Complete Advice for Growing Geraniums.
Planting, Ongoing Care, Pests & Diseases and FAQ.
You might often hear people saying Pelargoniums when talking about geraniums and heres why.
Pelargonium hortorum, also known as summer bedding geraniums, are classed as tender annuals in the UK.
This type of geranium will grow, flower and die in one season, once the first frosts arrive.
However, some of the scented leaf varieties of pelargoniums survive lower temperatures as long as they are brought inside before the first frost and are kept in bright, dry conditions and are completely frost-free.
Geranium sanguineum, also known as true Geranium or Meadow Cranesbill, are hardy herbaceous perennials displaying a myriad of dainty looking pastel coloured blooms.
In flower all summer, the flowers and foliage die back in winter and reappear the following spring.
This type of geranium is ideal as a low-growing ground cover plant and is used widely in herbaceous garden borders.
For the purpose of this guide we will refer to the two types are annual Geraniums and perennial Gerniums.
Annual geraniums are bright, colourful and reliable, summer bedding geraniums are easy to grow and drought tolerant. They are low maintenance plants and flower all summer until the first frosts. Originating in South Africa and brought to Europe in the 17th century, there are countless varieties and colours to choose from, making geraniums one of the most popularly grown summer plants in the UK.
Perennial geraniums are long-lived herbaceous hardy plants. They are easy to grow, do not need any special soil requirements and can flower over many months in the summer. Originating in Europe and areas of temperate Asia, perennial geraniums grow well in poorer soils and are particularly good to grow in coastal areas and soil conditions with sandy chalky structures. They have a compact rhizome root system that lives just below the surface of the soil and remains dormant in the winter months. New growth begins in spring as the temperatures warm up with interesting looking foliage and five-petalled flowers that often display intricate veining.
Planting Geraniums.
Where to plant Geraniums?
Annual geraniums thrive in hot, dry sunny areas of the garden. There are many varieties of these geraniums including upright, trailing, ivy-leaved, variegated, zonal and scented leaf and with such a huge array of colours and leaf form, geraniums are must have plants for summer displays. Upright varieties are super in hanging baskets, patio containers and window boxes can look effervescent filled with trailing geraniums and terracotta pots look great when planted up solely with red geraniums giving a Mediterranean feel to displays.
Perennial geraniums are happy in sunny or partly shady areas of the garden, they are loved by hoverflies, bumble bees, honey bees and butterflies as well as beneficial beetles.
When to plant Geraniums?
When you receive your annual geranium plug plants, water them and plant up within a few days of arrival. Using a good quality peat-free compost, pot up your plugs individually into 13 cm pots or use 4 or 6 Pack Cell Plant Trays. Once your geranium plug plants have been potted on and labelled, water them in well and grow on for 5-6 weeks in a bright frost-free area such as a greenhouse, conservatory or kitchen windowsill. Geraniums can take a little longer to grow on than some of your other plug plants, so patience is key as they are worth it!
You can pinching out the first flower buds will ensure that the plant will put its energies into a good root system and leaf growth which will result in a stronger, bushier plant with more blooms. However, be aware that flowering will start a little later, so we wouldn't advise pinching the flowers off our smaller geranium plugs that come in trays of 20, 40 and 350 if you recieve them in May!
Keep plants frost-free until mid/late May and then harden off plants by bringing them outside during the day and bringing them inside again for night time protection for a few days to acclimatise plants to outside temperatures! Plant outdoors in their final positions when the risk of frost has passed in your area.
How to plant Geraniums in the ground.
Prepare the area by digging over and loosening the soil structure and ensure that soil is free-draining. Adding homemade compost or a soil conditioner will improve the overall structure of the soil. Once ready to plant outside, space at around 20-30 cm (8-12") apart, preferably where they will receive plenty of bright daylight or sun for maximum blooms throughout the summer.
How To plant Geraniums into hanging baskets and containers.
Using fresh peat-free compost add some slow release feed granules to the mix before planting. For a 30 cm (12”) standard basket or container using only annual geraniums we would recommend using one upright geranium as the central plant with four/five either trailing or upright geraniums around the sides.
Ongoing Care for Geraniums
Watering Geraniums.
Geraniums are fairly forgiving if you forget to water them for a day or two even in high summer. In fact, once established they will prefer too little to too much water. Overwatering and being left in standing water will eventually lead to the roots rotting.
Feeding Geraniums.
Feed throughout the flowering season with a high potash feed which will promote strong growth and continuous blooms. A diluted measure of Tomorite feed once a week can be used.
Deadheading and pruning Geraniums.
To get the best from your annual geraniums, remove faded blooms as they go over. Cut back to the base of the flowering stem using sharp secateurs or use your forefinger and thumb to snap the stem off to remove it from the main stalk. This will encourage more flowers and keep your display looking fresh and tidy.
Staking Geraniums.
Summer bedding geraniums do not need staking as they are self supporting, trailing varieties naturally cascade and do not need staking. Occasionally perennial geraniums, depending on the variety, will need a small hoop support to lift them off the ground especially if the foliage is encroaching onto pathways. But, if preferred, they can always be trimmed back with garden shears to neaten a pathway.