Flower bulbs

Caring for gladioli — worth knowing for a long bloom

Blooming gladioli delight in late summer and autumn with characteristic blossoms at a stately height. Above all, the beautiful and long bloom speaks for the popular flowers. The plant genus belongs to the iris family (Iridaceae). The upright growing varieties can grow up to 1.50 meters high. It is important that you dig up the tubers before the first night frosts and store them in a protected place until next spring. Gladioli can easily be overwintered.

Useful information Location Planting time Planting Watering Fertilizing Digging up/overwintering Species Pests & diseases FAQ

Matching products – buy gladioli

Interesting facts about gladioli

Botanical name: Gladiolus hybrid
Other names: sword flower, garden gladiolus
Use: bedding plant, border plant, cut flower
Origin: South Africa
Planting time

April to May
Flowering period: July to October
Flower colours: white, yellow, orange, pink, red, purple, blue, two-tone
Special features: Caution! Gladioli are not hardy, but can easily be overwintered indoors frost-free and are therefore perennial. In the summer they need little care and attention. They are ideal for the garden or large containers on the balcony.

In which location do gladioli feel most comfortable?

The popular garden flowers prefer a sunny location that is as sheltered from the wind as possible. A permeable, humus-rich and moist soil is important, without standing water. If the soil conditions are not optimal, better drainage can be provided with sand or a light soil can be improved with high-quality planting soil. The classics can also be cultivated in large pots and can beautify the balcony or terrace. It is important here that the vessel has a water drainage hole and thus waterlogging is excluded.

DIY: Gladiolus bulbs are also a good way for children to make their first experiences with plants. The first green is visible just a few weeks after planting and with little care, colorful flowers appear in summer.

When is the right time to plant Gladiolus?

Wait until the last frosts are over and the bed can be worked well before planting. Starting too early is more of a disadvantage, as loose soil and the appropriate warmth are necessary for root formation. Depending on the weather and region, the best planting time is from mid-April to mid-May. If planted too late, it will be more difficult for the plants to establish themselves at the site and the flowers will be smaller. Basically, the planting time depends on the type. There are early-flowering, mid-flowering and late-flowering species.

What is the best way to plant the tubers in the garden in spring?

The 7 steps of planting:

  • Loosen the soil well and remove all weeds.
  • Dig a planting hole with a bulb planter or hand spade.
  • Put good quality potting soil in the planting hole.
  • Optionally, you can activate and support soil activity with organic flower bulb power. Put this soil activator in the planting hole before planting or sprinkle it on the surface and work it in. The use of organic flower bulb power also keeps voles away.
  • Now the tubers are planted in the planting hole. Make sure there is a bottom and top. Last year’s stalk can still be seen on the upper side and small eyes (shoots) are partially visible.
  • Cover the tubers loosely with the humus-rich garden soil and press them down lightly.
  • Watering after planting is not absolutely necessary. Tip: The dreamlike flower swords are ideal in combination with perennials, grasses or annual bedding plants. It is also ideal if you don’t just plant the same varieties, but different colors or variants with different flowering times. In this way you can delay the full blooms in the garden for weeks.

    The basic rule for planting depth is:

    Make sure that the bulbs are two to three times as high. Note that if you plant too deep, budding will be poorer and delayed.

    The basic rule for planting distances is:

    The planting distance varies depending on the height of the plant, with tall varieties you can plant at a distance of twenty centimeters and with dwarf gladioli ten centimeters. Whether you put out the summer flowers in rows or in groups depends on the situation in the garden and your preferences. A place along a fence has the advantage that it is easier to tie up in strong winds. The exact planting distances are noted on the packaging.

    How do I water my sword flowers properly?

    Due to their origin, Gladiolus are easy to care for and only rarely require additional watering. Whether you need to water depends mainly on rainfall, soil type and temperature. Watering immediately after planting can help create a ground connection between the storage organ and the soil. As soon as the young shoots are visible, watering is only necessary in dry locations and in phases without precipitation. Flower bulbs in a pot are watered depending on the location. It is important that waterlogging is avoided.

    How do I properly fertilize my gladioli bulbs?

    Fertilizing with organic flower bulb power is recommended immediately after planting. The organic NPK fertilizer promotes soil life and microorganisms. In addition, it prevents voles and other unwanted rodents from eating and damaging the tubers. Alternatively, natural fertilizer can be used during sprouting. Sufficient nutrients are important for large flowers, stable stalks and the formation of small corms. When sword flowers suffer from a lack of fertilizer, the flowers are smaller.

    How are tubers dug up and overwintered?

    Most of the iris family are not hardy. Therefore, you need to dig up the storage organs before the first frost. To do this, use a digging fork and loosen the soil around the root ball. Whether you cut the green or not is up to you. Roughly remove the adhering soil from the bed so that the storage organs can be stored dry. Overwintering in a cool and frost-free place is ideal. Well suited are unheated basement rooms, preferably without daylight. To storeStore Gladiolus in wooden boxes with newspaper on the bottom and covering the bulbs at a maximum temperature between 10 to 12 degrees Celsius. To prevent drying out, storage can take place in a sand-soil mixture. All winter long you do not have to take anything into account and take care of it. Make sure the room is neither too warm nor too humid.
    Knowledge fact: It is important for the tubers to mature that they are only dug up late in autumn. In good conditions, the storage organs develop well in late summer in the garden, overwinter well indoors and can be in the garden again year after year.

    What types of gladioli are there?

    Most of the magnificent gladioli are hybrids. Breeding has resulted in colorful varieties with interesting flowers. The individual blossoms are true works of art, some with fringed or flamed blossoms.

    A special feature in the range is the species known as star gladiolus. Gladiolus callianthus surprises with a fine fragrance and is an enrichment in every garden. Butterflies in particular are attracted to the variant known as scented gladiolus. In winter, this variant also has to hibernate indoors.

    What pests and diseases can gladioli get?

    Basically, the popular cut flowers and garden beauties are resistant to diseases and pests. The following problems can arise:

    wet rot or dry rot

    If the location is too dry or if the soil has been moist for a long time, the gladiolus may yellow and die from the top. Only improved conditions help.


    Especially in very dry phases, infestation by harmful insects can occur. The insects, also known as blister feet, suck on the leaves and the infestation becomes visible through white to silvery shimmering sucking spots. Heavy infestations result in stunted leaves and dried flowers. Improve the conditions and strengthen at the first signs with organic herbal treatment.


    FAQ — Frequently asked questions about gladioli

    Why aren’t my gladioli blooming?

    Missing or sparse flowering can be the result of a lack of fertilizer. A shady location can also be the reason for a lack of flowering. If the soil is too moist, the sprouting gets stuck and the flowers are stunted. With improved conditions, sword flowers will bloom next year.

    Can gladioli be planted in the same spot for several years in a row?

    An annual change in the planting of tubers and bulbs is ideal. However, it is also possible to plant in the same spot for many years. Sufficient soil preparation and fertilization are important. For example, a layer of compost in autumn can help to improve the soil structure significantly.

    When do I have to prune gladioli?

    Leave the green on the bulb as long as possible. Similar to dahlias, the leaf is used to generate energy for the storage organ. The longer the tuber develops and matures, the stronger the budding in the next year. If you would like to cut the flowers for the vase, this is of course possible. Make sure that the leaf on the tuber is spared and only the flower stalk is cut off.

    Are there hardy gladioli?

    The small-flowered varieties are usually a little more tolerant of low temperatures than the large-flowered hybrids. In the trade it is mainly Gladiolus communis, which is described as frost-resistant. Covering with brushwood or leaves is still recommended.

    What is the difference between onion and tuber?

    Onions consist of different layers that lie on top of each other and cannot be divided. The inflorescences of onions are already fully developed and onions have no visible growing points. Important flower bulbs are: tulips, hyacinths, daffodils, grape hyacinths and snowdrops. Gladioli belong to the bulbs. Tubers consist of one piece, have several eyes (vegetation points) and are therefore easy to divide. Flower formation is still taking place in the tubers. Well-known representatives of this group are dahlias or tuberous begonias. Both are not hardy, see chapter Overwintering gladioli.

    How can gladioli be propagated?

    As with onions, gladiolus bulbs produce small brooding bulbs. These take 1 to 2 years to produce flower stalks.