The Christchurch Botanic Gardens
Information Sheets
Annual Bedding Displays
While a combination of trees, shrubs, perennials and lawn areas provide an overall balanced garden, it is the addition of annual plants that make many designs look complete and help to emphasize the seasonal aspects.
The main concentration of annual bedding is located on a site that originally consisted of several large gravel pits. These were excavated with the gravel being used to form metal roading for many early city streets in Christchurch. This area was the first to be levelled and sown in grass. For many years it was known as the Front Lawn and later named after the first curator John Francis Armstrong in recognition of his valuable services to the Gardens. Annual bedding displays in this area have changed over the years to suit the styles and trends of the day. Today the formal beds flank the northern and eastern sides of the Armstrong Lawn.
Annuals represent a large group of garden plants. They are botanically defined as plants which in one growing season germinate from seed, grow to maturity, flower and set seed. Biennials, herbaceous perennials and standardised shrubs are also often used in the annual bedding displays for added colour, height, form, texture and scent.
The diversity of annuals is vast and there are suitable species, varieties and cultivars for almost any garden situation, be it intense sun or deep shade. Many are grown for use as cut or dried flowers while others are utilised for their attractive foliage or scent. Annuals play a major role in landscaping and are frequently incorporated in mixed flower and shrub borders, container gardens, specialist areas such as cottage or wildflower gardens and are often used as fillers in newly established gardens. Annuals used in formal and informal bedding displays provide strong colour, flower in a relatively short period, add seasonal interest to a garden and are a challenge in creating imaginative designs.
The design and planning of the Annual Bedding Displays
Formal annual bedding displays are provided on two occasions each year. The first is for the spring and the second for the summer period. The annual bedding displays at the Christchurch Botanic Gardens are ideally situated, having a neutral back drop of mature trees and a large expanse of lawn. The nearby buildings and adjacent trees provide the necessary shelter from prevailing wind but are far enough away to prevent excessive shading and root competition. A wide range of plant heights are made possible because of the length and width of the beds. The soil in this area is a light, fertile, well drained loam with a near neutral pH.
During the spring and summer months plants in each seasonal display are evaluated on their performance. Careful note is taken of successful displays, ideal combinations and occasional failures for future reference. The five main points considered when planning planting positions of annuals are colour, height, flowering period, form and texture. Hardiness and suitability for the growing conditions are also assessed.
Colour in the annual bedding displays, be it foliage or flower is used in a way to ensure a sense of unity. A colour wheel is used to plan colour combinations therefore achieving similar or complementary displays. Plants are grouped en masse so that a unified picture is presented. Dominant colour spread throughout the displays gives a feeling of repetition and rhythm. As various annuals are dominant at certain times, colour will often look after itself as colours within these groups are usually harmonious. White flowered plants are sometimes used in the displays as links between various colours.
Plants are also arranged according to height and are graduated with low plantings to the edge and taller ones to the centre of the displays. Bulbs and standardised shrubs are used in the centre planting to give a tiered effect with added impact. Where practical the soil level is slightly crowned to assist in projecting the display toward the viewer.
Records are kept concerning the length of time a particular annual will take to reach flowering stage and the period of time it will continue to flower. These records are used to space groups of early or late flowering annuals regularly throughout the displays helping to prevent large flowerless areas.
Plants with differing forms and textures are used where possible as they provide interesting contrasts and visual appeal. Some annuals in the displays are worthy of growing for their foliage alone.
There are many factors considered when choosing annuals that will be suitable for growing in the bedding displays. The ability to withstand hot, dry, windy conditions, frost hardiness and growth rate are just some of these.
Each annual bedding display is prepared one year in advance of the date of planting. The seed is then ordered with careful consideration being given to a balance of new introductions, (some of which may have been trialed in the evaluation plots) with other well proven species, varieties and cultivars.
The majority of the annual bedding plants are sown and grown on under commercial contract. In accordance with a detailed specification, the seed is sown and grown on in a soiless mix with appropriate fertilisers and preventative sprays to ensure a well rooted, healthy, compact and uniform plant of good colour is produced.
Bulbs including a selection of Hyacinthus, Narcissus and Tulipa are selected and/or ordered one year in advance of planting for inclusion in the spring bedding displays. Standardised shrubs including Abutilon, Fuchsia and Heliotropium are grown from cuttings in February, ready for planting out in October/November for inclusion in the summer bedding displays. The standardised plants are trained as standards by having their lower lateral shoots removed to a height of 900mm when the plant is then encouraged to bush out and form a rounded head. Grown in polybags in the nursery glasshouses over winter, these plants are hardened off in a shadehouse before being planted out.
The maintenance and care of the Annual Bedding Displays
The annual bedding displays are one of a number of high maintenance areas that require much attention throughout the year.
In March/April plants in the summer bedding displays are removed from the display beds in preparation for the planting of the spring bedding displays. The standardised shrubs are removed and the remaining plants composted. In October/November plants in the spring bedding displays are similarly removed in preparation for the summer bedding displays. In this instance the bulbs are carefully dug up before being cleaned and stored in aerated racks in the potting facility for replanting the following March/April. The remaining annuals are composted.
After removing all plants from the display beds they are cultivated by digging to a depth of approximately 150mm. If the soil is lacking in organic matter, compost is spread over the area to a depth of 40mm before the area is cultivated. Continual growing of annuals in one particular area breaks down the soil's structure and drains important nutrients. The incorporation of compost provides ideal conditions for beneficial soil bacteria to thrive, gives a deeper rooting medium for plants, improves air and moisture penetration and lifts the soil temperature. An application of a slow release fertilser such as 'Osmocote Plus' at 60gm/m2 is usually necessary for peak plant performance. Prior to planting the soil is lightly consolidated by heeling, the surface raked to a fine state and lightly mounded towards the centre of the display bed to aid in drainage and appearance.
Working from a prepared planting plan, a marking rake with adjustable metal prongs is used to mark out the planting rows. The first to be defined are the two edging rows around the perimeter of the bed. Then, working alternately from one side of the bed to the other, rows are defined along the length of the bed with the last being the centre row. Marks are then made across the centre line to show where the first row of plants will be positioned. Row widths and planting distances depend on the type of annuals and their rate of growth. Most annuals however, are planted between 250 and 300mm apart. Plants are carefully removed from their boxes with as much root per plant as possible and placed adjacent to the centre row. Starting from one edge of the display bed and working forward along the length of the row, the annuals are planted using a trowel. Planting holes are made wide and deep enough to take the roots of the plant comfortably so that when planted the plant will be at the same depth or slightly deeper than it was in the seed box. The next rows to be planted are those on either side of the centre row. The plants in these rows are planted out alternately to those in the centre row. The remaining rows are planted out in similar alternate fashion including the two outer edging rows aroung the beds perimeter.
It is at this time during the planting of the spring bedding displays that groups of selected bulbs are planted. These dot plants are spaced between the annual plants in the centre planting only. The bulbs are planted to a depth of twice their diameter. After the planting of the summer bedding displays the standardised dot plants are planted. Like the groups of spring flowering bulbs, the standardised shrubs are spaced between the annual plants in the centre planting only. Using a spade the shrubs are planted to the same depth as they were in the polybags. The temporary stakes that supported these shrubs in the glasshouse/nursery are removed and replaced with more substantial green painted metal stakes, which are hammered in to a depth that is lower than the ultimate height of the plant when in flower. Two unobtrusive ties that will not damage the plant are looped around the plant stem and tied to the stake.
Display beds are lightly hoed, with soil from around the edges being lightly flicked up towards the centre of the bed using a hoe. The beds are then thoroughly watered using portable bar sprinklers. Hoeing of the display beds throughout the year allows air and moisture to penetrate to the roots of the plants while at the same time exposing unwanted weeds. The clipping of edges and the pinching back of leggy annuals to produce a more compact plant are carried out at regular intervals throughout the season. Checks are constantly being made to ensure that all lateral shoots below 900mm on standardised shrubs are removed and that the rounded head is kept in shape by lightly pinching back. Extra plants grown on each season to replace those that have either died or been vandalised are planted out if and when necessary.
Few sprays are used for pest and disease control in the annual bedding displays, with only natural sprays now being used to combat any serious infestations that may occur. An application of a slow release fertiliser is made in the spring to encourage growth at this time of the year. An automated sprinkler system is used during the early morning to irrigate various sections of the annual bedding displays as and when necessary.
Spent flowers are removed regularly not only for appearance but to encourage further flowering, thus prolonging the flowering season. As well as for aesthetic reasons this helps to reduce the incidence of pest and disease build up.
Click here for a list of common annual, biennial and perennial plants grown in the Annual Bedding Displays. |
