Gladiolus
* It is best to wait until the threat of frost has passed before planting.
- Botanical Name
- Gladiolus x grandiflorus
- Family
- Iridaceae
- Plant Type
- Bulbous corm
- Size (HxW)
- 1-2m x 15cm. Glamour: 70-100cm x 15cm.
- Depth & Spacing
- Plant the bulbs approximately 15-20cm deep and 15cm apart. Gladioli look great in dense clumps. Planting them a little deeper, to 20cm will help shore up the stem and reduce the need for staking. If you are planting a lot of them, why not dig a trench, add some manure, dig it through then toss your bulbs in on top, refill and water in. You can still stagger/increase the flowering time by adding your bulbs at weekly intervals (see Notes).
- Soil
- Moderately fertile to humus rich, well drained soil is ideal. They tend to rot in boggy soils. If your soils are poor, prepared soil is best - to ‘prepare’ your soil, add lots of well-rotted animal manure or compost and potash to the soil prior to planting, this increases nutrients in the soil and can increase the quality of the flowers into the future and strong plants have less disease. Ideally work the manure through the soil 4-6 weeks before planting, digging deeply to ensure good drainage. Don’t worry if you miss the boat, just add some at the time of planting. If your soil is already humus rich don’t worry too much.
- Aspect
- Full sun. Protection from strong winds is also advisable - or add stakes.
- Climate
- Cool to Sub Tropical
- Frost
- Half hardy. Lift and store your bulbs over winter if you live in an area that receives hard frost, or give them a heavy mulch for protection in autumn.
- Water
- Water them in well to help activate the growth. Keep moist in active growth. Fertiliser: Apply a fertiliser high in potash during flowering, this will help them to last longer and increase their flowering capability next season. If you want to DIY, blend of mushroom compost (to sweeten), blood and bone (to feed) and potash (for flowers) is ideal. Or use a pre packed fertiliser of your choice.
- Flowering Time
- Summer. The timing is somewhat determined by planting dates (see Notes).
- After Flower Care
- Remove spent flowers and foliage once it has yellowed.
- Storage
- If required, lift the corms once the foliage yellows (a month after flowering) - toss away the old, shrunken corms and keep the fresh new stock - smaller ones may take a year to bloom. Cut the foliage to within 5-6cm from the corm and allow them to dry thoroughly before storing in a cool, dry and airy spot. The bulbs can also be dusted with an insecticide before storage or soaked in pyrethrum - thrips must be dealt with prior to storing corms.
- Notes
- The bulbs can be planted on a staggered time line over one or two week intervals to create a continuous display of flowers over a longer period. The bulbs will flower approximately 90 -120 days after planting. (The warmer the weather, the quicker they are to start flowering). During growth, keep an eye out for thrips, which will cause silver streaking in leaves and flower buds. It is a good idea to keep the area free of weeds which can act as hosts, try blasting them off with a hose, encourage their predators (you can order some of these online), neem oil can be used, or a pyrethrum spray. If plants have poor air flow, rust fungus may occur, remove affected foliage and in extreme cases control with your choice of fungicide. Your flowers will last longest if cut when 1/3 are open, cut them at a diagonal angle so they better take up water and remove the top few green blooms which will just flop. When cutting allow around half a stem and the rest of the leaves to remain and feed the bulb for next season.
