Gladiolus, gladiolus – plants, care and wintering

Gladiolus belonged to the onion flowers: they can thicken the lower part of their stems and leaves in a fleshy way for the purpose of propagation and to store nutrients for lean times like winter. Such a flower bulb consists of several onion skins in a mostly dry bulb cover and juicy (sensitive) inner leaves, with the bud in the middle and a shortened stem part (onion slice) at the base.

If you plant an onion in the ground, the edge of the onion slice will root out into the ground all around. The bud develops upwards. In the case of gladioli, each bulb develops a flowering stem with two or three leaves and a flower spike. The best-known and most popular gladioli are large-flowered hybrid forms created through breeding.

They also develop from very large bulbs. They should be placed in the bed at least 30 cm apart. This gives the bulb and plant enough space to grow. But there are also smaller gladioli that would be planted at a distance of 10 cm.

Gladiolus bulbs can be planted as early as late autumn if you live in an area with a mild climate. In cooler regions, it is better not to plant the gladioli in the ground until spring or early summer, from mid-May to July. With a little planning when planting the bulbs, you can extend the flowering period of the gladioli. It is very short at about two weeks. However, if you plant gladiolus every 10 days or two weeks from mid-May to early July, they will also flower with a corresponding time delay. So you can enjoy blooming gladioli until the beginning of October.

The root developing bulb skin (flat side of the bulb) must face down when the bulb is planted. You should bury the bulbs up to a good two-thirds in, because the plants will become quite heavy later on. Burrowing gives them support. However, the part from which the flower shoot is to develop should lie freely above the ground.

You can also purchase your gladioli as pre-grown plants. You can see exactly what color the flower will develop later. You can also plant the plants you have brought forward later. So that the gladioli are not damaged by frost even in very harsh regions and still bloom quite early.

The right location

The best location for gladioli is sunny and well protected from strong winds, as the flowering plants originally come from Africa and the Mediterranean region and love warm soils.

Gladioli need a soil with very good drainage, heavy soils should be mixed with sand. Poor soils should have a little rotted cattle manure or mature compost mixed in before planting.

maintenance

Gladioli really do need a lot of water to develop their extraordinarily large flower heads, so you’ll need to water them regularly with a garden hose, unless it’s raining non-stop.

The soil should always be evenly moist and never too wet. Mulching the beds around the gladioli helps a little to keep the moisture in the soil fairly balanced. When in doubt, always water a little too little, gladioli do not like waterlogging at all.

A flowering plant fertilizer helps with the development of the flowers, and the very large-flowered gladioli should be given a small stick to the side so that the flowers do not break off. For several gladiolus beds, the alternative is to lay a net with coarse mesh over the entire bed when the stems are still without flowers, through which the flowers can then develop and find support. Whether that looks good is another question, planting a smaller and more resilient variety would certainly look more natural.

Use gladiolus flowers as cut flowers

The magnificent gladioli are often planted with the aim of providing the garden owner with fresh cut flowers all season long.

This is how you should cut the flowers so that you can enjoy them for as long as possible: The first flowers can be cut when the second bud on the flower spike is just opening. When the gladioli develop normally, this is the case in just a little to a good three months after planting, but there are also slow-growing varieties and if the early summer is very cold, the development also slows down.

If you cut the flowering shoots, you should leave the leaves in place, the gladioli will continue to grow even without flowering, they will continue to be cared for as usual.

The flower itself should be carefully freed from the top flower bud as soon as the gladiolus is in the vase. With this “trick” you can usually bring a gladiolus into full bloom, they also last longer and don’t tilt their heads over the front because the bloom was too heavy.

The gladioli in the vase also have a considerable water requirement, you should supply them with fresh water regularly.

If you want to cultivate your gladioli for several years, you should be careful when buying cut flowers – if you cut off too many flowers during the growing season, it could happen that the bulb does not sprout again next summer.

wintering

The onion flowers retreat into their bulbs to hibernate. Important molecules such as starch are stored in this hibernating part, which are available for new shoots in the spring. In this way, a new flower stalk with leaves can grow again in the next season.

In any case, that’s how it works in the warm homeland of the gladioli, but here the bulbs would simply freeze to death in winter and not produce a green stalk in spring. If you want to overwinter gladioli, you must therefore dig up the bulbs and dry them over the winter and store them frost-free. How to proceed:

• The entire gladiolus is carefully lifted out of the ground with the digging fork when its leaves have dried up in autumn.
• Not sooner, the leaves should turn yellow and slowly die off because the plant draws nutrients from them.
• The remains of the foliage are cut off just above the bulb.
• The gladiolus is placed on newspaper until the soil is dry, then you should remove as much soil as possible from the bulbs by hand and by shaking.
• The onions are now dried on newspaper in a warm and well-ventilated place until there is no longer any moisture to be found on the outside.
• Then the bulbs can be moved to paper bags to be stored in over the winter.
• The storage temperature should not exceed 15 degrees.
• Noting which bulbs produce which flower colors on the paper bags can help with next year’s garden design.

Plant and propagate overwintered gladioli

Like store-bought gladiolus bulbs, overwintered bulbs should only be planted in the garden after the last frost. The plant reacts really harshly to frost.

As a special feature, it should be noted that daughter bulbs will have formed on the gladiolus bulbs, the bulbs not only serve as overwintering organs for most bulbous plants, but also as reproductive organs.

These daughter bulbs are meant to be separated from the mother bulb and grow into new, independent gladioli. However, it takes a while before they become really magnificent plants, and the daughter bulbs are also quite small. They can therefore be planted only 5 cm apart in the first year, then 10 cm apart after hibernation in the next season, and so on until they have become “adult” gladioli.

species and varieties

The gladioli belong to the iris family, like the crocus, the freesia and the iris too, they form their own genus Gladiolus in the family of the iris family. In the original homeland from Africa to the Mediterranean countries, a wide variety of natural types of gladioli have developed, between 180 and 260 gladioli species are counted. Many of these natural gladioli species are cultivated and are also available from us, at least via the Internet. Here is a selection if you would like to bring “real”, original gladioli into your garden:

• Abyssinian Gladiolus or Star Gladiolus (Gladiolus callianthus): Beautiful white flower with a dark star in the middle
• Cardinal Gladiolus (Gladiolus cardinalis): Exciting flowers in cardinal red and white
• Flesh Pink Gladiolus (Gladiolus carneus): Really blooms a soft pink with darker red accents
• Ordinary gladiolus (Gladiolus communis): In our mild climates, a hardy “original gladiolus”, until about 1850 the usual ornamental gladiolus
• Blood-red gladiolus (Gladiolus cruentus): Strikingly bright red flowers
• Primrose gladiolus (Gladiolus dalenii): Very long, red inflorescence
• Illyrian gladiolus (Gladiolus illyricus): Delicate gladiolus with light purple flowers
• Opposite gladiolus (Gladiolus oppositiflorus): Flower heads in all pink and orange colors emanating from the shoot on both sides
• Marsh gladiolus (Gladiolus palustris): Native with purple flowers, considered endangered
• Butterfly gladiolus (Gladiolus papilio): double row flowering, yellow flower with red accents and wavy edges
• Monochrome Gladiolus (Gladiolus tristis): White to cream colored flower with purplish-brown shades

The origin of our commonly traded gladioli were numerous wild gladioli that were imported to Europe from South Africa in the 18th century. These species, which have larger flowers than the native gladioli, have been developed by breeders for more than 200 years through repeated crossings into the large-flowered hybrid varieties available today. Among them is the garden gladiolus (Gladiolus × hortulanus).

The Gladiolus × hortulanus hybrids are usually referred to only with “Gladiolus” and their breeding name. Here are some particularly beautifully colored varieties:

• Gladiolus “Amsterdam”: Lavishly lush flowers in brilliant white
• Gladiolus “Nova Lux” gets really nice bright yellow flowers
• G. ‘Peter Pears’ is the famous gladiolus with the huge, salmon-colored flowers
• G. ‘Windsong’: Flowers in a variety of bold colors with contrasting accents in the centre

diseases and pests

The hybrids in particular are repeatedly attacked by blister feet (thrips). Then insecticide use is often recommended. As a preventative measure, the gladioli bulbs should be soaked in an insecticide solution for a few hours before planting.

However, if your gladioli are constantly being attacked by thrips, it may not be the right solution for the health of your plants or the health of your family. In this case, you’d better check the location and posture first. If that doesn’t help, you should use a more resistant, natural gladioli variety.