When growing blooms for exhibition, the highest quality blooms are needed for a specific date. Various techniques, including disbudding, can be used to manipulate the flowering date. To delay flowering of the main bud, allow side buds to grow on side shoots up to 5cm (2in) long before re-moving them. The time from securing the bud until the bloom is ready varies according to the species and variety. With, for example, this period is six to nine weeks, but only experience will really tell.
It will be necessary to protect exhibition blooms from heavy rain, hail and high winds. To carry such large blooms without breaking, the plants need to be grown in a sheltered spot and thesupported. Individual blooms can be protected from the weather by-greaseproof paper bags. Spray or dust the buds to get rid of any pests before putting on the bag.
For very valuable blooms, construct an open-sided timber framework with a sloping roof around and over the plants.
Cover the top with tough, clear polythene or PVC sheeting once the flowerbuds begin to show colour – but no earlier or plants may develop weak, stragglythe ground, then train them up a new cane further along the row.
The right site
Rich, fertile soils generally produce the largest, lush plants and adding the correct fertilizer after deadheading can improve flowering . But in some cases too rich a soil or too much nitrogen fertilizer can encourage luxuriant foliage at the expense of. Many , including nasturtiums (Tropaeoliim majiis), can be disappointing on well-prepared soils, yet put on a showy on poor soils in a sunny spot.
Succulent plants, such as stonecrops () and mesem-bryanthemums, are reluctant to flower well when the soil is too moist or too rich – in nature they may only flower and set when the life of the plant is threatened by drought or intense heat.
Some blooms can stand up to the weather better than others. Highly-bred, showy blooms, such as double petunias and the old-fashioned, rosebud zonal pelargo-niums, such as ‘Apple Blossom’, often suffer in wet weather.
However, the smaller-flowered single petunias and pelargoniums are more resilient and recover quickly after summer downpours.
When choosingto grow together, try to combine a mixture of sun and drought-lovers, such as pelargoniums and gazanias, with some tough plants, such as semperflorens (syn. B. x carrierei) and busy Lizzies, which can withstand a wet summer.
Aspect is often very important in determining whether or not you get a good display of flowers. For example, a sun-loving plant grown in shade may produce a reasonable amount of foliage, but few or no flowers.