Although gladioli are among the very robust bulbous plants, they are not completely immune to diseases and pests. We have briefly summarized the most important diseases and pathogens and how to combat them below.
Waterlogging is very harmful to gladioli
Thirpse
The insects, also known as blister feet, feed on the plant juices. The infestation can be recognized by whitish to silvery shimmering suction points. Close inspection reveals tiny, crusty, black droplets of feces. If the infestation is severe or permanent, the leaves and flowers will stun and dry up as a result.
combat
Thrips don't like moisture. Therefore, shower the gladioli thoroughly on a regular basis. It can also be helpful to set up blue glue boards (blue boards).
Don't wait until the leaves are completely dead in the fall to dig up the bulbs, but pull them out when the leaves are still green at the bottom. The thrips are in this area of the plants and can be cut off with the foliage. Dispose of the leaves in the trash as the blistered feet can survive in the warm compost heap.
Thirps in the onions can be recognized by the brown spots and the shrinking of the bulbs. Destroy these bulbs immediately to prevent the pests from spreading. Do not store the tubers too warm, as the harmful insects are very sensitive to cold. Temperatures of around five degrees are ideal.
wet rot or dry rot
In most cases, these diseases are the result of an unsuitable location. If the substrate is too dry, the gladiolus will yellow from the top and die. If it is too humid, wet rot forms at the base of the leaves and the rotten stem falls over.
combat
Destroy diseased plants, including the bulb, during the growing season. No gladioli may be planted in the same place for several years. Therefore, look for a more suitable place for the garden beauties.
Varnish scab (basal rot)
At the base of the leaves there are initially many small, red-brown and raised pustules or black-brown stripes. The leaves become rotten and soft and eventually snap over. Varnish scab also affects the bulbs, showing sunken brown spots with a somewhat raised rim and a varnish-like coating. The small brood nodules are also attacked by the basal rot.
combat
Here, too, it only helps to destroy the plants immediately and not to plant any more gladioli in the same location for the next few years. Chemical means to combat the plant disease are not currently available.
tips
If the gladioli bulbs sprout poorly or if the bulbs shrink into hard mummies in winter storage, the gladioli could be infected with bulb rot. To prevent the disease from spreading, you should store the bulbs properly and check them regularly during the winter. Discard infected bulbs immediately.