multiply. Lily of the Nile can produce so many individual shoots that it can eventually become too congested to bloom. Division of such shoots every several years or so promotes bloom, as well as propagates more plants for elsewhere in the landscape.

Some Plants Can Go To Pot.

What ever happened to those poinsettias and cyclamen from last Christmas?

Chrysanthemums, hydrangeas, azaleas, callas, kalanchoes and miniature roses can not really be as happy as they seem to be while in full bloom at the florist counter. Then there are all the seasonal blooming plants like Easter lilies and poinsettias. Wrapped in undraining mylar, often with ribbons and bows, they are actually quite humiliated.

All are forced to bloom in artificial greenhouse environments that are nothing like the home environments that they ultimately go to. As they finish bloom, most get retired directly to the garden where many are unable to adapt quickly and efficiently enough to survive for long. Many do not make it that far, but get sent to the compost or the trash by those who prefer to not prolong their agony.

These potted plants (which are actually known as ‘pot plants’ in the horticultural industries) are not like houseplants, since they are not actually expected to survive for long in the home. They are only expected to perform for a limited time while in bloom.

Adapting to the home environment is not the difficult part. Most potted plants can manage that for a while, but eventually want more sunlight. Hydrangeas, roses, Easter lilies and other deciduous plants also eventually want a cool winter for their dormancy. The problem is adapting to exposure to the sunlight and weather that these plants crave. Foliage can get scorched, frozen or desiccated.

As unsightly as plants can be during transition, most can eventually replace their greenhouse foliage with foliage that is adapted to their new environment in the garden if transitioned slowly and carefully. Large ‘forced’ flowers will eventually be shed or can be pruned off as they deteriorate. The more sensitive types of plants should be moved to a sheltered spot on a porch or in partial shade for a few months before being moved to more exposed spots. Once in the garden, they will want regular watering until their roots disperse.

Deciduous plants and bulbs can stay in the sheltered spot until they defoliate for winter. If put into their permanent location while dormant and bare, their new foliage that emerges in spring will be adapted to the new exposure.

Aloes, Christmas cactus and various other succulents are considerably more resilient and adaptable than the more common potted plants. Both rosemary and small olive trees that have become trendy during the past many years can likewise be adaptable if not kept in the home too long. Olive trees can stay potted indefinitely if pruned regularly, or can go into the garden where there is room to grow. Christmas trees are just as adaptable, but do not want to stay potted for long. Sadly though, most get much too big for home gardens.

Dog Days Of Summer Warmth

Every lawn has its dog days.

Summer began more than a week ago. Subsequently, the dog days of summer continue from the third of July to the eleventh of August. These forty dog days are the twenty days prior to and after the twenty-third of July. That is when the Sun aligns with Sirius, the Dog Star of the constellation of Canis Major, or ‘the Great Dog’. Dogs are actually uninvolved.

Nonetheless, dog days actually are a time for dogs to languish through much of the most unpleasantly warm weather of summer. Although local climates are generally mild, warm weather is not rare. It merely seems to be less oppressive than in other climates because of less humidity, and perhaps more of a breeze. Coastal influence is a major advantage.

Dogs drink more water during the dog days of summer because they lose moisture, with warmth, while panting. Vegetation also needs more than typical quantities of moisture to compensate for increasing evaporation from foliar surfaces. Aridity and any wind, both of which render warmth more comfortable for dogs and people, increase such evaporation.

Also, for most exotic (nonnative) vegetation, regular watering helps to sustain growth that warmth stimulates. Lily of the Nile can likely get enough moisture through the local rainy season to survive through the dry season. However, it is healthier and more appealing if occasionally watered to sustain its most vigorous growth during the dog days of summer.

Many plants are native to climates that supply rain in conjunction with warmth. They rely on moisture for normal growth. Various bananas, canna, angel’s trumpet and giant bird of Paradise grow very vigorously with sufficient moisture. Unfortunately though, insufficient moisture is very distressing to them. Drought tolerant species have a distinct advantage.

Turf, bedding plants and vegetable gardens need abundant water during the dog days of summer. Although some can survive with less than others, none are exempt. Most potted plants, especially those in hanging pots, are likewise dependent on systematic watering. Even if the weather is too warm to enjoy other gardening, watering can not be neglected.

Color Outside The Spectral Lines

Infrared and ultraviolet are humanly invisible.

Green is the most common floral color. It only seems to be rare amongst flowers because almost all green bloom relies on wind for pollination. Thus, neither color nor fragrance is useful to get the attention of pollinators. Actually, green flowers do not get much attention at all. They are easy to ignore in the wild, and generally unpopular within home gardens.

Most showy green flowers such as zinnia, chrysanthemum, hydrangea and gladiolus are progeny of unnatural breeding. Showy but naturally green flowers such as hellebore and orchid are merely incidentally green, as they employ infrared or ultraviolet color to attract pollinators. Although people can not see infrared or ultraviolet color, many pollinators do.

After all, flowers bloom only for pollination. Many customize color as well as fragrance to appeal to preferred pollinators. They are merely incidentally appealing to people as well. People breed flowers to be more appealing to people, even if unappealing to pollinators. Nonetheless, even breeding is limited to characteristics that initially attracted pollinators.

It is impossible to identify the most common color among flowers that rely on pollinators. Pollinators are regional. Therefore, red and orange flowers may be more common where hummingbirds who prefer red or orange are more common. Purple flowers may be more common where bees or certain butterflies who prefer purple are the dominant pollinators.

Yellow seems to be the most common natural color of flowers of North America. Red and orange are very common as well. Although common, pink is merely a tint of red, so is not a real color. Neither is brown, which is a shade of orange. Although very common among flowers that rely on wind pollination, it is quite rare among flowers that rely on pollinators.

Blue is the rarest natural floral color. Many flowers that seem to be quite blue are actually purplish. Purple is uncommon, but not as rare as blue. Ultraviolet and infrared get almost no consideration since they are invisible to people. However, both are common amongst most showy flowers, particularly white and maybe red flowers. Red is invisible to insects, though infrared is not.

Arid Climates Can Be Challenging

Some plants shrivel in arid warmth.

‘Mediterranean’ translates as an adjective that describes being at the middle of the Earth. Those who inhabited that region many centuries ago considered the Mediterranean Sea to be central to their World. That was long ago and far away. Nonetheless, climates here and now are somehow Mediterranean. Maybe semi arid climates of Italy are Californian.

Mediterranean climates are temperately warm with dry weather through summer. Rain is almost exclusive to a rainy season between autumn and spring. Although rain can briefly get abundant during the rainy season, the average annual rainfall is modest. Humidity is minimal for much of the time. Arid warmth is more comfortable than rarely humid warmth.

Desert climates accumulate less than ten inches of rain annually. Local climates receive more than fifteen inches of rain annually. They are therefore not sufficiently arid to qualify as desert climates. Technically, they are only semi arid chaparral climates. This climactic designation is perhaps more appropriate than the regional designation of Mediterranean.

Native plants and plants that are native to other chaparral climates are naturally pleased with the local climate. However, some initiate at least partial dormancy to survive through the long and arid summers. They may bloom early, but then partially defoliate for several months. Some delay dormancy if watered. A few dislike watering. It is unnatural for them.

Most plants in home gardens are not native to chaparral climates. They require watering to compensate for aridity during summer. Minimal humidity accelerates evaporation from foliar surfaces, which increases the demand for moisture. In conjunction with warmth and wind, aridity can desiccate foliage. Like people and pets, plants must maintain hydration.

Humid warmth that is less comfortable for people and pets is more comfortable for plants than arid warmth is. Humidity inhibits evaporation from foliar surfaces so plants consume less moisture. Incidentally, most pathogens, such as fungal diseases, bacterial diseases and most insects, also prefer warm humidity. People and pets seem to be in the minority.

Drought Tolerance Necessitates Root Dispersion

Extensive root dispersion enhances drought tolerance.

Fads certainly complicate gardening. Most are merely marketing tactics. Most are bogus. Many even contradict their justifications! For example, most new, trendy and supposedly sustainable plant cultivars are genetically weak because of extensive breeding. Drought tolerance likewise has potential to be a constructive fad, but is so commonly misapplied.

Incidentally, its terminology is somewhat inaccurate. Drought is an extended but unusual pattern of dry weather. Whether the duration is for one year, or many, it is not permanent. The dry weather that persists through summer locally is normal for the chaparral climate. It is therefore a normal characteristic of climate, rather than abnormal weather conditions.

Drought tolerance is therefore practical here as chaparral tolerance. Most plants that are drought tolerant are naturally endemic to chaparral regions or deserts. Many of the native species naturally exhibit remarkable drought tolerance. Once established, they might not require any more moisture than they get from annual rainfall. Some prefer dry conditions.

Drought tolerance should not imply that such plants are undemanding. In some regards, they are more demanding and less adaptable than plants that require frequent watering. Such plants rely on extensive root dispersion to procure the moisture they require within dry situations. Most do not adapt to confinement, even if watering is enough to cause rot.

Container gardening is therefore a fad that is incompatible with drought tolerance. It only uses less water for plants that use more water. Also, modern drip irrigation, which is very practical for plants that rely on irrigation, requires a bit more effort for plants that use less moisture. To not promote rot, emitters must move farther from main trunks as plants grow.

Many of the most sustainable and drought plants are old fashioned sorts that became too common years ago. Fortunately, some are regaining popularity again. Some of the more compact eucalypti are proportionate to modern gardens. Grevillea, bottlebrush, rockrose, juniper, rosemary, salvia, lavender and New Zealand flax are as drought tolerant as they had always been.

Foliar Color Goes Beyond Green

Foliar color can exceed floral color.

New England is famous for spectacular foliar color through autumn. Such color is merely seasonal though, and almost exclusive to deciduous vegetation. With few exceptions, its color range is limited to variations of yellow, orange, red or brown. It happens thousands of miles away, and is difficult to replicate on such a grand scale with locally minimal chill.

For smaller scale home gardens, there are many options for foliar color at any time of the year, regardless of chill. Some are deciduous. Most are evergreen. Colorful foliage might exhibit variegation or monochromatic coloration. Variegation might involve stripes, spots, borders, veining, or any combination of divergent colors. Some might entail a few colors.

Besides autumnal yellow, orange, red or brown, foliage can be pink, purple, blue or gray. Variegation can feature any of these colors, as well as white. The size and form of plants with foliar color ranges from small annuals and perennials to vines, shrubbery and trees. A few of such plants that are deciduous might change to different colors through autumn.

Various Hosta, Euonymus, Coprosma, Pittosporum, Hedera and Bougainvillea are some of the more popular plants with white or yellow variegation. New Zealand flax is popular for bronze, brown, gold or pink variegation. Canna can display evenly bronze or purplish foliage, white patches on green foliage, or neat yellow and pink stripes of varying widths.

Purple leaf plum and some cultivars of smoke tree, beech Eastern redbud and Japanese maple have the best purplish foliage. Other cultivars of smoke tree, as well as arborvitae, juniper, Monterey cypress and honeylocust, generate impressively yellow foliage. Agave and blue spruce contribute soft blue. Coleus impresses with various color combinations.

Whether deciduous or evergreen, most colorful foliage displays its best color while fresh and new in spring. For some, color fades through summer. Junipers that are gold through spring may be plain green by summer, particularly in dry conditions. Although light colors and variegation are appealing within shady situations, shade can inhibit such coloration.

Simplicity Is Best For Parkstrips

Clumping grasses hang out over curbs.

Parkstrips, those narrow spaces between curbs and sidewalks, are among the most awkward spaces in the garden. In urban areas with significant traffic, they are commonly paved over. Some neighborhoods, especially downtown neighborhoods, do not have parkstrips at all. Suburban neighborhoods though, often have wider parkstrips.

The difficulty with parkstrips is that there is so much happening around them. Cars get parked on one side. Pedestrians pass by on the other side. Driveways need to be kept clear at each end. Water meters and perhaps other subterranean utilities must be accessible.

Street trees are common features in parkstrips. They should have complaisant roots that will be less likely to displace the surrounding pavement and curbs, and high branch structure for adequate clearance above truck traffic on the roadways below. Ideally, street trees should conform with the neighborhood, and are often quite uniform. Selection of street trees should be a community effort where practical.

All other plants that go into parkstrips should be adaptable to confinement within the limited space available. They should not extend over curbs or sidewalks where they can scratch parking cars or be obtrusive to pedestrians. Parkstrip landscapes must also stay low enough so that they do not obstruct the view from cars backing out of driveways.

Because people regularly walk past or through parkstrips, thorny plants like cacti and roses should be kept back from the edges, or preferable not put into parkstrips at all. Large agaves and yuccas (with rigid leaves) are simply too big and dangerous for narrow parkstrips.

Contrary to the trend of planting vegetables in weird places, parkstrips are not good places for them either. The main problem is what dogs like to do in parkstrips. The second problem is that the good produce that might be out reach of dogs is within reach of everyone else walking or driving by. Reflected glare from all the surrounding pavement is a problem for plants that do not like harsh exposure.

Really, there are far more limitations on parkstrip landscaping than there are options. Turf grasses or tough ground cover that tolerates traffic, like trailing gazania, may seem to be a mundane, but they are practical. At least ground cover can be punctuated with clumping perennials like African iris, lily-of-the-Nile or blanket flower.

Pots are overrated, especially for curbsides.