Container Gardening – Can Your Balcony Take The Weight?

Growing plants in pots and planters can add considerable stress, weight-wise, to your balcony or roof. It may seem an obvious consideration, but judging by what is common in many homes, it is clear that many people are simply unaware that their roof or balcony garden has exceeded the weight limit that the building codes stipulate for any given situation. It may be worth considering the consequences, both legal and otherwise, in the event of an accident.

It would be advisable therefore, to invite a building engineer to check your balcony. Meanwhile, here is a typical example. A balcony may have a weight limit of 150 kilograms per square meter. The volume of a very large pot containing a tree that reaches some 4 meters in height, could have a volume that is about 150 liters. As one liter of water weighs one kilogram, it follows that the weight of the pot filled with water, would reach 150 kilograms. This is without potting soil, and the weight of the tree. I have often seen the weight limit exceeded four or five times over! Here then are some guidelines to keep you on track.

The Container

Firstly, choose lightweight containers. Plastic is obviously the lightest material, although you may dislike, as I do, the very idea of mock terracotta pots. However, there are many plastic products available today that are highly aesthetic. The rule is to avoid products that are pretending to be something they are not, such as some fake ceramic container.

The size of the pot is the next consideration. To keep the weight down, you have to limit the dimensions of the container. This means that it is virtually impossible to grow plants beyond a height of 2-2.5 meters, (6-8 ft) because taller plants, require a deeper pot to prevent them toppling over in the wind. The deeper the pot of course, the greater the weight exerted on the floor.

The Potting Mixture

There are excellent horticultural reasons for growing container plants in an artificial potting medium as opposed to garden soil. However, just in case you were thinking of ignoring these, just think of the weight factor, as the weight of soil, especially clay soil, expands exponentially when saturated with water. From every point of view therefore, garden soil should never be used in containers grown on the roof or balcony. The question is which type of potting medium is the most suitable, at least from the weight angle? Unquestionably, the media such as “Perlite”, which are both extremely light, yet retain sufficient moisture, are to be preferred to the usual potting mixtures, whose weight also increases significantly, when wet.

Pruning Flowering Shrubs And Bushes – Some Essential tips for Success

The role of most landscape shrubs and bushes is to serve as a screen or backdrop. Some species while primarily acting as such, also add color to the garden with their flowers, foliage or decorative fruit, although this should not be at the expense of their landscaping role. A clear distinction should be made between them and shrubs such as roses that are specifically grown for their flower color. In the case of the former, (the essentially landscaping bushes) the aim of pruning is to maintain a compact, dense growth habit, without entirely eliminating the flower buds in the process. With heavy-duty flowering shrubs however, pruning is designed simply to increase the number and quality of the blooms.

Plants that are left unpruned produce flowers at the tips of old stems. Pruning the plant down by a third or a half of its height however, creates young, vital tissue. The flowers that emerge from them are likely, as previously mentioned to be both more numerous and of superior quality. Another reason for annual pruning is to ensure that the flowers appear more or less at eye level and not up in the sky!

A crucial question for the gardener is whether the plant blooms on the current year’s growth, or on that of the previous year. Most flower on juvenile growth that originated during the spring of the current year. Whether the plant is pruned in the winter as with deciduous species, or in the spring, as is the case with evergreen and non-hardy plants, the annual prune may delay the appearance of the flowers, but it should dramatically improve the blooming nonetheless.

Some plants however, including a number of wild roses, flower on tissue that originated in the spring of the previous year. This means that winter or spring pruning, i.e. pruning that is carried out prior to the emergence of the flowers, will only succeed in removing the flower buds from the plant’s stems. It is not uncommon to hear a home gardener say with some frustration; “my Lilac bush is very lovely. It never seems to flower though” Small wonder!

Therefore, the rule with such plants is to prune them after they have finished flowering, unless they produce decorative or edible fruit. However many species, especially roses, suffer from a heavy prune that is carried out in the middle of their growing season. The answer is to remove the spent flowers, (deadheading) without resorting to a serious, structural prune. If the plant really needs such treatment, then it is best to wait for the appropriate season, and give up on the flowers for one year.

Regular, serious pruning takes its toll on the energy level and general health of any plant, including shrubs and bushes. One cannot afford to ignore the other requirements of the plant, particularly those relating to soil aeration, moisture levels, and feeding. Plants like roses, which are grown for their flower color, and as a result, are subjected to intensive horticultural practices (i.e. pruning) have a limited life span – perhaps 10-15 years of worthwhile performance. Landscaping shrubs, including those that flower, should be seen as a more long-term proposition, and so the pruning over the years, should be less intensive, even at the expense of reduced flowering and less showy blooms.

Designing With Landscape Shrubs And Bushes – Learning To Choose Them Like A Garden Designer

A professional garden designer chooses landscape shrubs and bushes in a certain way, while an inexperienced home gardener chooses them in another. The novice tends to go for plants that he or she has seen and liked in parks, gardens, and nurseries. The landscape architect or garden designer on the other hand, while taking personal preference into account, works according to a set of principles, which unlike other aspects of design, can be readily applied by the average home gardener.

To think like a professional, do not at first have specific plants in mind, but rather distinguish between the various design functions that shrubs perform in the garden, and then choose those species that fit the design criteria you have established. It’s like a manager choosing from a list of candidates, the person or persons for a certain job in the company. Certainly, subjective factors play their part, but primarily, the hirer will be looking at the objective credentials of the candidates, such as qualifications and work experience. Here then are some of the “qualifications” that your “candidates”, i.e. your shrubs, should possess before including them in the garden.

Sheared Hedges

The role of a neatly trimmed, sheared hedge is to act either as a formal screen or as a background to some showy focal point. Not every shrub is suitable for the purpose. As a relatively formal garden element, the plant’s foliage should be neat, small, and of fine texture. Plants with large leaves and course texture, like Hibiscus for example look poor and ragged after the hedge trimmer has been at them. That is why “unspectacular” bushes such as Pistacia lentiscus or Myrtus communis make excellent trimmed hedges.

It is tempting to choose species that grow quickly, but this is not necessarily wise in the long run, as rampant plants, like Elaeagnus pungens, are more difficult to maintain on a regular basis. Undoubtedly, that is the reason why the “boring” Privet plants (Ligustrum sp.) are often the choice of the landscape professional.

Informal Screens

Shrubs that are grown as loose, informal screens are usually more suited to larger spaces as opposed to small backyard gardens. The plants can be larger, faster in growth, and have courser leaf texture, than those designated as trimmed hedges. As screens, they ought to be evergreen, and to recover well from pruning. Examples include species of Viburnum, Myoporum, Cocculus. Conifers, such as the large varieties of Juniper, are especially suitable, as they generally do not require pruning

Flowering Shrubs

A landscape bush that acts as a screen can also double up as a flowering shrub. It is worth distinguishing here between those such as Plumbago, that bloom almost continuously through the growing season, and others, like Grevillea and Callistemon, that have a brief, seasonal, flowering period. Strangely, the continual flowerers often produce negative reactions amongst homeowners, perhaps according to the principle that familiarity breeds contempt! They are best used in the farther reaches of large gardens, and perhaps avoided in small spaces. With regard to color, shrubs that sport decorative fruit should not be overlooked.

Sculptural and Emphasis Plants

I addition to screening and background functions; a number of shrubs are highly decorative as individual specimens, creating either a clear focal point or a subtle emphasis amongst a mass of “regular” plants. Yucca and Plumeria for instance, have definite sculptural qualities, while the colored foliage of purple-leaved plants creates a striking contrast. The key with such “special” plants is to use them as sparingly and carefully as possible. Nothing shows up the amateur more, than the sight of plants with purple, silver, or variegated leaves, dotted throughout the garden.

Pruning Landscape Shrubs And Bushes For Shape And Form

The prerequisite for getting the best performance from your landscaping shrubs and bushes is to be clear about their precise design role they are to play in the garden. Are they to serve as a screen, a backdrop to some special feature, are they to be grown to provide color and fruit, or is a particular specimen to be given a special role such as being limbed up into a small tree, or perhaps grown horizontally on a wall, in the espalier fashion?

Following that, successfully achieving the desired shape or form of the shrubs is a matter of choosing the appropriate form of pruning. Pruning is the most important of the various horticultural tasks, because of all the different plant types that make up the garden composition, shrubs and bushes usually require the most intervention with their natural growth habit.

The most obvious example of this intervention is with trimmed hedges or with some other form of topiary. Less obvious, but no less critical, is the need for the regular clipping and pruning of those shrubs that are grown as an informal, natural screen. If the function of such plants is to be the “wall” of the garden, that is to be green and full from the ground upwards, then pruning is necessary to ensure compact growth. Left to their own devices, most shrubs lose this compact, full growth, in time tending to grow like trees – woody up to at least eye level, and only green and leafy on top.

It is easy to prevent this during the growing season, by simply clipping back shoots that burst forward. Usually, small quantities are removed at any one time, so the plants should not be adversely affected. A hedge trimmer is the easiest and quickest method for the job, but the natural look of the shrubs can be diminished if right angles are created by the trimming. Regularly removing small quantities of tissue, prevents the need for a much heavier pruning operation, which is sometimes necessary when the bush has become loose, open, woody and top-heavy.

Some landscape shrubs of course, possess an attractive form naturally. With such plants, the constant shortening of branches and shoots spoils the natural look of the plant. Examples include Abelia grandiflora, Acalypha wilkensiana, Nandina domestica, and Plumeria rubra In such cases, selected branches, invariably old ones, should be cut to the ground, creating space for new shoots at the base of the plant to develop. Growing shrubs is very much a matter of granting preference to the young over the old!

The right season for pruning to rejuvenate individual branches or the whole bush, depends on whether the species is deciduous or evergreen, sensitive or hardy to cold. Deciduous plants from cold climates should be pruned in the winter, their dormant season, but not in the spring. Evergreens and non-hardy species on the other hand, should not be touched until all possibility of frosts has passed.

Shrubs And Bushes – Their Design Role In A Landscape Garden

Landscaping shrubs and bushes have a number of functions in the garden. In the abstract, landscape architects and designers see them as the “walls” of the garden, whereas trees and prostrate plants are viewed respectively, as its “ceiling” and the “floor”. Shrubs and bushes, by virtue of their dimensions, are the one group of landscape plants that relate to human beings in terms of scale – both trees and low-growing plants being either beyond or beneath the size that relate to people. As the usual height of garden shrubs is between 1 to 3 meters (3-9ft) it follows that people eye them without either having to look upwards in the case of trees, or downwards with flowers or ground covers. The psychological significance of this “humanizing” function of shrubs and bushes, is usually missed by the average home gardener,

On a more prosaic level, the two most important design roles of landscape bushes, is to act as a visual barrier to screen out unwanted views and as a background to focal points such as a statue, a water feature, or a mass of flowers. A background element is crucial in any design, because something only becomes “special” in relation to a mass of things that are “ordinary”. For this reason, bushes that are grown in a background role should neither be garish in color nor showy in form, but rather, green, quiet, and fine to medium in leaf texture.

On the other hand, many shrubs are a valuable source of garden color. This is a vital asset in dry climate gardens, where water use may be severely restricted, because on average, shrubs require at least a quarter of the amount of water consumed by annual flowers. In some cases as with Plumbago auriculata, established plants bloom for extensive periods without needing irrigation at all.

In the same vein, color is provided by landscape bushes that have colored foliage. Purple-leaved plants create the most striking contrasts, although they are often over-used, indeed miss-used by the inexperienced or naïve gardener. Silver-leaved shrubs are a safer bet, because silver and grey, as with white or black, are not colors, but differing intensities of light. Nonetheless, good taste demands they be used sparingly and judiciously. Leocophyllum frutescens from Texas is an example of a water-conserving bush that not only has attractive, silvery-grey leaves, but lovely purple flowers as well. Plants with gold-colored leaves make for a more subtle, gentle contrast with the mass of green-foliaged shrubs. The fruit, edible or otherwise, of many shrub species, also adds color to the garden especially at the end of the summer, when it is often in short supply.

There is another important, but much overlooked function provided by some landscape bushes. It is that many produce edible and tasty fruit. The great advantage of fruiting shrubs over fruit trees, is that they are often far less vulnerable to pests and disease. While plum, apricot, cherry, and apple trees are liable to be subject to the depredations of bark insects, and citrus trees attacked by leaf miners, shrubs such as Carissa macrocarpa, Feijoa sellowiana, and Eugenia uniflora (delicious sour/sweet berries) remain virtually untouched.

Lawn Irrigation – How Much And How Often Do You Need To Water?

There are many factors contributing to the success or otherwise of a lawn. A main cause leading to failure is a compacted soil, which lacks oxygen in the root zone, and does not allow for the adequate infiltration of water. Other vital factors include a correct mowing regime, a suitable feeding programme, and periodic de-thatching. Adequate moisture though is the single most important question as to whether a grass will succeed or not.

Firstly, how much does your grass need? This depends on where you live and the lawn type you have. The perennial grasses in general use in hot, dry climates, such as varieties of Bermuda, Zoisia, Kikuyu, or Paspalon, “consume” moisture at some 50% of the daily evaporation rate for a particular area. In central Israel where I live, this average figure during the summer months is around 8mm per day, which means that lawns need some 4 liters per square meter per day. Contact your local meteorological station, to find out the figure for your locality.

The second question is how often you should water the grass. The grass types previously mentioned are deep rooting and actually do better on less frequent, but longer watering. Such a regime encourages the roots to grow deeper into the soil, making the grass hardier to drought, pests, and disease. Assuming that the depth of soil is over 50 cm, then an established lawn can be watered every 7-10 days in heavy, clay soils, 5-7 days in medium soil, and perhaps 3-5 days in light, sandy soils. If one has been irrigating frequently, but with much smaller amounts, then it makes sense to break into this new regime carefully, monitoring the results as you go.

To provide a personal example, I watered new lawns I put down this summer 3 times a day during the first week, once a day from the second week, and so on, so that by the end of the summer they will be irrigated once a week, but with proportionately greater amounts in accordance with the changing frequency. The lawns are every bit as green as those which are watered every day. Here is an example for calculating the amount of water to be applied in a particular locality, where the daily evaporation rate is 8mm, the area of lawn 30 square meters, and the soil of a medium/heavy type.

Quantity (liters) = Average daily evaporation rate * 50% * Area of lawn (square meters) * Interval between watering

Quantity (liters) = 8(mm) * 50% * 30 (square meters) * 7 (days) = 840 liters

How long should you water for? This is quite easily calculated by dividing the quantity that is required by the flow rate. (the amount of water emitted per hour) The flow rate can be discovered by registering how much water the system emits in say 10 minutes, and then multiplying that figure by 6 in order to arrive at the amount per hour. For example, if the quantity required is 840 liters, and the flow rate is 500 liters per hour, then watering time = 1 hour, 40 minutes.

One word of caution though. This method only works satisfactorily if the irrigation rate (the quantity of water emitted per hour relative to the area ) is low enough for the soil to absorb it. If there’s a lot of run-off from your lawn, then you should change the sprinkler nozzles to ones that emit less water per unit of time. Failing that, more water has to be added to the calculation, in order to compensate for the run-off.

Lawn care In Mediterranean Gardens – Maintaining A Neat Edge

A scruffy, untidy lawn edge is one of the things that really frustrate the average home gardener. Most of us dream of having the neat, clean edge we see in fine public gardens and perhaps in some of our neighbor’s gardens as well. In cool, moist, summer climates, where grasses from seed are generally grown, there’s no great problem in cutting a straight edge with a half-moon spade a couple of times a year or so, and then maintaining that edge with garden shears or perhaps with a mechanical strimmer.

In Mediterranean and other hot, dry, summer regions however, deep-rooting, perennial species are usually grown for lawn grasses. With these, as many home gardeners are aware to their displeasure, maintaining a neat edge is far more involved. Furthermore, as these species tend to spread by sending out runners above or below the ground, the grass often turns into a noxious weed, invading the neighboring planting beds, while proving irritatingly difficult to control at the same time.

One solution is to insert a plastic edging product in the ground. These have a depth of some 10-15cm (4-6in) and vary greatly in price and quality. The cheap products have a very thin profile and are virtually impossible to keep straight in the ground, so instead of a clean line (as the photos on the package invariably show) you get an untidy wave for a lawn edge instead. The more expensive types, while being flexible enough to permit use in curved edges, are sufficiently firm, to create a line that is reasonably clean and straight.

It is an illusion to think that edging products, pricey or otherwise, prevent the grass from creeping underneath and invading the nearby flowerbed. Species that spread by means of rhizomes (stems that grow parallel to the ground but below it) such as the Bermuda or Zoisia varieties have no trouble passing below an obstruction that is 25cm (10in) deep or more, so constant vigilance is needed to cut away grass that has invaded the planting beds.

The benefit of these products is simply that maintaining the edge is easier, providing one uses a mechanical strimmer after mowing the lawn. The drawback however, is aesthetic, because the top of the product remains visible. The sight of a plastic tube running along the edge of the lawn is not necessarily a disaster, but is hardly the last word in snazzy design either!

From an aesthetic point of view therefore, there is no substitute for decent, natural materials like wooden sleepers. Sleepers from pinewood for example are not horrifically expensive, and an attractive edge with a width of about 15cm gives the lawn’s line more clarity and definition. Products from wood need to be treated for rot prior to installing, and painted with oil once or twice a year to prevent them drying out. An edge of brick paving, is more expensive to install, but does not require maintenance afterwards, so if it be suitable design-wise, can be considered as an alternative to wooden sleepers, especially as they can be used in rounded lines as well as straight ones.