How to grow freesias
Brightly coloured flowers make freesia amongst the prettiest of plants and they are great for long-lasting cut flowers. Prepared corms planted outside in April will flower in late summer or they can be grown in a cool greenhouse for spring flowering. Here's all you need to know to get the best from these lovely plants.
- Grown from corms (bulbs)
- Popular cut flower with captivating scent
- Ideal for containers
- Plant bulbs in autumn
- Grow outside in mild districts or city centre locations
- Increase your stock by planting corm offsets or sowing seed
- Freesia are available in indvidual flower colours with single or double blooms
All you need to know
What are freesias?
These are fleshy, rounded, underground storage organs, usually sold and planted while dormant. Examples include daffodils, tulips, hyacinths, lilies, onions and garlic. The term is often used to cover other underground storage organs, including corms, tubers and rhizomes.
Freesias are sold as prepared or unprepared corms (see Planting below for more details on which to go for).
These delicate plants are vulnerable to cold, and can usually only survive a few degrees of frost, so usually grown in containers in the greenhouse and house. However, if you have well-drained or sandy soil in a sheltered sunny spot, by a house wall for instance, it is worth assessing your garden for a microclimate that may suit the growing these plants outdoors.
If you willing to provide protection from the cold for these plants, or have the right conditions outside, the only choice remaining is what colour to go for - the choice is yours!
Microclimates: assessing your garden
RHS hardiness ratings
Freesias are available at garden centres in packs of corms (bulbs) for spring planting. For a larger range of these lovely flowers you’ll need to try specialist bulb nurseries such as RV Roger and J Parkers. Most will deliver by mail order.
Find the one you are looking for by using our RHS Find a Plant.
When to plant freesias
- Prepared corms: These are heat treated to mimic South African conditions and to give you an earlier display. You can buy these corms in spring for flowering in July and August but they only flower at this time for one season
- Unprepared corms: These are available in late summer for planting outdoors in August or September in mild areas with little or no frost. The corms can remain in place to flower in spring the following year
Indoor or greenhouse planting
Get your indoor corms to flower from January to April by planting in containers (see below) between August and December. October planting should, under ideal conditions, give you flowers in March for four or five weeks.
How to Plant Freesias
In the ground:
During April, plant corms 5cm (2in) deep in well-drained soil in a sunny sheltered site with twiggy sticks for support.
- You can use a mix of two-thirds loam-based John Innes No.2 potting compost and one-third horticultural grit
- Space corms 5-8cm (2-3in) apart with the corm tips just above the level of the compost
- Water gently and place in a cool, frost-free area such as a coldframe at 5°C (41°F) for three to four weeks
- Transfer pots to a cool greenhouse or conservatory and provide a temperature of 10-15°C (50-60°F) through winter
- Give your plants as much light and ventilation as possible
- Don't let the plants dry out
- Apply a high potassium fertiliser, such as Phostrogen or tomato fertiliser, every one to two weeks once the first buds are seen
Keep pots of freesia in a cool place 5°C (41°F) for three or four weeks followed by higher temperatures 10-15°C (50-60°F) with good light and ventilation
Watering and feedingWater freely when the plants are in growth.
After your freesias have finished flowering cut off faded blooms (see below) and continue watering and feeding until the foliage begins to wither and colours yellow or brown then stop watering. You will need a period of at least eight weeks of growth to encourage offsets. If you are growing them on for another year, the foliage needs to dry off by early July.
Storing freesia cormsAfter you have dug up the corms, a dry warm period is required to 'ripen' them (encourage flower bud formation). Store your dry corms in a paper bag at about 26°C (80°F) with a humidity of 75-80% for between 14-20 weeks. A warm airing cupboard or conservatory would be good places to try.
DeadheadingYou can cut back spent flowers at the base of the flower stalk, if seed is not required for propagation. This will prevent the plant spending energy on seed production, conserving resources in the bulb for next year’s display.
Cutting back bulb foliageWait for a minimum of six weeks after the end of flowering before cutting back the dead foliage, and ideally only remove foliage when it is yellow or brown and straw-like. Until this time, the bulbs should be watered and fed as above. Also, do not tie or knot the leaves.
You can propagate from seed but it can take about six months to germination and seedling stage, and they will take time - a few years to flower:
- Cover seed with warm water and soak for 24 hours to soften the hard seed coat
- Germinate in the dark with bottom heat at 13-18°C (55-64°F); you can cover pots with foil
- Seedlings should emerge after a few months
- Pot seedlings individually, dont allow seedling corms to dry out
- Grow on at a minimum of 5°C (41°F) and a maximum of 10°C (50°F)
Outside, they can also suffer frost damage. Depending on how severe the frost is, typically leaves turn grey and translucent, then collapse. Flower stems can soften and then flowers collapse.
Freesias are susceptible to pests such as:
- Aphids feeding on the foliage
- Glasshouse red spider mite on the leaves
- Slugs and snails eating the foliage
- Mice and voles can eat the corms
Freesias can be affected by diseases such as:
- Plant viruses
- Grey mould
- Fungal leaf spot, blue mould in over-warm moist storage conditions
- Sclerotinia disease
If you are a member of the RHS, you can use our online Gardening Advice service via MyRHS on the RHS website.
The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.