How to Grow Naturalising Gladioli Corms
Grow Guide #2619
Binomial name: Gladiolus nanus
Life Cycle: Perennial
This 'How to Grow' guide details everything a home gardener needs to know to plant, grow and care for Naturalising gladioli (Gladiolus nanus).
When to Plant Naturalising Gladioli Corms
Use the table below to identify the best time of year to plant naturalising gladioli corms in your climate.
Naturalising gladioli plants are best grown in full sun. Choose a location that will receive at least 6 hours of full sun each day.
Naturalising gladioli plants need a loose, well drained soil enriched with organic matter. Prepare soil by weeding it thoroughly, digging it over to at least a spade’s depth to loosen the soil, and adding aged animal manure or compost. Organic matter can be dug into heavy soil to lighten it so roots can grow freely. Keep the area free of weeds until planting. Learn more about preparing soil for planting here.
Naturalising gladioli plants can be grown in containers. If possible choose a variety that’s recommended for container growing. Use a good quality potting mix and make sure your container is large enough for mature plants; a minimum of 10 litres is recommended for naturalising gladioli. During the growing season, keep in mind that container grown plants may need additional fertiliser to encourage healthy growth.
How to Plant Naturalising Gladioli Corms
Naturalising gladioli corms should be planted directly in their final position in the garden or a container.
- Plant individual corms 10cm apart and 7cm deep with the tip pointing upwards.
- Cover with soil and water in well.
- Keep soil moist but not wet until shoots emerge.
How to Grow Naturalising gladioli
Naturalising gladioli plants may need watering during the growing season. Water when the soil is dry about 5cm below the surface (test this by scratching away a little soil with your finger). Water deeply in the early morning or late afternoon. Avoid watering the leaves of plants to avoid fungal diseases. Learn more about watering here.
If soil was well prepared no extra fertiliser should be necessary. In poor soil or to give your plants an extra boost, application of a balanced fertiliser or one formulated for flowering plants can be beneficial:
- apply liquid fertiliser at the recommended rate when buds begin to form; and
- apply slow release fertiliser at the recommended rate in early spring.
Naturalising gladioli plants should flower in approximately 100-120 days.
Deadhead naturalising gladioli flowers regularly during the growing season. Using sharp secateurs or snips cut fading or dead flowers off just above a set of leaves. Removing old flowers regularly will encourage plants to produce more flowers. Learn more about deadheading flowering plants here.
If growing naturalising gladioli for cut flowers, use sharp snips or secateurs to cut the longest stems possible, removing the lower leaves and placing the stems immediately in a clean bucket of water. Learn more about cutting and conditioning homegrown flowers here.
Naturalising gladioli can be left for several years to naturalise in the garden. If clumps become overcrowded corms can be lifted, stored and replanted in autumn.
To lift corms wait until the foliage turns yellow. Cut the foliage off at ground level, then use a garden fork to lift corms from the soil, taking care not to damage them. Spread the corms on a wire rack in a cool, dry place for 10-14 days to dry them. Then store the corms in a net bag until it is time to replant them in autumn.
Common Problems when Growing Naturalising gladioli
Like all plants, naturalising gladioli is susceptible to some pests, diseases and other problems. Below is a list of the most common problems gardeners encounter when growing naturalising gladioli plants:
- Aphids are small (2-4mm long) sap-sucking insects that congregate on the new shoots or the undersides of leaves. They can cause leaves to wilt or become discoloured, and also excrete honeydew which can attract ants and other insect pests. To manage aphids, remove them by spraying with a garden hose, apply a soap or alcohol spray, or encourage predatory insects to your garden. Read more about aphids here.
- Powdery mildew is caused by fungal spores reproducing on the leaves of plants. First showing as white spots on leaves, affected areas can spread quickly to cover the entire leaf surface. While rarely fatal, powdery mildew can reduce yields. Water plants at soil level (not on leaves) to prevent spreading spores, allow good air flow between plants, remove affected leaves and if necessary spray with an appropriate fungicide or homemade spray. Read more here about powdery mildew here.
- Rotten corms are caused by pathogens entering corms after sitting in cold, wet soil or being temporarily waterlogged. Corms may show obvious signs of rot or have no roots or shoots. If soaking corms before planting, do not soak them for longer than recommended. Plant corms in free-draining soil, raised garden beds or containers. If growing corms as perennials, lift and store them over winter and replant in spring.
- Thrips are black, beige or white flying insects (<1.5mm) with larvae that suck tissue from leaves and petals, leaving behind very small white or transparent markings. While not usually causing serious damage, the marks affect the look of flowers and foliage and thrips can also transfer pathogens from one plant to another. Wash thrips from affected plants using a garden hose, encourage predatory mites and lacewings with companion planting, or spray with soap, eco-oil or neem oil.
- Slugs and snails are molluscs that feed on tender leaves and shoots, mostly at night, leaving slimy trails behind them. Control them by removing their hiding places, keeping free range poultry, collecting them by torchlight or by placing traps. Read more about slugs and snails here.