Pests Of Hibiscus
The organic philosophy
Various organic processes, including natural farming, biodynamics and permaculture, not only aim to lessen and preferably do away with toxic chemicals that are detrimental for the health of plants, animals (including humans) and the planet, but also to comprehend the nature’s own processes so that we may participate in them and not, in any way, cause a hindrance for them.
In other words, organic philosophy is basically an alteration in the way we usually think. Rather than thinking of large scale monoculture, we need to consider them as an element of the natural system by keeping the insects that harm plants in control by using predators, and not synthetic chemicals. At the same time, we should not expect all edible and ornamental plants to be free from blemishes, because nature is not impelled by glossy advertisements. Therefore, we should always think of the different ways that the plants survive by without human intrusion.
- Food for resistance
- Feeding your hibiscus with superior quality and balanced compost will help the plant to thrive as well as resist diseases. On the contrary, providing chemical fertilizers to the plants can make them have too much, which can, in turn, kill all types of micro organisms. For instance, providing too much to edible plants may result in nitrites that promote cancer. Similarly, any imbalance due to excessive feeding using chemical fertilizers may lead to diseases and infestation by pests. Using nitrogenous fertilizers is especially harmful, as these encourage speedy soft growth, which draws sucking insects.
The situation is very similar to the mammalian predators that choose to attack the weakest in a herd. Insects too infest or invade the weakest plants. In case you are not certain if particular compost is resistance food, you may undertake an experiment by employing organic as well as inorganic fertilizers at the same time for two different lots of cabbage or carrots. Provide one of these lots with the best quality compost you can avail, while providing the other lot with a nitrogenous fertilizer, for instance sulfate of ammonia. You will be surprised to note that the pests will consume the nitrogenous fertilizer more quickly.
Stress is another comparison. When humans are under stress, they become susceptible to common colds, flu and other contagious diseases. Similarly the plants also become vulnerable to various diseases when they are in stress.
It is always advisable to use a soil containing high levels of organic substances, as it provides necessary nutrients. At the same time, it also slows down occurrence of various diseases caused by fungi and bacteria, for instance phytophthora, as this kind of soil promotes antibiotic actions of mycorrhizal fungi. Most importantly, the texture of organic-rich soil is an excellent growing medium for hibiscus, because it provides the plants with the most essential air-filled porosity. Your favourite hibiscus will grow excellently and resist all onslaughts from pests and avoid harm provided they are fed properly.
- Stability in the garden
- While gardening, you should aim to give the most conducive conditions to all the plants. Try to match each of the plants with the best condition for them at all levels, right from the creepers that cover the ground to medium height shrubs to the large plants that form a canopy in your garden.
Having a stable garden means that it will not have any plant that is extremely difficult or almost impossible to grow in the climate and conditions prevailing in your region. It should also not contain a large number of same types of plants that are different from the remaining plants in your garden. Besides the processes involved in planting as well as transplanting the plants, a stable garden is neither dug or hoed regularly. Instead, you should allow the different layers of soil to accumulate in a manner akin to the floor of a rainforest. In fact, layering and mulching replicate the nature’s processes.
Moreover, when we talk about a stable garden we refer to a garden when one practices natural pest control methods and the garden is always a steady, but manageable pest supply, which serves as natural foods for an unvarying number of predators. A perfect ecosystem has place for both. In fact, all insects are not harmful. There are a number of predators that never harm any plant, while there are others who will increase their numbers all the time.
- Companion planting for insect control
- A stable garden should also comprise companion planting to control pests. Although companion planting is essential, it does not solve all your problems related to pest control. Solitarily, companion gardening is not all that effective in eliminating the harmful pests from your garden, but it does contribute to the stability and diversity of the garden. In fact, companion gardening can help to fend off or even draw specific pests by releasing various different aromas, making use of different soil levels and inhabiting special spaces in specific combinations in your garden. For instance, coriander, feverfew, hyssop and nasturtium are some of the plants that draw aphids and are excellent as companion plants for hibiscus.
There are various types of hibiscus pests. While some are bad, others are worse. In fact, larvae of different garden butterflies can destroy hibiscus leaves by eating them up. However, the damage caused by them is mainly visual. These larval grubs actually thrive on the foliage of soft-timbered trees and shrubs, while there are some others that generally lay eggs at the same time. Therefore, in case you come across one such grub, be sure that there will be plenty of them around. Visit your garden early in the morning, you may find many such larval grubs and if you find them in their early stage of development, you may also catch the entire batch and destroy it.
- Chewing insects
- You may also look for beetles in your garden. Except for the bronze beetles (Eucolaspis brunnea), which are akin to flea and jump very fast and are difficult to catch, you can easily get rid of most beetles by hand provided you don’t disturb the bush before catching them.
Although snails and slugs are insatiable chewers, they only pose a hazard for the new leaves, especially those appearing on young plants. Having lots of birds in your garden is the best means to control snails and slugs. Apart from these, bright green katydids – flying bugs that camouflage themselves well, and grasshoppers are other chewing pests that may damage hibiscus. Other chewers include stick insects, but they usually don’t disturb hibiscus plants. The female katydids are expert in disguising themselves on the bush and their eggs fall on the ground, emerging as nymphs during spring. These nymphs climb up the stems and invade new leaves. You can thwart them from reaching the new leaves by covering some portion of the tree trunks with grease as a band. Using Vaseline may prove to be effective in preventing them from reaching the leaves.
- Sucking insects
- Usually, sucking pests are less noticeable. While you can easily spot Nezara viridula, a green-hued vegetable bug, and its immature variety having multicoloured mosaic back, majority of the sucking insects in your garden are much smaller and, hence, less conspicuous. While scale insects measure just about 1 mm (1/16 of an inch) in length, spider mites are of the size of pinpricks and can swathe the underside of hibiscus leaves. In addition to the common aphid, mealy bugs, a powdery pest, are also a major threat for hibiscus. Whenever you visit your garden you need to be watchful to locate these bugs, if any. You can detect their presence from the white spots (called chlorosis) caused by spider mites, sooty moulds caused by aphids and mealy bugs and misshapen buds due to aphid invasion.
There are various ways to get rid of these pests and spraying insecticidal should always be the last option among these. At first you should try to remove them by hand and if that is not enough, wash them out using a powerful hose. However, squashing the bugs by hand or using a strong-pressured hose will not be very effective, as these pets cover themselves as well as the adjuring surface with a wax-like substance, preventing them from being dislodged easily. Therefore, it is suggested that you try using a paintbrush to apply a solution prepared with equal amounts of water and methylated spirits. This kind of spot application is environmentally safer compared to spraying harmful chemicals to get rid of the bugs.
Thrips are another type of sucking insects that are difficult to put off, because they move very rapidly. They cause maximum damage to hibiscus when the weather conditions are dry, but generally do not create any problem in damp areas. Hosing the plants often as well as misting them can help to get rid of these bugs. Infestations by whitefly are a common occurrence, especially in warm glasshouses. However, usually these bugs do not pose any problem for home gardeners provided the hibiscus plants are grown in a well ventilated condition.
- Other pests
- Apart from the pests discussed above, gall midge is a major problem for hibiscus growers. This bug lays eggs inside the flower buds, and these are subsequently damaged by the larvae. Eventually the buds drop on the ground and this often indicates that the bug is present in your garden. To eliminate this pest you need to pick all the affected buds, including those that have dropped on the ground and have started molding. At the same time, apply orthene to the buds and foliage and add diazinon to the earth on a regular basis.
The metallic green Japanese beetle (scientific name Popillia japonica) present in fond of flowers and buds is another major problem for gardeners. You can deal with the adult beetles by spraying rotenone, malathion, methoxychlor or sevin.
There are a number of other pests that gardeners have to deal with and the hibiscus beetle (scientific name Macroura concolor) is perhaps the most dreaded plague that affects hibiscus plants. Fortunately, this bug is confined to Queensland, Australia.
- Natural controls and non-toxic pesticides
- It is advisable that you always adopt natural controls to deal with most of the pests mentioned above. Hoverflies are one of the natural predators that possess the ability to consume aphids in large numbers. They can also consume mites as well as scale insects like the completely carnivorous praying mantis that consume aphids, beetles, caterpillars, leaf hoppers and at times even spiders and moths. Spiders, on the other hand, consume flies that thrive on whiteflies and moths. Even the ladybug, which is known to be always beneficial, is a vital natural predator. In fact, one should always promote ladybugs everywhere. Soon after hatching, the larvae of ladybugs immediately begin to consume aphids, woolly aphids, mealy bugs, thrips as well as other insects that suck plant sap. Ladybugs grow up benefitting gardeners by cleansing all such menaces.
Using non-toxic sprays is not as harmful as using chemical sprays. Although they do not cause any harm to humans, you should always be careful while using non-toxic sprays because their indiscriminate use will not only kill the pests you intend to eliminate, but also their predators. The non-toxic formulae discussed here are effective for a brief period and disintegrate fast and, hence, ought to be used promptly. For instance, pyrethrum is one non-toxic insecticide that can be used for a variety of purposes. You can prepare your own pyrethrum using Tanacetum cinerariifolium, or purchase the ready-made insecticide from stores selling gardening products. Garlic spray is another effective non-toxic insecticide. You can prepare this by soaking about 3 ounce (85 grams) unpeeled garlic in any good mineral oil for roughly 24 hours. Now take 1 pint (600 ml) of water containing a liquefied bar soap and add it to the garlic preparation. Subsequently, filter the liquid and water it down by five times and spray the plants affected by insects. However, this garlic formula is not a contact spray and need to be eaten by insects for it to work effectively. When insects like bugs, stink, as well as the mosaic-backed vegetable insect consume this spray, they will be killed instantaneously.
Chili sprays are also an excellent natural and non-toxic means to get your garden rid of certain insects, especially loopers and caterpillars, which are put off by sprinkling cayenne pepper powder. Prepare the formula using one cup (250 ml) freshly pulped chili pepper and mix it with half a cup of dried chili and one cup of water. Similarly, using buttermilk spray will help to keep mites at bay if you apply it to the leaves’ underside once in two days. Prepare the spray by blending one-fourth cup of buttermilk with two cup (500 ml) flour and one gallon (5 litres) water. At the same time, you may also use onion spray for eliminating aphids, scale, mites and thrips. Prepare the spray by boiling 1 kg (2.5 pound) chopped whole onions in half litre (3/4 pint) water. Strain the resultant solution and dilute it 20 times by adding enough water. Then spray the solution to keep your hibiscus free from thrips, scale, mites and aphids.
There are a number of other non-toxic substances that you can use to control pests in your garden. For instance, you may apply the dry wood ash from your fireplace to keep earwigs, which damage hibiscus leaves by consuming them, as well as katydids and grasshoppers at bay. In addition, a section of gardeners also suggest using any watered down antiseptic solution in the form of an effective general insecticidal. Try this if you can.
Traps are also an excellent natural way to deal with predators. For instance you may cut a small piece of cardboard, preferably white or yellow and approximately of your hand’s size, and apply a coat of Vaseline on it. Next, tie the cardboard to a branch of the hibiscus or fix it to a stake. It will attract several insects, especially those that fly at night, as these pests are drawn to light, and get stuck to the Vaseline fast. In fact, this device will also help you to gauge the population of insects in your locality. You can also make a different trap to especially catch aphids using a solution of sugar and yeast.
Spreading diluted yeast around your garden in small amounts is yet another non-toxic means to control pests. It will draw predators like lacewings and hoverflies that consume aphids for survival.
History of hibiscus
Outdoor cultivation of hibiscus
Growing hibiscus in containers
Propagation of hibiscus
Pruning and maintenance of hibiscus
Diseases of hibiscus