The Fiji Connection, Part 2

(Contributed by Bob Rivers-Smith)
Fiji Named Varieties

CULTURAL NOTES

By Jim Purdie

I would like to tell what I do in my garden at this time of the year, which is spring here in Brisbane, OZ.

You people in the northern hemisphere would have to adapt to your own seasons, but here in Brisbane in Australia, I always apply some dolomite in August to raise the pH for one thing, which should be around 6.2 to 6.5 for best results. This allows the plants to take up the elements in the fertilizer at this range. Otherwise they get locked up in the ground when the soil is too acid or too alkaline, and secondly it supplies calcium and magnesium, which are necessary for the health of the plant. I apply it in August because it takes about 6 weeks for the Dolomite to take affect and alter the pH. This allows the soil to be at the right pH when spring arrives in September and for the plant to start to put on its new growth. It can now take up the necessary food out of the ground.

September is the time for us to start pruning. As soon as we see the new growth start to appear, you know it is time to prune to get your new branches for the coming season. I always prune the average bush back about a third and try to open up the bush to allow the sun to penetrate the middle of the plant. Cut off any criss- cross branches, and any old dead wood should be removed. If you have a vigourous growing plant, it can be cut back at least by half. Otherwise it will grow too high, and get too big.

When you see the plant growth starting to get established, that is the time to apply a fertilizer high in nitrogen to promote the new growth. You will not see flowers for at least a couple of months, so it is not much use applying a fertilizer high in potash until you see the buds starting to form. Then you can cut back on the high nitrogen and apply a fertilizer high in potash. Otherwise you will get nice green bushes and not many flowers as you need the potash to promote the blooms.

At the same time, I like to apply a good covering of mulch, which stops weeds, keeps the roots cool in the hot weather, and stops the loss of the water, which is starting to cost an arm and a leg here. I do not know how it is in other places, but the council keeps on putting the charges up on our water we use. I like to use a compost plus sheep manure and cover this with some pine bark fines. When you push the covering back, you will the roots sitting just under the mulch in the cool moist ground, and this is something you must remember. Hibiscus have a lot of surface roots. If you do not have a mulch covering the surface of the ground, these fine surface roots get burned off, and your plant cannot get the same nourishment with less roots, so remember mulch - mulch - mulch.

I mix up a fertilizer that I apply when the plants start to shoot. It consists of 4 x 2 litre ice cream cans of Blood & Bone (I think you call it Hoof & Horn in USA), 2 cans of superphosphate, 1 can of sulphate of potash, 1/2 can of magnesium (epsom salts), and 1/4 can of sulphate of iron. 

I apply a good handful around the drip line of each mature bush, less if your bush is only young. Always water the ground before and after applying any fertilizer, I would not apply this mixture to any pots. It is only suitable for in ground plants.

If you have plants growing in pots then still prune them in the spring, but I think it is best to apply a soluble fertilizer high in nitrogen until the plant re-grows and then change to one high in Potash.

I hope this will be of some assistance to you, but you will have to make adjustments for your own particular area. 

This is what works here for me.

Good growing,
Jim Purdie, Brisbane,

A Golden Anniversary

An Interview with Les Beers
By Gloria White

Being new to hibiscus, I have heard names bounced around by hybridizers and of course come across names of individuals mentioned in books written about the Queen of the Tropics. You will hear the following names frequently in Miami: Harry Goulding, Gordon Howard, Pete Conrad and Joe Ludick. I met Pete Conrad and instantly liked the man. Another name, mentioned because some people here have been lucky enough to meet him, is Les Beers. So what has an Australian writer have to do with this list of notables? Plenty! 

First of all, Les Beers has cultivated an interest in the Queen of the Tropics for close to 50 years. As a boy, he worked in an orchid nursery for spending money. His employer one day came back from Hawaii with several new hibiscus and that was that – love at first sight! Les credits his love for flowers and an interest in plants from his parents. Unfortunately, the orchid growing employer paid slight attention to the hibiscus, so later on when Les started a career path in the nursery business, he was able to have access to these varieties so long neglected. Les felt that if you could show the plant in bloom, it would market itself. The trick we all know now is to get the Queen of the Tropics to show her pretty face when you want her to, and Les was faced with a similar dilemma. Since the blooms last only one day, what was he going to do? Well, the trick was to produce plants with numerous buds.

In 1958, Les and Nancy Beers established Hibiscus Park Nursery but at this point in time there were not enough different cultivars to specialize in hibiscus alone. So they kept stocking the nursery with other plants to keep it going and later were able to import new hibiscus varieties from Ceylon, Fiji, Hawaii, and then Florida. Their nursery had a display room, which held 300 blooms a day during the season. These blooms enabled the Beers to sell their plants and later on they added to their inventory to keep the hibiscus lovers happy.

Les proudly claims credit for the interest for hibiscus in Sydney because of the many visitors that walked through the display room and became enchanted by the Queen of the Tropics. He feels that hibiscus are “on the map here in Australia” because of the hibiscus interest created from his display room. Les further adds that the climate in Sydney is perfect in the autumn for hibiscus.

Les was invested as a Fellow of the Australian Hibiscus Society in 1967. He is a lifetime member of the American Hibiscus Society, which he joined in 1960. He is a noted authority, hybridizer and grower of hibiscus and is often consulted when a book that will contain information on our favorite flower is being written.

The artist Peter Longhurst released “Hibiscus,” a limited edition two- volume set in 1978 and 1979. Les was invited to identify the varieties drawn in the volumes and write the text for the 250 copies released for these two volumes. Copies of these editions exist in private collections and some people have been lucky enough to find copies in specialty bookshops.

In 1985, Les collaborated with another noted hybridizer, grower and authority, Jim Howie. Out of this effort, “Growing Hibiscus” was born, which proved its popularity with reprints in 1986 through 1987 and a second edition published in 1990. A third edition was released in 1995. “Growing Hibiscus” is currently out of print, but a fourth edition is under consideration.

Les is also a contributor in the book “Ornamental Trees and Shrubs” by Raymond J. Rowell, his college mentor. Les’ text contributions can be found in “Horticultural Flora of South Eastern Australia” from the Roger Spencer Royal Botanical Gardens in Melbourne; “Encyclopaedia of Australian Gardening” by Bay Books; and the “Gardeners Encyclopaedia of Plants and Flowers” by Readers Digest. Les’ contributions to hibiscus literature lives on in articles found in “The Seed Pod,” the official publication of the American Hibiscus Society, the “Hibiscus Digest,” gardening periodicals, local newspapers, journals, and newsletters for nursery associations and garden clubs. He can be found as a speaker at garden clubs when time permits.

He considers himself a “pollen duster for many years,” but now Les finds the time to pursue his interests in hybridizing. The list of his cvs goes on and on, and many pictures can be found in “Palmer’s Hibiscus in Colour.” Among his best are: Ben Lexcen, Cindy, Crown of Warringah (sport), Enid Lewis (sport), Jay’s Orange, Boondah, Orange Pride, Patricia Noble (sport), Richard Bodnar, Summer Sun, Colombus, Warriewood Gem, Annie Wood, Caroline’s Dream, Dame Joan, Emily, Guy Mitchell (sport), Jason, Kay’s Girl, Jay’s Pink, Alyrah Carol, Chelsea Rose, Jim’s Star, Jay’s Lavender, Fruitsalad, Matty Man, Professor Topp, and Watermelon Wine (sport). Les further states that Emily, Jay’s Orange and Warriewood Gem “perform well under most conditions” and have great commercial value.

If he had to choose a favorite hibiscus, hands down it would be Golden Belle. Les says, that properly grown these blooms are perfect. The fault, of course, is the bush, but he says the bloom seduces you with its magnificent size, color and texture. At one time, Les had over 600 varieties growing in his garden but has culled down cvs to the very best 100. He has dedicated the space in his garden for only his favorites in his quarter acre block.

Les has an enormous interest in native Australian plants and lets you know that they require special attention. Until he came under the spell of the Queen of the Tropics, he considered growing Australian native plants. He would walk through the bush around Sydney admiring the diversity found there. But that was in the days when there was a lot of bush around Sydney. Nowadays, there are only pockets left, but if you know where to look you will find some marvelous plants.

Les offers his best advice to novices. Feel free to ask other growers about their “culture and successes.” Les says they are willing to tell you their secrets if you are willing to listen. “Look around,” he offers, “and see what does well for your area.” “Hibiscus are highly bred, and each one likes different conditions. Learn to read your plant, try different cultures and use the one that best suits you. One is never too old to learn.” When he started out he met Harry Goulding, Ross Gast, Eric Golby, and Norman Brubaker. He says these greats were very free with their knowledge and all you had to do was listen and “put it into practice.”

Les wants you to know that he will never get to the point where he will know all there is to know about hibiscus. He continually dabbles with different grafting methods, fertilizer sprays, and any other technique that might help his plants. Everyday there is something new. In fact, Les says that if those hybridizers could see the “wonderful world of hibiscus” in this golden age, they would be amazed. They would recognize some old cvs like Ross Estey, Surfrider, Golden Belle and Mollie Cummings that will remain favorites for a long time. One more piece of advice from Les: “Keep on trying. Success usually comes after failure. Just learn from your mistakes and watch your plants. They will let you know if you are not doing the right thing.” 

Thank you Les. I think there are many newbies out there in our global community who will thank you for your words of wisdom.

And the mysterious flower genie surveyed the enchanted garden an hour after dawn. In the early morning light, there was a gem so golden it rivaled the sun for color. Heavily textured and wonderful to behold, the mysterious flower genie took this marvel into her hands and gazed transfixed by the golden aura.

From the chronicles of the mysterious flower genie from the peninsula of flowers - Golden Belle.

Profile in Exhibiting the Queen of the Tropics
An Interview with Janice McNatt of Pearland, Texas

By Gloria White

Last November, I was thinking of entering hibiscus blooms in the Miami Chapter of the American Hibiscus Society’s yearly show. I had only six gvs open that day, and so I clerked for the judges to preserve my amateur status for when I had learned a few more hints and had more flowers to show. But I did not go to my first show unarmed. I had met Janice McNatt through the THML, and she freely gave me information on what I needed to know for the show. It was valuable information for a beginner so I chose Janice to help anyone getting ready to try their hand at showing the Queen of the Tropics.

Janice lives in Pearland, Texas, a quiet suburb 25 miles southeast of downtown Houston. Janice has been working in the medical field for over 28 years and now is a surgical technician.

Not living in the tropics, Janice had never seen an exotic hibiscus and like myself had no idea at the range of color, texture and sheer size available in these blooms today.

Until 3 years ago, she had no idea there was a group of people who dedicated their pastime in discussing, growing, hybridizing and showing hibiscus. What she saw available gave her the same reaction I felt when I first saw this new world. She wanted one of each! But first she needed a bigger yard.

In her first year at following the shows, Janice watched and learned the tricks necessary to arm herself with what she needed to know when her time came to prepare blooms. 

She volunteered to help the Lone Star Chapter’s Roz and Pat Merritt in any way possible. In this capacity, Janice learned the names and preparing the blooms, and it was made easy since the Merritt’s come to a show with hundreds of blooms to enter. Janice did not come to the hibiscus shows without showmanship experience due to her past interests in tournament level tennis and showing horses.   

Janice offers this advice to beginners. You start with a perfect bloom, which sometimes is picked the day before and stored in the refrigerator overnight. When the flower is a third of the way open, you pick it leaving enough stem for you to handle it and avoid damaging it. Place the bloom on a dampened (not wet) paper towel, which is folded to look much like a burrito. You can then store several blooms one on top of the other burritos in a ziploc bag to be kept overnight in the vegetable crisper portion of your refrigerator.

These blooms can then be unwrapped and placed in paper cups with the bottom cut out or the paper funnels used when pouring motor oil in your car. This is all done before leaving for the show. 

The blooms take 30-40 minutes to warm enough for you to handle them without damage. After they warm up, little handling is required. You hold the flower by the stem and you scoop it in an upward motion to open it, causing the bloom to lay flat. Always ensure that you do not disturb the sequence of the petals. These are your first entries.

Blooms produced the same day are difficult to open early in the morning and require the warmth of the sun to enable them to open. It is often better to arrive a little later to the show and not force the bloom because this will cause damage to them. 

Enter these blooms later in the show and make sure the flowers lay flat. Janice also suggests not to enter all your blooms at the same time because judges rarely give gold ribbons to all the flowers on a given tray looking for that superior bloom, so it is better to space your entries.

Her final piece of advice is to enter as many blooms as possible as an amateur, even garden varieties, because even though a gv will not make the head table, a gold is a gold. These points count towards the sweepstakes ribbon when they tabulate your sweepstakes numbers.

Janice is now a junior judge where she can learn by working with gifted senior judges and learning what it takes for a flower to be Best of Show. 

Janice is now an open collector and looks forward to exhibiting at the Texas and Louisiana shows. 

We wish you lots of luck Janice, and you kick some calyxes!

As the time came for the mysterious flower genie to display her gems of many colors, she chose a table not of gold or silver because that would detract from their beauty. The genie chose a table of simple wood and laid the gems on rich black velvet to showcase their lovely colors.

The mysterious flower genie had waited for this day to show the world her collection of gems, a treasure worth several kings and queen’s ransoms. Some were priceless, some were without match and many were a joy to behold. Of all the gems that were shown that day, one stood out in the crowd of beauty. 

This gem glowed as a pearl of pink and was beautiful beyond compare.

From the chronicles of the mysterious flower genie from the peninsula of flowers - Oyster Pearl.

Oyster Pearl

Photography by Chris Noble, OZ

HIBISCUS CARE

by Richard Johnson

LOCATION

When you bring your first hibiscus home, like any new member of the family, the first thing to consider is where they will be most comfortable. It might come as a surprise, but where you might feel comfortable, your hibiscus will too - that is in terms of temperature. Hibiscus will thrive with temperatures from 60 to 90 F. Outside of this range they will be stressed. Below 50 F, they will cease to grow and bloom, and freezing temperatures for more than the briefest of time are likely to be fatal. If you live in other than a tropical or subtropical area, you will have to plan accordingly. One of the first decisions will depend upon how frequently and for how long you might risk temperatures that will endanger your hibiscus. If you only have occasional brief periods of cold, you have two choices: in ground plantings or planting in pots that will be exposed to outside conditions except when protecting them from cold. If you live in areas with prolonged severe winters, your hibiscus will have to be grown in pots and a place for them made available during such months. This could be a temperature controlled green house or your own home.

You will also want to find a location with proper sunlight. Species hibiscus and garden varieties will often flourish in full sun. However, many of the cultivated varieties will prefer perhaps just a half day of full sun and some will do fine with as little as just an hour or so of full sun and the rest of the day in filtered sun or light shade. If your summers are extremely hot, more shade is recommended. If you plant your hibiscus in the ground, try to plant them at least 3 to 5 ft from trees or other large shrubs to prevent root competition. One of the advantages to growing hibiscus in pots is that you can move them from one location to another until you find the conditions, which suit them best.

PLANTING OR POTTING

Hibiscus like soils which drain well so that their roots are never soggy wet for any extended period. A means of acquiring this kind of drainage is to mix two parts of heavier soil with one part of coarse sharp sand. (Sharp sand is that which results from rock crushing operations as opposed to river sand, which is round and smooth.) In the case of potted plants, those soil mixes that are made for hanging baskets, normally have built in good drainage. Your new hibiscus will likely arrive in a container of one sort or another and may already be in need of repotting. This is easily determined by either looking for roots coming out of the drainage holes or carefully sliding the plant out of its pot and inspecting the roots. If there is a mass spiraling around the pot at the bottom, it is time to repot. Here you have two options, either trimming the plant to fit the same pot or moving it up to the next larger sized pot. If your plant is already of substantial size and you want to keep it in the same sized pot, remove about 1/3rd of the roots and 1/3rd to ½ of the top branches. It is prudent to sterilize your pruning shears before and after doing each plant in a strong bleach/soap solution or product like Physan to prevent the transfer of disease. Prepare either a new pot of the same size or the old one, which has been thoroughly washed. Used pots, especially if it is suspected they might have previously housed diseased plants, should be sterilized with a solution of Physan or similar – a 20% bleach solution will also do (1 part of Clorox to 4 parts of water). Renew the soil removed with fresh potting mix while placing the plant so that it sets at the original soil level, which should be about an inch below the rim of the pot. If going into a larger pot, select the next bigger size, for example moving from a 3-gallon pot up to a 4- gallon pot. It is important not to over pot, which means that you don’t want the plant to have more planting medium than the roots will be able to make use of in the next growing season. Over potting can lead to root fungus problems especially in cooler weather. If you want your plants to reach maximum size and live permanently in a pot, 7 gallons is about the smallest that will do the job, but as mentioned, work up to that size gradually.

WATERING

Generally speaking hibiscus like to be kept damp but not soggy wet for anything more than the briefest of periods. Normally, it is best to water thoroughly and let the plants absorb the moisture retained by the growing medium until the surface becomes dry. To test this, push the forefinger into the soil. If no moisture is detected within an inch of the surface, it is time to water. The frequency for watering is dependent upon a number of factors including the size of the plant, the amount of medium it is growing in, the ambient temperature, exposure to sun and wind, etc. In very hot weather with plants exposed to considerable sunlight, daily or even twice daily watering may be necessary. During winter months at reduced temperatures, once a week may suffice. Its better to error on the side of too dry than too wet since the former only results in wilted leaves which will quickly return to normal upon watering, while the latter can result in root disease and eventual loss of the plant. The best means of watering is via an automated drip watering system that is set up so that a small amount of water is delivered over a longer period of time, resulting in the media being well saturated to the bottom. Hand watering is fine if done correctly. Just filling up to the rim may not be enough to saturate a quite dry pot, resulting in just the upper level of the soil being moist and encouraging many fine surface roots. One may have to pass over and fill the pots twice or more. This is a simple affair, when watering plants that are in close proximity. One simply waters all in the area and then returns to the first pot and repeats the process. A good test is to water what is considered to be an adequate amount and 15 minutes later carefully slide one plant out of the pot to see if it is saturated to the bottom. Plants that have thoroughly dried out may seem saturated as evidenced by the water flowing out of the drainage holes, when in fact the central mass is still quite dry since water couldn’t be absorbed as rapidly as it escaped around the edges and out the drains holes. If a plant is wilted and dry, water it and it will likely recover. If it is wilted and damp, it may have a root disease preventing the uptake of water and adding more water only increases the problem.

FERTILIZING

To grow and bloom optimally, hibiscus need continual fertilization, although they will survive and bloom under conditions of considerable neglect as well. Fertilizer should be applied to well-watered plants and never those that are bone dry. Generally lighter dosages more frequently are the very best. The easiest means of accomplishing this is through the use of time release fertilizers like Osmocote. Depending upon the formula and the mean temperatures over the duration, some are good for as much as 9 months. However, these fertilizers are only considered desirable where temperatures exceed 60 F. There are other granular fertilizers such as Nitrophospka which are used with good success on hibiscus, but some report that the continual use of this kind of fertilizer results in a crust like build up on the surface of the soil. Liquid fertilizers or those that dissolve in water can be excellent, especially when incorporated into automated watering systems that can deliver a lesser dosage at each watering. Although any fertilizer is better than none, some are more suitable to hibiscus than others. At the bottom of the list are the bloom booster formulas high in phosphorus such as Miracle Grow. The basic essential ingredients contained in fertilizers are nitrogen ”N” (the first letter), phosphorus ”P” (the middle number) and potassium “K” (the last letter) which is abbreviated as NPK. The corresponding numbers indicate the ratio of these ingredients. For example, an NPK formula of 9/6/12 would have phosphorus in the lowest concentration, followed by nitrogen with potassium being the highest in concentration. This represents the ideal formula, i.e., “P” phosphorus in the lowest concentration and “K” phosphate in the highest concentration. An excess of “P” phosphorus tends to build up in the soil and prevents hibiscus from uptaking or utilizing other needed elements. In addition to the above three major elements there are those referred to as minors which are necessary to optimum growth and include: sulfur, magnesium, calcium, iron, chlorine, manganese, boron, zinc, copper, molybdenum. If you cannot find a formula that includes minors, they can be added through supplementals, such as fish emulsion, sea weed extracts, blood and bone meal. Magnesium often not found in sufficient concentration in most fertilizers can be obtained by adding a couple of table spoons of Epson Salts to a pot every month or two. Lastly, for these elements to be accessible to hibiscus, a pH on the just slightly acid side at 6 to 7 is ideal. The more the pH varies from this ideal the less various elements provided by fertilizers will be available to them and the plants suffer accordingly. The environment in which the complete soil mix and nutritional elements are contained is equally as important. To maintain it in the best condition, a mulch on the surface is highly recommended. It serves to buffer temperature and humidity and keep weeds at a minimum while generally helping to maintain an optimal soil environment. If your hibiscus are in pots, the pot itself can be isolated from direct contact with the sun by placing it inside of another pot to help prevent overheating. Alternatively, the pot can also be placed amongst shrubbery or itself planted into the ground for the warm season in a fashion that it can be easily removed to a protected location in the event temperatures may reach freezing as the seasons turn.

PRUNING

Hibiscus placed in a suitable area, with proper growing media, water and fertilizer will grow and flourish. However, if optimal bush shape and maximum bloom output are desired, pruning is essential for most tropical hibiscus. A small plant received in a 3” pot, should have its one or two vertical stems pinched at the tip when there are at least 4 leaves or nodes on the branch. This is accomplished by snipping off the growing end with the thumbnail by pressing it against the forefinger and is referred to as pinching, pinch pruning, tip pruning, etc. Ideally this will result is the formation of two or more branches on each stem. When these have 3 or 4 leaves, pinch again. A third pinch is only necessary if the previous pinching didn’t result in the number of branches desired to form a nice shaped bush. Remember, hibiscus generally produce new flowers at the tips of each branch, so more branches not only provides for a more beautiful bush but many more blooms as well. The price one pays is that blooming is delayed while each new branch develops. Larger bushes can also benefit from pruning to both improve their shape and increase vigor. The severing of the branch sets off a series of physiological processes, including the production of auxins and growth stimulants. Hence, pruning can revitalize an older bush, which has slowed its growth. If one is reluctant to prune due to the loss of flowers, prune sequentially. This simply means to trim the central branch first, and as it reaches bloom maturity progressively prune the lateral branches. Remember the branch pruned first will be the tallest when the pruning process is completed, hence the reason for commencing with the central branch first. There is also a technique to pruning. As the most likely place for the new branch to grow from is the leaf or two just below the cut, one can pretty much choose where they want the new branch to come from. Generally it is best to cut about 1/4” above an outward facing leaf. The cut should be made diagonally so that water will tend to flow off the wound and reduce the likelihood of infection. Although often unnecessary, pruning tar can be applied to the newly pruned branch. If one has a bush that has grown ugly, it can be reshaped from scratch. First, decide at what height you want the first branches to appear and prune just above the leaf at that point. If there are no leaves on the plant below the point you want to prune, there is a small chance there are no live growth points, in which case pruning at this point might result in the destruction of your plant. There is a way to solve this. Make a test prune somewhat higher above the lowest leaf. In a few weeks new leaves will start to appear where there are live nodes. It is then safe to prune just above one of these new growth points. This method also provides you greater flexibility is choosing just where you want the new growth to come from. As those branches grow, prune them until the desired bushiness is derived. Hibiscus can be pruned most any time of the year, so schedule pruning to your seasons and needs. Generally, it is best to prune in early spring. This will produce maximum blooms 6 to 8 weeks later.

INSECTS & DISEASE

The strongest defense against insects and disease, are healthy well-grown plants with a minimum of stressful conditions. However, there will come a time when intervention of one sort or another is necessary. 

With regard to insects, the first means of defense is biological, i.e., development of a healthy and diverse garden, which keeps pests in control by natural predators. For instance lady bugs and especially their voracious larval stages devour aphids and many other hazardous insects. Accordingly, when additional intervention is required, the welfare of these natural predators as well as other non-intrusive inhabitants of the garden should be taken into consideration. 

The second level of defense consists of mechanical means of extraction or eradication. White ice cream containers with one inch of water in the bottom to which has been added a couple of squirts of dishwashing detergent, make excellent traps for pollen beetles which damage flowers. They are attracted to the white, like a large white flower, and when flying into the soapy solution, quickly drown. Note, without the detergent they will likely escape and your traps become a nesting ground for mosquitoes. Sticky tape can be used to collect other flying insects like white fly. Copper tape builds up an electrolytic barrier across which snails and slugs will not pass. Containers with a small amount of beer, will attract and drown slugs. Predatory snails are sold for the control of slugs. Wood ashes and diatomaceous earth provide barriers across which ants, slugs and other pests will not cross. Also, included in this category is water either sprayed at normal or high pressure to areas of infestation. Simply spraying a plant down with a hose end nozzle can be quite effective for aphids and to a lesser degree for white flies. There are special pressurized water wands for this purpose that will actually remove scale. With minimal imagination one can be fashioned. Remember the undersurfaces of leaves are especially important areas of insect infestation so concentrate here with any contraceptive measures. 

The third level of defense would include non- or low-toxicity chemical agents. There are a number of brands names that specialize in such products, e.g., Safers, which take various forms such as insecticidal soap, fine oils, etc. Dish soap applied at a teaspoon per gallon will rid a plant of many pests. Fine horticultural oils sprayed over the entire surface of a plant will smother most attached or sucking insects and in some case their eggs as well. Orthene Volck oil is such a product. These products should be applied to well watered plants early morning or late afternoon to avoid burning the leaves of the plant being treated.

The fourth level of defense is to employ granular systemic insecticides such as disystan or marathon. Although highly toxic, the chemical solutions pass into the plant through the root system to permeate the tissues, which although harmless to the plant itself, becomes fatal to sucking insects. These agents generally do not enter the bud itself in sufficient concentration to protect the flower from the damaging activities of insects. Although potent, as the active agents are contained inside the plant, beneficial insects are for the most part unaffected.

The last line of defense is potent specialized chemicals. If possible, to restrict the damaging side effects (beneficial insects, for example) only spot treat areas of heavy infestation. A particularly potent combination is a triple dosage of imidacloprid found in products like Confidor into which has been added Orthene Volck oil and applied by a hand sprayer. Spot sprayed once or twice a week for several weeks, it has been found to eradicate erinose mite and snow scale, two of the most stubborn problems. This is a generalized treatment interval, but for specific information check the life cycles of the insect or mite in question, especially the gestation period of eggs which might not be killed by the treatment and spray again just after that period. Mites are often little affected by normal insecticides, hence, special miticidal products are recommended and again used with a fine oil like Orthene Volck oil is even more effective.

There are number of fungal or bacterial disease which can damage hibiscus. In many cases these coexist at tolerable levels doing little damage to the plants, and in at least on case, e.g., microrizal fungi, are considered beneficial and even necessary to a plants health. When any of these disease agents get out of control, measures may be necessary. Again prevention is the first line of defense. Hard wood bark is considered to have anti fungal qualities but must be used at a threshold percentage in the mix to be effective. In the soil, root fungus can be a killer. As this group of fungi grow best at the cooler temperatures of 40 to 60 F (5 – 15 C) and in wet soil conditions, the preventative measure of avoiding these conditions is the first recommendation. A household remedy that works in many cases is the use of a 10 or 20% bleach solution. Physan is considered multi action: anti viral, anti fungal and anti bacterial and is particularly effective in helping maintain sterile pots, cutting tools, etc.

COMMON PROBLEMS

Yellowing Leaves: Tropical hibiscus are evergreen plants meaning that they always have green leaves which eventually become old, turn yellow and are replaced by new leaves. This is a normal process. However, yellow leaves in excess can be an indicator of problems. The first thing to suspect is stress. Hibiscus like each day to be the same, meaning they appreciate static conditions with minimal fluctuation. If there have been temperature or moisture extremes, hibiscus will respond by more yellow leaves than normal. It could be related to events, i.e., the moving of a plant from one location to another or their having been treated chemically. It could be due to insect or mite infestations, so close inspection of the plants is in order. There are a dozen or more reasons why an excess of yellowing leaves might occur, so you need to become a hibiscus Sherlock Holmes and deduce the most likely cause pending an evaluation of all the factors.

Bud Drop: A small percentage of bud drop seems to be somewhat normal, and some varieties are more prone to bud drop than others. At higher temperatures certain varieties may produce buds but few if any develop to maturity, but these plants return back to normal as the weather cools. In other varieties, they simply cease to produce buds at all at higher temperatures. Some are sensitive to under or over fertilizing and respond by dropped buds. There are cases when bud drop is the result of insects, either gall midge or thrips. In the case of gall midge, cut the dropped bloom in half with a sharp cutter and closely observe the cut surfaces. If you see something jumping, almost like liquid particles popping off the top of a carbonated drink, you’re probably seeing the gall midge larvae and have likely found your problem. Thrips will lay their eggs in buds, but this usually results in bud drop at an earlier age. Fungus can attack buds, in which case they tend to putrefy. Again observations and deduction are your best weapons.

LISTEN TO YOUR HIBISCUS

The above are the basics of hibiscus care, but the last and one of the most important aspects, is to frequently visit and inspect your plants. They definitely can communicate, and it is up to you to understand their language. When the leaves droop, they are telling you something is wrong: either not enough water indicated by drooping leaves and a dry potting media or root fungus preventing the roots from functioning and getting water to the leaves indicated by a moist pot and drooping leaves. 

It’s up to you to hear what your plants are telling you, and this is part of the reward of growing hibiscus, for when you listen they thrive and produce their incredibly magnificent blooms, making the both of you happy to be alive.    

United States Hibiscus Society Publications

American Hibiscus Society – The Seed Pod

Lone Star Chapter  (AHS) (Houston)  – The Petaloid

Acadiana Chapter (AHS) (Lafayette, Louisiana – “Hooked on Hibiscus”

Baton Rouge Chapter (AHS) – “Hibiscus Gleanings”

Space City Chapter (Pasadena, Texas) - “The Growing Pains”

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© 2004 International Hibiscus Society