14. Questions and Answers
An easy way to diagnose your problems!We have endeavoured to supply answers to the questions most asked abouthibiscus that we receive each year. Some specific problems cannot be solvedwithout inspection of the plant, whilst others are readily rectified.
Learn to observe yourplants - accurate descriptions of problems assist in recommending treatment,many symptoms being similar but requiring different treatment. We sincerelyhope that our answers lead to better hibiscus!
Pests andDiseases
Q. My plants are not flowering.Although they look very healthy, there is no sign of any buds!
A. Hibiscus require full sun toproducegood flowering wood, so the plantcould be growing in a shady position, otherwise the plant has been infestedwith tip‑borer. This very small borer attacks the growing tips in spring,automatically tip‑pruning the plant. The loss of the growing tip at thistime prevents the green wood in maturing into flowering wood. Spray regularlyduring spring with Endosulfan or Carbaryl.
Q. Although I have been keeping it moist, my plant is wilting.A. Sounds as though you may have keptit too moist, and it is suffering from either root‑rot or collar‑rot.It is best to discard the plant and improve the drainage in that position, andreplace the soil before replanting.
Q. My plant suddenly turned yellow andlost all its leaves.A. This plant has received a severeshock possibly caused by spraying with either Malathion or Lannate or othersystemic insecticide. Spraying on a very hot day, using too much white oil,overfertilising or not watering the fertiliser in properly after applicationare possible causes. Cultivating too close to the main stem, borer infestationor collar‑rot may also be to blame.
Q. One large branch on my plant hassuddenly died.A. Your plant has borer. Cut out theaffected parts immediately, and next pruning time, cut the plant back very hardand drench the stems with either Chlordane or Dieldrin.
Q.How do I get rid of the Hibiscus Beetle?
A. The problem with this beetle isthat it penetrates the buds before they open, making it safe from sprayingmaterials. The general rule is to apply a follow‑up spray about two dayslater. The beetle becomes immune to spray very quickly, therefore rotation ofsprays is necessary. Use Endosulfan, Carbaryl, Diazinon, Mesurol (Methiocarb)alternately for best results and Dieldrin and Lebaycid occasionally. A suitablewetting agent aids in applying the spray to give better coverage. Both Diazinonand Mesurol will cause slight discolouration in blooms for several days afterspraying. Spray when the first signs of beetles are evident, thus preventingheavy infestation.
Q. When is the best time to spray?A. Early morning, after the dew is offthe plants and the flowers are open is the best time for spraying. Never sprayyour plants in the middle of a hot, sunny day. Be sure to water your plants aday or two before you spray them, since wilted plants are more likely to beinjured. If a plant is injured by spraying, its leaves will turn yellow andfall off (over a period of several days). Malathion and Lannate are both likelyto cause injury and should not be used on hibiscus.
Q. Some of my plants have yellow,rusty spots on their leaves.
A. This is Alternaria and it usually attacksplants that are deficient in fertiliser during periods of high humidity and wetweather. Fertilise the plants and spray with either Zineb or Benlate.
Q. The foliage of my plants has becomemalformed, stiff, twisted and deeply serrated and the flowers are like plasticor cardboard.A. This is phytotoxicity and it ismainly caused by hormone weedicides, usually 2‑4‑D or 2‑4‑5‑T.Care must be taken when using these toxic substances anywhere near hibiscus.Systemic insecticides used regularly or at stronger‑than‑recommendedrates can also cause problems with plants. The plants will eventually grow outof it. Hard pruning in spring usually helps. Cases of weedi‑ toxicityhave been recorded when neighbours have used these sprays and the slightestwind has carried the drift onto plants.
Q. Something is eating my plants!A. Before a cure can be found, thecause of the problem must be identified. Caterpillars and grubs leave small,round droppings where they have been feeding. Check for these and spray with Endo‑Carbaryl or Dipel. Snails and slugs usually leave their silver trails behind,and often congregate under branches close to ground level. They are alwaysactive on dewy mornings. Spray or bait with Mesurol (Methiocarb) orMetaldehyde.Grasshoppers also feed uponhibiscus look for large holes in leaves that have rough edges. Grasshoppers areusually easily visible and are best removed by hand as spraying is a littleineffective unless actual contact is made.There have also been casesof plants being eaten by some unknown marauder, and these have been traced torabbits, deer, possums and the odd kangaroo or wallaby has also been known totry hibiscus leaves.
Q. How do I get rid of ants?A. The answer to this is get rid ofthe reason why ants are on your plants and this is usually because they areattracted to the honeydew excreted by aphids. Endosulfan, Diazinon or Lebaycid may be used for this. Sometimes ants are attracted by the nectar that forms in the base of some flowers. A light application of Chlordane around the base of the main stem will deter them in this case.
Q. Can I use insecticide dusts on myplants?A. Yes, in fact many people believethe dusts have a better residual effect than liquid insecticides.
Q. My leaves are being eaten by acaterpillar, because I can see its droppings yet I cannot see any?A. Have a look in the soil just underthe plant and you will most probably find the culprit‑Army Worm. Theyfeed at night and during the day bury themselves in the soil. They are usuallysolitary and are best disposed of by hand once found; however, saturation ofthe soil with Endosulfan will control them.
Q. My plants develop black spots andmarkings on the leaves, particularly in cooler weather.
A. This is a fungus that attacks somevarieties of hibiscus more than others. Healthy plants resist infection betterthan unhealthy ones so fertilising helps, as does early applications of Benlateor Zineb.
Q. My leaves are curled and twistedand the flowers not as vibrant.A. Your plant appears to have developeda virus which may spread by the use of infected vegetative parts forpropagation and by insect vectors such as aphids and leaf hoppers. Severelyinfected or damaged plants should be destroyed and replaced with healthyplants, and sterilisation of grafting and pruning implements that have beenused on suspect plants is a commonsense practice.
Q. Every winter some of my plants dieback.
A. This is a fungus infection known asblack splash. The disease manifests itself by elongated, dark‑brown toblack areas on the stems or branches of hibiscus. These areas are usuallysunken, and as they grow they join and merge, eventually encircling the branch,causing it to die. Cut off and burn the affected portions. A spraying ofBenlate will often help in controlling black splash.
Q. My leaves are becoming crinkled.A. Always check on the undersides ofleaves for aphids. Often they have done considerable damage before they aredetected. Aphids usually are the cause of crinkled leaves. Use Endosulfan,Diazinon or Lebaycid for effective control.
Fertilising
Q. My buds are dropping off.A. There are several causes of buddrop and any one or a combination of several of them may cause the dropping ofbuds before they open. Many people are of the opinion that some insect snipsoff the buds as they appear to be cut cleanly at the break. This is not so.Hibiscus simply jettison buds when they are under stress, and they are putunder stress when they do not have enough water or food. Changes in weather andsevere infestation of Hibiscus Beetle may also cause bud‑drop. Ensurethat your hibiscus has regular watering and suitable fertilising. Excessiveamounts of nitrogen in some fertilisers have been known to trigger off buddrop. Overwatering can often leach some essential nutrients from the soil.Mulching helps conserve moisture and nutrients in the soil resulting in moreflowers. Hibiscus should never be allowed to dry out in the flowering season orbud drop will occur. Changeable weather during flowering time may also cause buddrop, particularly when there is a large difference between the minimum andmaximum temperatures. Heavy infestations of the Hibiscus Beetle will oftencause bud drop and regularly spraying is required to combat this pest.Sometimes certain varieties carry a bud dropping characteristic and whenhybridised with other varieties, the progeny may have this undesirable trait.The hybridiser should consider this factor when selecting parent plants. Somevarieties are notorious bud droppers, and full, heavy doubles are more likelyto drop buds than other types.
Q. My foliage is going brown aroundthe edges!A. Either too much fertiliser has been applied or else the plant was notwatered well before and after applying fertiliser. Regular watering will breakdown the fertiliser more rapidly, and any excess fertiliser still around theplant should be removed.
Q. How often should I fertilise?A. Hibiscus are gross feeders andrequire regular fertilising particularly during the flowering period. Nutrientsare leached from sandy soils much faster than heavier clayey soils, thereforesuch soils need fertiliser applied more often. In sandy soils a suitablefertiliser should be applied about every three weeks. In heavier soils everyfour to five weeks should be sufficient. At the end of the flowering season awell‑balanced fertiliser should be applied to carry the plants throughwinter. This same fertiliser should be applied after pruning. The regularapplications of recommended fertiliser should begin again in late spring as thefirst buds appear.
Q. What is the best fertiliser?A. Nitrophoska red, Aboska 27,Nitropep and Redchip are all brand names of suitable fertilisers for hibiscus.However, these are not available everywhere and therefore a fertiliser with anN.P.K. of around 13.13.21 or similar should be used. The high percentage ofpotash is necessary for continued production of blooms. Consult your localnurseryman to find a suitable fertiliser. Avoid foliage fertilisers with highnitrogen concentrations and slow‑release types.
Q. Do hibiscus like manure?A. Yes. Any kind of animal manure isbeneficial and provides the organic matter necessary to keep plants healthy.Hibiscus benefit from dressings of manure applied about every five to six weeksthroughout the flowering season.
Q. Will hibiscus tolerate lime?
A. Yes, although hibiscus prefer a pHof around 6.5 they do well in soils with pH readings from 5.5 to 7.8. When thepH level of the soil falls below 5.5 applications of lime are required to liftthese levels to a more suitable one for hibiscus. Regular dressings of manuremay also alter the pH levels of soil. In this case a light dusting of lime onceor twice a year is beneficial.
Q. Do hibiscus like foliagefertilisers?A. All fertilisers are manufactured tocertain requirements, and should be used according to your needs. Some foliagefertilisers are high in nitrogen and promote rapid growth in young seedlingsand cuttings; however they may cause bud drop on large flowering plants bycausing too much growth. Others aremore balanced and are ideal to use.Always read the label before applying, thus avoiding disappointment.
Q. Can I use poultry manure onhibiscus?A. Yes, particularly during theflowering period.
Q. Should I mulch my plants?
A. Yes, mulching is most beneficial inconserving both moisture and nutrients and helps in keeping weeds down.Mushroom compost is an ideal mulch; however there are many materials one canuse, and some of these are available more readily in some areas than others.
Q. My plants keep going to leaf.A. Your plants may not be gettingsufficient sunshine for the wood to harden into flowering wood, or else you areusing a fertiliser with too much nitrogen. There are a few varieties ofhibiscus that flower on older wood, and when these are pruned they tend toproduce a lot of foliage until such time as the wood throws out the short spursfrom which most flowers are produced on those varieties (e.g. 'Wilder's White'H. arnottianus).
Q. My leaves are turning yellow withgreen veinings.A. You have a deficiency problem. Mostprobably it is iron. Use chelated iron or GU 49 iron. Apply a completefertiliser and dressing of manure.
Q. What about compost‑can I useit on my hibiscus?A. Yes, a compost heap helps return tothe soil what the plants are taking out. Ensure that the compost is well brokendown before application or this process may take some of the available nitrogenfrom the soil. A good mulching several times a year is most beneficial.
Q. How do I apply potassium for betterblooms?A. The use of potassium nitrate toimprove the quality of hibiscus blooms is recommended during the floweringperiod. Use at the rate of V2 cup to 20 L water and apply one cup of thissolution to each mature plant. Potassium nitrate is also available in pelletedform and may be applied dry. Remember when applying either dry or in solutionform you run the risk of burning your plants unless you use very small amountsat any one time, and water well before and after application.
Planting
Q. Can I grow hibiscus in clayeysoils?
A. As long as good draining is provided, hibiscus will grow in heaviersoils. Where the subsoil is suspect it is a good idea notto dig into this for planting, but toraise the level of your garden bed sufficiently to allow for the drainage.Gypsum helps in breaking down these soils as does the addition of composts andmanures.
Q. My plants in the lawn don't do toomuch.A. If you are to grow hibiscus or anyother shrub for that matter in a lawn, then you must provide an adequate area freeof grass where the plant does not have to compete for food and water. Grasstends to take all the water and fertiliser away from plants and virtuallystarves them to death. The more one waters and fertilises the more the grassgrows. Provide an area about 750 mm (30 in) wide around your plants or betterstill make a good garden bed and grow your plants away from the grass.
Q. What depth of soil is necessary togrow hibiscus?A. That depends on the size ofhibiscus you want to grow! Most growers prefer to grow the smaller plantssimply because they can fit more varieties in. Naturally you cannot grow a 6 mhigh shrub in half a metre of soil. You can, however, grow very good hibiscusin only 300 mm (1 ft) of soil as long as they are the lowergrowing types. Insome areas where rocky outcrops restrict the depth of soil excellent specimensof hibiscus are to be seen. It's a little like growing plants in pots, as longas you keep the plants well watered and fertilised success is ensured. Wherethe depth of soil is limited care should be taken to never allow the plants todry out and lose condition.
Q. What is the best position forhibiscus?A. Full sun all day and protectionfrom cold winds in temperate areas. Partial shade and shelter from strong windsin tropical areas. In glasshouses or indoors in very cold areas.
Q. Will hibiscus do well in very sandysoil?A. Yes, in fact they prefer sandy soilas long as liberal amounts of good organic material capable of retainingmoisture and nutrients are added. Usually more fertiliser is requiredthroughout the season and mulching is necessary during summer, as is plenty ofwater.
Q. What is the best time for planting?A. Here again it depends on your area.It is not advisable to plant hibiscus during winter in temperate zones, andalthough they may be planted the rest of the year late spring and summer arebest. In tropical areas they may be planted all year around. Hibiscus syriacus and other cold‑tolerantspecies may be planted during winter when they are dormant.
Q. When can I transplant a hibiscus?
A. The best time for transplanting isjust after pruning in the spring. Plants that are cut back are much easier tohandle at this time. Generally hibiscus will transplant at any time other thanlate autumn or winter. Always treat plants with a little Hormone Formula 20after transplanting for best results.
Q. Will hibiscus grow under trees?A. They will, grow and survive undertrees but they will never flower or reach their potential unless planted in thefull sun. The trees would compete for food and moisture, resulting in stuntedplants. In tropical areas plants under trees are best if left in pots.
Q. Can I transplant a large hibiscus?A. Yes, but the question arises is itworth it? Large plants may require a lot of manpower to move them successfully,and take a long time to recover. This time could be better used by encouraginga new, healthier plant to vigorous growth to act as a replacement. Theimprovement in modern hybrids suggests that some older plants are best replacedwith better varieties.
Q. How close can I plant hibiscus?A. This depends entirely on whichvarieties you are planting. Some of the lowgrowing varieties can be planted asclose as 60 cm (2 ft) apart; medium growers about 1 to 1.3 m (3‑4 ft)apart and tall growers around 1.4 to 2 m (4‑6 ft) apart. Space must beallowed to fertilise and mulch, to keep the plants in tiptop shape.
Q. I have just taken out a large oldplant. Can I plant another in the same position?A. You can, provided that you replacethe old, burnt‑out soil with fresh, rich material. Plants take certaintrace elements from the soil, and when plants of the same species are plantedin the same spot they rarely do well unless the soil has been completelyreplaced or worked over thoroughly.
Pots
Q. How long can I keep a plant in apot?
A. This depends on the type of hibiscus and size of pot. Naturally a slow, lowgrowing variety will stay in a pot a lot longer than a more vigorous one.The rule is they can stay in a pot until such time as they begin to becomeunproductive and lose condition. Most plants will stay in a 45‑50 mm (18‑20in) pot for about five to six years.
Q. My plants in pots are not doing well.
A. This could be caused by a number of things ranging from bad drainage or position to incorrect potting mix. Checkthese things first, particularly ifyou have used general all‑purpose potting mix as this is sometimes notsuitable for hibiscus.
Q. What is the best size pot to use?A. A 45‑50 mm (18‑20 in)pot is ideal, however plants may be started in much smaller sizes and graduallyincreased until this size is reached.
Q. What is the best pot for hibiscus?A. This entirely depends on yourchoice of material. Hibiscus tend to do well in pots made from variousmaterials, however it is important to keep in mind that cement and terra‑cottacontainers dry out much faster than plastic ones, or ones made of wood.Hibiscus do prefer the normal basic pot shape, where the pot diameter is almostthe same as the pot height. They do not do as well in tall 'Ali Baba' typepots.
Q. Can I plant a small hibiscusdirectly into a large pot?A. Of course. It may even mature morerapidly than if kept in a smaller container, however a small plant in a largepot sometimes looks odd, and it is not encouraged for this reason only.Remember to fight the impulse to plant a few annuals or other plants to fill inwhile the hibiscus is growing. Too often these plants take over and smother thehibiscus.
Q. Do pots need raising off theground?
A. Pots raised off the ground dry out rapidly, particularly in windypositions and plants may lose condition. Pots with bottom drainage if left on asmooth surface can block up easily, therefore it is a good idea to raise thepot about 6 mm ( 1/4 in) to allow for better drainage without causing the plantto dry out excessively. A small section of flat fibro is ideal for this. Potswith side drainage do not need raising.
Q. How much drainage do I place in thebottom of a pot?
A. Good drainage is essential tomaintain plants in top condition. After a plant has been in a pot for severalyears the drainage holes tend to clog. For this reason plenty of drainage isrequired when planting hibiscus in pots. Roughly one‑quarter the heightof the pot should be used for drainage material. Old, broken tiles or pots,coarse clinker ash, and rough pebbles may all be used for drainage and coveredwith a layer of ashes or gravel which will act as a filter to prevent soilblocking the holes. Do not block off the drainage holes with material; they haveto be free to allow the passage of water.
Q. How often do I water and fertiliseplants in pots?A. A good watering every second dayshould be sufficient for most plants, depending on the weather. This regularwatering tends to leach out the essential nutrients more quickly than if theplants were in the ground. Therefore the fertiliser has to be applied to theplants more regularly than if the plants were in the ground. Fertilise aboutevery two to three weeks throughout the flowering period.
Q. When is the best time for pottingand repotting hibiscus?A. Any time except winter is all rightfor potting and repotting, although mid to late spring would be the ideal time.The plants have been pruned and are easier to handle then. Old, neglectedplants can be pruned heavily and root pruned and repotted into fresh soil inthe spring.
Q. What is the best soil for hibiscusplanted in pots?A. Every nursery will tell you thathibiscus will do well in the particular soil mix that they are selling, andsometimes this is true; however from past experience it is best to get soilfrom a specialist grower or mix your own. Hibiscus like a free‑draining,open mix with a good amount of humus. Two parts sandy loam, one part peat moss,one part cow manure or mushroom compost and one part coarse river sand makes anideal mix for plants in pots that are to be left outside all the time. If youare in a colder area it is better to use only one part sandy loam, particularlyif your pots are to be moved indoors during winter. It is best to avoid pre‑packedsoil mixes that are based on composted sawdust.
Q. What is the best position forhibiscus in pots?A. The more sun hibiscus are given thebetter, therefore they will do well in any position in the garden, be it asunny patio or deck, courtyard or wall, providing full sun is provided. One ofthe main advantages of hibiscus in pots is that you can make them mobile,following the sun around. This is very useful during winter when these plantslike that little extra warmth.
HybridisingQ. What is the best time to hybridise?A. Even before‑the blossomopens, the stigma pads are receptive to pollen, therefore early in the morningis the best time.
Q. How does one hybridise?A. Hybridisation is simply crossingtwo plants together to produce progeny that hopefully will have the desirabletraits of both parents. It involves dusting the male portions of flowers(pollen) onto the female part of the flower (stigma orpistil). In hibiscus this is easy asthe pollen sacs are a cluster of yellow anthers prominant on the staminalcolumn, and the stigma is recognised by the five stigma pads at the tip of thecolumn. Each of the five stigma pads must be dusted with pollen either with asoft brush or the bloom of the pollen parent may be picked and the pollenapplied directly.
Q. What time of year is best forhybridising?A. Some growers hybridise most of theyear around; however mid‑autumn to early spring is best. In coolerweather, the humid and foggy days are ideal. High temperatures dry out orinhibit the pollen so that it is not viable.
Q. How deep should I plant seed?A. Make a depression the size of afinger tip and 6 mm (%4 in) deep in the soil mix, then cover the seed with moremix.
Q. How long do the pods take to ripenafter hydridising?A. The pods may take anything fromforty to seventy days. They must be watched carefully as they begin to ripen,lest they burst and the seed is lost.
Q. What do I sow seed in?A. There are numerous seed mixes touse. Some growers have good results just using compressed fibre blocks. Amixture of sand and peat and ground‑up sphagnum is ideal. Vermiculite andpeat, perlite and peat, milled mixture of sphagnum and vermiculite or sterilesoil may be used as well. Sometimes it is a good idea to try several mixes outand use the one that gives the best results in your area.
Q. How long does it take seedlings tobloom?A. Most seedlings will bloom in 10 to14 months, provided that they are not cut back as this delays blooming. Plantsgrown in full sun will flower much quicker than those grown in shadedpositions.
PropagatingQ. When do I take cuttings?A. Hibiscus may be grown from threedifferent types of cuttings: tip cuttings which are taken in summer; firm woodcuttings which are taken in autumn; hardwood cuttings that are taken in latewinter or early spring.
Q. What do I put the cuttings in?A. Most cuttings do best if placed insmall individual pots. A mixture of sand and peat, perlite and peat or washedriver sand should be used.
Q. When can I graft?A. The best time for grafting isduring summer and autumn using the side graftmethod. Tip or cleft grafting isbetter when done in the spring.
Q. Can I graft several varieties onto one understock?A. You can, but unless you only havelimited space to grow just one plant it is not recommended. After a while onevariety will begin to dominate the others, reducing their vigour. Two varietieson the one understock is sometimes very interesting.
Q. What understock is best?A. This depends on your area. (Differentgrowers use different understocks in different areas. `Ruth Wilcox' (`AlboLacinatus') or `Wilders White' (H.arnottianus) are the best overall; `The President' and `Pride of Hankins'(`Landersii') are good for some areas.
Q. When do you cut the plastic tapesfrom your grafts?
A. Once you are sure you have a goodunion formed between your understock and scion, you should cut the tape toprevent constriction. It is best to do this eight to ten weeks after grafting.
Q. When is the best time to sow `SouthernBelle' seed?A. The best time is in early spring.`Southern Belle' will usually flower within a season in warm districts.
Q. When do you cut off the top part ofthe understock from a side graft?A. This varies, however the generalrule is when the leaves on the scion become mature enough to function properlyand support growth for that plant.
Q. How long do I leave cuttings beforethey take root?A. This again depends on the areawhere the cuttings are. Most cuttings should strike within eight to ten weeks.It is better to discard cuttings that take longer than, say, fourteen weeks tostrike as they generally don't produce strong plants.
Q. How long should cuttings be leftbefore they are potted?A. Once cuttings are rooted and theroot system is sufficiently strong the earlier the better. Cuttings progressmuch more rapidly once planted in good soil. Cuttings left in propagatingmaterials lose condition if left too long.
Q. Someone said to throw a plastic bagover my cuttings. Is this right?A. Cuttings strike better if kept in awarm, humid atmosphere, particularly tip and medium wood cuttings. Coveringthem with a plastic bag is an excellent way to provide this atmosphere. Theplastic may be removed regularly to prevent a buildup of fungus diseases whichalso proliferate under these conditions.
FlowersQ. My double flowering hibiscus hasturned single.A. Hibiscus blooms are governed by theweather conditions and produce their best blooms during summer and autumn.Flowers produced outside these times are sometimes out of season and we havedoubles reverting to singles and flowers getting smaller in size and deepeningin colour. The flowers will return to double as the new season approaches.
Q. My flowers only last a day thendrop off!A. The hibiscus flower only lasts aday, although many new hybrids have been bred which now last longer, even up tothree days. Do not think of this as a disadvantage; remember that many plantsbloom but once a year for only about two to three weeks and although their flowersmay last longer, they are often damaged by wind, rain and insects and one hasto wait another year for a repeat performance. With hibiscus a new flowerreplaces the old one the next day; a guarantee of fresh flowers all the timeover seven or more months a year,'
Q. My hibiscus was red with whitesplashes, now it is only red!A. Another case of flowers out ofseason. The white spots will reappear as the warm weather returns. Mosthibiscus with spots or splashes of different colours lose these in the off season.
Q. My blooms sometimes open withrolled edges!A. This is caused by the early morningsun hitting the flowers when they are covered with dew. It is often caused alsoby overhead watering during the heat of the day.
Q. My flowers sometimes miss a petal!A. The flowers don't actually miss apetal, they will still have five, but some varieties, particularly the semi‑doubleswith large exaggerated staminal columns, often produce these blooms. This iscalled crippling and it is just the variety that bunches the petals around thestaminal column causing the gap in the petals.
Q. How do I transport blooms withoutdamage!A. It is very hard to transport bloomsthat have already opened, therefore the trick is to pick them in the bud stageas they are about to open and place them in paper cones or drinking cups. Thebuds when removed from the cups will open spontaneously. Do not place them instyrofoam containers since petals will often stick to them and are torn onremoval. Buds may also be packed tightly in boxes, where again upon removalthey will open.
Q. Can I make my blooms last longer?
A. Hibiscus blooms will not last any longer whether they are left on the bush or picked, whether they are placed in water or not, and they do not usually last any longer when placed in a refrigerator. The refrigerator will however postpone the opening of buds for a day or so, but the flowers themselves will last no longer once they open. Select varieties that last longer for a start. Many new hybrids last considerably longer than older varieties.
WateringQ. How often should I water?A. A good watering twice a week in themiddle of the season is more beneficial than a light watering every day.Naturally plants may require more watering to keep their condition during a veryhot dry spell.
Q. When is the best time to water?A. Late afternoon or twilight is best.Avoid watering during the heat of the day.
Q. Is a sprinkler system good to usefor hibiscus?
A. Sprinkler systems are very good,however overhead watering may sometimes damage buds. Care must be taken toobserve the time of day they are to be used. Later afternoon is best.
Q. How much water should I give myplants?
A. Too much water causes as manyproblems as too little. Maintain a good moisture level in your soil without itremaining soggy. Too much water also leaches valuable nutrients from the soil.A good soaking equivalent to 25 mm (I in) of rain about twice a week would beideal.
Q. Is trickle feed irrigation anygood?A. Yes, a number of growers have hadexcellent results using this method of watering.
Q. When watering should I hose thewhole plant or just the soil?A. It is better to apply the water tothe soil most of the time, however a good hosing of the foliage every now andagain helps keep the plant clean. Dust and grime builds up on the leaves insome areas and regular hosing will remove this. Near the coast watering of thefoliage after a salt‑laden wind is recommended to reduce build up of salton the foliage.
PruningQ. When should I prune my hibiscus?A. The best time for pruning the rosa‑sinensistypes is spring; H. mutablis and syriacus varieties should be pruned in winter.
Q. How much do I cut from my plantswhen pruning?A. Most hibiscus relish being cut backabout one‑third all over. There are a few exceptions of course which dobetter when left unpruned. Plants that are very woody can be cut back half wayor more to induce new, healthy wood.
Q. My weeping hibiscus isn't weeping!
A. The weeping or waterfall hibiscus `Ruth Wilcox' (`Albo Lacinatus') is onehibiscus that does better when left unpruned. If it is pruned each year itproduces nice long, straight canes that give very few blooms, if left unprunedthese canes begin to weep and produce smaller laterals which become covered inflowers. A severe pruning every five to six years will maintain this variety ingood condition.
Q. My plants are very straggly!A. They require pruning to maintain anice rounded habit. Remove all lower, straggly branches, and trim the plantback one‑third in spring.
Q. Why do you have to prune?A. There are several reasons forpruning, the most important one being that pruning promotes strong healthygrowth which in turn produces the best flowers. It is also used to remove old,decayed and diseased wood, and to keep the plant in a desired shape.
GeneralIssuesQ. How long do hibiscus live?A. This depends a lot on its positionand care. Most plants begin to lose condition around twelve to fifteen years,however there are many specimens well over fifty years old around, particularlyof the early hybrids.
Q. My grafted hybrid hibiscus was a large yellow variety that was rather slow, now it is growing vigorously and producing small pink flowers.A. The understock has taken over.Hybrid hibiscus are grafted onto stronggrowing, hardy understocks, andsometimes if an eye has been left, this stock begins to grow and if not cut offearly it will completely dominate the grafted variety. Usually theseunderstocks have a different leaf which makes identification easier in the earlystages.
Q. My hibiscus don't begin to bloomuntil late in the season.A. They are probably not gettingenough sun. Check the sunlight situation first; if they are getting full sunthen more than likely something has happened to your growing tips‑possiblydamage by tip‑borer. If that's the case spray regularly during springwith Endosulfan.
Q. Why are Hawaiian hibiscus not ashardy as others?A. Hardiness depends entirely on thevariety. Most modern hybrids are loosely called Hawaiian hibiscus when many ofthem have been bred in
Q. My `Southern Belle' type ofhibiscus keeps breaking!A. These herbaceous hibiscus are veryprone to wind damage and must be planted in a sheltered position. They dobetter when four large stakes are driven into the ground about 45 cm (18 in)apart around the base of the plant and then strong wire netting wrapped aroundthe four stakes holding the canes in an upright position. It is important to dothis just as the shoots begin appearing in the spring, otherwise damage will bedone to the plant.
Q. Are there any Australian nativehibiscus?A. Yes, there are over thirty‑fivedifferent species of hibiscus indigenous to
