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| Gladiolus | Common name; Sword lily |
Gladioli originate from South Africa and are members of the Iris family.
The botanical genus is from the Latin for a ‘Small sword'
They come in varous sizes and colours as can be seen here
Large flowered:- 100mm to 175mm across.
Small-flowered or Butterfly group: 50mm to 100mm across.
Primulinus:- 50mm to 75mm across.
Miniature:- 35mm to 50mm across.
The best time to cut stems for arrangements is when the first (lowest) bud is opening, after cutting, stand the stems in at least 300mm (12”) of water.
Week 4; Check the corms occasionally during the winter and discard any that show signs of disease.
Week 12; Raise Gladioli from Cormlets / Spawn
This is the main method used to increase a particular gladiolus cultivar.
It is the cheapest and easiest method to increase gladioli stock, and as it is vegetative propogation, the flowers produced, will be identical to the parent plant.
Cormlets are the tiny mini corms found around the parent corm.
These can be detached and cleaned, then stored in a dry, frost free place, in paper envelopes.
Cormlets are best sown in a nursery bed, in fact the earlier the better, providing the soil is warm, small quantities can be sown in boxes or pots.
To prevent infection from disease, it is better to use ground that has not grown gladioli for a few years, or use sterilised potting compost if they are to be grown in pots/boxes.
Before planting it helps if the outer brown skin or husk is removed, or at least cracked by pressing the cormlet gently between your finger and thumb.
Some growers soak the cormlets overnight in lukewarm water to assist with germination.
Sow the cormlets on a thin layer of sharp sand (to assist drainage), in rows 50mm (2”) deep and 50mm(2”) apart, (a little deeper if the cormlets are quite large), the rows should be at least 100mm(4”) apart.
Label each cultivar as necessary.
Signs of growth should appear in one to four weeks dependant upon variety
Throughout the growing season; never let the young plants dry out, and take the usual precautions against pests and diseases.
It is also important to keep the area weed free, the young plants do not want any competition for nutrients at this stage.
Some cormlets, may try to flower in their first year.
It is better that these small flower spikes are cut off, so that the plants energy is put into corm formation.
Harvest the corms as soon as the foliage begins to die back.
If the leaves remain green do not leave them any later than the end of September or early October.
Cut the foliage off as close to the corm as possible, and trim the roots.
Allow the cormlets to dry off in a dry airy spot that is out of direct sunlight.
After drying, normally two to three weeks, clean the small corms and store them as recommended for the large gladiolus corms.
Subject to the size of the cormlet after the above treatment, they may require a further year of the same treatment before they are of flowering size.
Week 13; To obtain earlier flowers place the corms on top of pots or cell trays filled with potting compost at a temperature of 13°C (55°F)
The corms will soon sprout and can then be planted out during May in the usual manner.
Watch out for aphids infesting the young sprouts.
n.b. At planting out time take great care not to break the brittle root system
Week 15; or as soon as the soil is workable prepare it for planting
Rake in bonemeal at the rate of 80-100gms (3-4oz) per sq.m
Week 18 ; Plant out batches of corms at fortnightly intervals from now until Week 26 to extend the flowering season.
Plump, high-necked corms with a small root scar produce better plants than the larger, fatter corms with a broad root scar.
Spacings;
Space out corms according to type
A simple way to work out suitable spacing is to divide the ultimate height of the plant by four, e.g. 1200mm (4ft) high divided by 4 equals 300 mm (12") apart.
n.b . If the height is unknown; plant out 300-400mm (12"-16") apart.
Small-flowered or primulinus gladioli, can be set 150mm (6")
Plant the corms 100mm (4”) deep in heavy soil, and 150mm (6”) deep in light soil.
On heavy soils place corms on a drainage layer of sandy compost
Plants may need some support ( circa week 30 ) to prevent stem damage, particularly if growing in windy positions.
Do not plant too shallow or the plants may topple over when in full bloom.
Week 22; Do not hoe or apply fertiliser until the young shoots appear, usually 2-4 weeks after planting out.
Apply a light top-dressing of fish manure around the young shoots.
Hoe often, to check weed growth and to aerate the soil.
n.b. Hoe very shallow to avoid root damage.
Week 23; Keep a look out for pests such as thrips (thunderflies) and red spider mite, treat as necessary
Avoid applying sprays to opening blooms, especially in bright sunlight.
Week 28; Withhold water until secondary roots have formed, eight to ten weeks after planting
After that, water generously, particularly during dry periods after the flower spike has appeared.
Gladioli must never want for water, particularly from the time the first flower spike shows.
Give at least 1 gallon (4.5 litres) per four to six plants.
Staking is usually unnecessary, except for the large-flowered hybrids or if the plants are grown in exposed positions.
Week 41; Lift the plants
Lift gladioli with a fork when the foliage begins to turn yellow-brown or six weeks after the last flower fades.
Take care not to bruise the corms.
Remove any soil sticking to them, and cut off the main stem 25mm (1") above the top of the corm.
Allow them to dry for a few days.
Week 42; onwards; Prepare for next year by digging the beds, and forking in well rotted garden compost or farmyard manure
Gladioli do best in well-drained soil in a sunny position
Week 43; Break away and discard the base plate (previous years corm)
Pull off the tough outer skin on large corms, and also remove the small cormlets and store these separately if they are wanted for propagation.
Dust with green sulphur.
Once cleaned, store the corms in a dry airy place, with a minimum temperature of 10°C (50°F)
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