How to Grow Tender Geraniums (Pelargoniums)
Tender geraniums (pelargoniums) are a fabulous splash of colour in summer, flowering for
months on end in pots, window boxes, hanging baskets and flower beds. Easy to grow and
drought-tolerant, they’re perfect for busy gardeners and ideal for small spaces. Get the best
from your geraniums with our simple growing guide.
When your plants arrive
-
Unpack the plants immediately and check the compost to ensure it has not dried out in
transit. Water with a fine spray, or sit the plants in a tray of shallow water if the compost is
dry. - Pot on as soon as possible (preferably within 24 hours) after they have had time to settle.
Potting on and planting out
-
Handle each plant by the plug root ball, rather than the stem to avoid damage.
Pot each plug into a 7.5cm (3in) pot using a good multi-purpose compost.
Grow on for a few weeks in a greenhouse or a bright, frost-free place, but avoid
direct sunlight. -
Keep moist but do not over-water. If very cold weather is forecast, cover with a layer
of fleece. -
Harden off your plants before planting them out by placing the pots outside during
the day and bringing them back in at night. After 7-10 days, the plants will be ready
to plant out
How to care for geraniums
-
Plant in a sunny spot in well-drained soil. If planting in pots or hanging baskets, use a
multi-purpose compost. -
Geraniums are drought-tolerant and don’t like sitting with their roots in wet
compost, so don’t overwater them. -
Apply a balanced liquid feed fortnightly until the flowers appear, then feed
fortnightly with high potash feed such as tomato food. -
Deadhead faded flowers regularly. This encourages the plant to keep flowering and
also reduces the risk of fungal disease botrytis in wet weather.
How to protect geraniums over winter
-
Move plants into a greenhouse or place on a sunny windowsill before the first frosts.
To save space, the plants can be cut back to 10cm (4in) high. -
Reduce feeding to once a month in autumn, and feed sparingly or not at all in winter.
Water plants that are still in growth very sparingly in winter – plants that have been
cut back will need practically no watering through winter -
In spring, harden the plants off before moving them back outside once frosts are
over, in late May or early June.
Pests and diseases
Geraniums may be prone to the following pests and diseases. Read more about how to
control common plant pests and diseases here.
- Pests
- Vine weevil larvae (especially container-grown plants)
- Aphids
Diseases
- Grey mould
- Rust