The gardenia is naturally very easy to care for and undemanding. However, if there are increasing maintenance errors, create a good basis for different plant diseases.© ponsatorn - Fotolia.com
As long as the gardener meets the demands of gardenia (Gardenia jasminoides), the plant thanks the plant with abundant growth and abundant flowering. But what about care errors? If the plant no longer looks healthy or does not flower as abundantly as usual, then something is wrong. It is important to act quickly, because weakened plants are a welcome starting point for fungi and pests.
The following are increasingly observed in gardenias:
- Wrong mildew
- spider mites
Overview of diseases and pests
❍ Downy mildew - the receipt for wet feet
Downy mildew arises in an environment that gardenia does not like and cannot tolerate - namely a soil that is too wet. If the moisture cannot drain off sufficiently, the plant's greatest enemy is waterlogging. Downy mildew can be seen on the leaves. There is a white, powdery and flour-like coating. Later the leaves wither and fall off.
Downy mildew is clearly visible to the naked eye and requires quick action. All infected parts of the plant must be removed as soon as possible. Since the floor is probably far too wet and heavy, repotting immediately is advisable. The old soil must be completely removed from the root ball. The new substrate should be made more permeable with sand or gravel.
" Tip: Gardenia infested with mildew should not be poured from above, so that the fungal spores do not spread into the soil.
❍ Aphids - uninvited guests with a good appetite
Aphids rarely stop at houseplants and can also infect gardenia from time to time. The risk is particularly high in summer. If you regularly check your plants, you won't miss the little green pests.
Aphids can be controlled quite reliably without the use of chemicals. Lighter infestations can be countered with a cold shower. The root ball must be placed in a sealed plastic bag so that the pests cannot get to the ground and the substrate does not become too wet and the build-up of waterlogging favors. A lasting effect can also be achieved by spraying the gardenia with a brew of nettle leaves, onions or garlic. The treatment must be repeated several times for long-term success.
" Attention: Only the leaves and buds of the gardenia can be sprayed, but not the flowers.
❍ Spider mites - when the gardenia starts to sweat
Spider mites prefer dryness and warmth. If the air humidity is permanently too low, an infestation can occur. The infestation with spider mites is particularly evident from the yellowing of the leaves. If you look at the underside of the leaves, you will probably see the small, red arachnids.
Spider mites are harder to get rid of than aphids. If the infestation was detected early, it can help to spray with soapy water or a plant brew mentioned. In the case of advanced infestation, chemical agents cannot be avoided. The plant should also be isolated so that the infection does not spread to the surrounding plants.
Avoid maintenance errors - this is important
Gardenias are quite demanding in terms of their location, soil and watering behavior. If the plant lover cannot do it justice, this weakens the plants and sooner or later the first signs of the disease become noticeable.
- Waterlogging poses a great danger. If the water cannot drain and starts to build up in the planter, it attacks the roots. If the roots start to rot, the plant can usually no longer be helped.
- If the gardenia gets too little nutrients, this is accompanied by yellowing of the leaves. If the leaves are yellow and the leaf veins are clearly green, the plant suffers from a magnesium deficiency and urgently needs appropriate fertilization.
- Location problems with dropping leaves and buds can also be acknowledged. If the problem is resolved, the plant will usually recover quickly and form new leaves and flowers.
The gardenia is blooming rotten, what should be done?
If the hoped-for flower does not appear, there is most likely also a maintenance error behind it. Gardenias need constant high temperatures and air humidity to form flowers.
" Tip: The buds may be sprayed with water during flower formation. The flowers must no longer come into contact with the spray mist.
Even in winter, the plants must not be too cool. A moist, warm climate is ideal for stimulating the flower formation. Therefore, the plant can be overwintered very well on the windowsill in the kitchen. The temperatures here are pleasant and the steam generated by the cooking is remarkably good for the tropical plant.