Garden Talk

with Rebecca Jordi


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Q: The buds of my hibiscus are turning yellow and dropping off. What is wrong?

Hibiscus bud midge maggot

Hibiscus bud midge maggot

A:  After opening one of the yellowing buds we discovered the hibiscus bud midge maggot, Contarinia maculipennis.  The female midge deposits eggs on the tips of the newly forming buds and within 24 hours the maggot develops and starts to feed on the bud.  It takes about one week for the insect to mature to the next stage; then they drop to the ground to pupate. The soil must be moist, which is generally not a problem in our landscapes.  It will take about 2 -3 weeks to mature into an adult. The adult midge is very small – similar to a mosquito. Although hibiscus is the favorite, the bud midge has been known to also infest tomatoes, jasmine, plumeria, other vegetables and ornamentals. There are other reasons for flower buds to turn yellow and drop off such as over watering, too much nitrogen, thrips or aphids, and very hot, dry weather.  However, since I found the maggot, I am going to blame it on the bud midge.  The best thing for homeowners to do is to be sure to clean up any buds and leaf litter which have dropped to the ground.  If the hibiscus plants are in the ground they may not need supplemental watering aside from what we get with rain.  Remember, the midge requires moist soil to pupate.  Contact chemical sprays don’t work well since they cannot penetrate the bud.

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Q: Please tell me the proper times to water and how much to water. Are we really supposed to water shrubs differently than grass? I am so frustrated at all the different pieces of information, I just want someone to make it simple for me.

Sprinklers

Sprinklers

A:  Thank you so much for your timely question.  We will start with the law from the St. Johns River Water Management if we do NOT receive sufficient rain:

  • Daylight saving time (DST): Second Sunday in March until the first Sunday in November (summer)
  • Eastern Standard Time (EST): First Sunday in November until the second Sunday in March (winter)
  • An odd numbered addresses end in 1, 3, 5, 7 or 9. DST – Wednesday/Saturdays; EST Saturdays
  • An even numbered addresses end in 0, 2, 4, 6 or 8. DST – Thursday/Sundays; EST Sundays
  • Water only when needed and not between 10 a.m. and 4 p.m. *We recommend watering from 4am – 10am so any extra water has time to dry off the blades to reduce disease.  We do not suggest watering in the evenings.
  • Water for no more than one hour per zone. *We recommend you measure your output with the ideal amount at each watering measuring between ½ inch and ¾ inch.  Our grasses grow very well in sandy, well-drained soil and like to be watered deeply but less often to produce strong root structures.
  • Restrictions apply to private wells and pumps, ground or surface water and water from public and private utilities. People often believe since they have their own well that is doesn’t matter how much they use but the same restrictions apply to private wells.  *We recommend allowing the grass to tell you when to water.  Once the blade begins to slightly fold, or has a blue-green color then water the grass.
  • *We recommend separating the irrigation zones so the flower beds and hedges are watered differently.  Most mature hedges and woody ornamentals do not require irrigation once established and watering twice a week would be excessive and unnecessary. In addition, so many disease issues for lawn grasses and shrubs are caused by over watering.
  • *University of Florida/Institute of Food and Agricultural Sciences (UF/IFAS) recommendations.


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Q: What is the name of the insect and what does it do? It looks like it has a long stinger at the end of the abdomen.

Broadnecked Root Borer

Broadnecked Root Borer

A: I believe the insect you brought in to the office is a Broad-neck root borer, possibly Prionus laticollis.  The female is much larger than the male, growing to two inches or more. The structure you see at the end of the abdomen is actually called an ovipositor, not a stinger. Ovipositors are structures on female insects in which they deposit eggs. This particular insect deposits eggs into the ground around trees and shrubs. The yellow eggs are about 1/8 inch long developing into larvae which then feed on the living roots of trees and shrubs. One female may lay as many as 100 eggs in clusters. The larvae may be as long as 3 ½ inches with black mandibles (very scary).  Broad-neck root borers prefer deciduous trees of the forest but have been known to feed on fruit trees and shrubs such as peach, pear, apple, blueberries and even grapes. The complete life cycle takes about three years. Adults emerge from the ground between June and August eating the foliage of trees and, on some occasions, even damaging the fruit.  Generally, the adults feed at night but stay hidden during the day. The smaller males are seen more often as they are attracted to light. Broad-necked root borer’s range is from Quebec and Ontario to Minnesota and as far south as Florida.  Because the larva of this insect feeds exclusively on the roots of trees, the only visible symptoms are limb die-back and the yellowing and/or thinning of foliage. Borers can completely destroy young trees and make older trees more susceptible to being blown over.  Prevention is the best way to deal with a borer. Keep grass, leaves, mulch, bark and other litter cleared away from the bases of trees. This prevents the borer from having a place to hide and makes it more visible to predatory birds. In addition, avoid over pruning, over fertilizing and over watering trees – all of these can cause additional stresses. 


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Q: Are there any heirloom hot peppers?

Chocolate Habanero

Chocolate Habanero

A:   Yes, we have many heirloom hot peppers which can be grown in several parts of Florida. Remember, the term “heirloom” vegetables means you can use the seeds from the fruit and produce future plants year after year. Hot peppers are native to Central and South America where they have been part of the human diet for thousands of years. Hot peppers were named by Christopher Columbus who mistakenly thought they were related to Piper nigrum or black pepper because they had a similar pungency. Columbus returned to Spain with some of the peppers, and its popularity rapidly spread throughout Europe, India, China, Korea, Thailand and Japan. Hot peppers are known for their pungent flavor. The pungency is caused by the compound capsaicin, which is measured in Scoville heat units. A pepper with more capsaicin will have a higher Scoville heat unit. Bell peppers have a Scoville unit of zero, while the hottest peppers have a Scoville unit greater than 1,000,000. The pungency level is genetic, but it can be influenced by environmental stress. A hot pepper from the same variety grown in hot, dry conditions would have higher capsaicin and a more pungent flavor than a hot pepper grown in cooler, humid conditions. Heirloom hot peppers are closely related to other vegetables in the family Solanacea, such as potatoes, tomatoes, tobacco, and eggplants. This means the same diseases commonly found on Solanacea plants will attack peppers. A few of those diseases are bacterial leaf spot which shows up as small, water-soaked or greasy spots on leaves. These spots are often accompanied by small, light green, raised spots on fruit which ultimately become enlarged and turn scabby. Viruses can also be found on peppers such as pepper mottle, potato virus Y, tobacco etch, and tobacco mosaic virus. These diseases create stunted plants, fruit and leaf malformation, mottling, and leaf mosaics, but it is really tough to identify these viruses in the field.  Most often, specimens need to be sent to the University of Florida pathology lab for absolute identification.  Controlling weeds and insects is a critical strategy for managing the spread of the diseases.  Remember to avoid overhead irrigation, and reduce handling, harvesting or pruning plants while the plants are wet. The attached publication from the University of Florida provides a long list of heirloom peppers to try.  Plant peppers in full sun and only in the warm months of the year.  http://edis.ifas.ufl.edu/hs1244


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Q: I am growing several types of peppers but my Ghost peppers are not producing well. What could be the problem?

Ghost Pepper

Ghost Pepper

A:  The Ghost pepper, Bhut jolokia, requires temperatures above 70º degrees F to produce fruit or peppers. We are just now reaching those temperatures on a regular basis. We may not be hot enough for a long enough period of time to produce this hot pepper but be patient and give it some more time and you may see better results. If you are not successful, do not be too hard on yourself, this pepper is typically grown in a much hotter climate than Northeast Florida.  The Ghost pepper is also known as naga jolokia, bih jolokia, ghost chili pepper, red naga chili, and ghost chili, is an interspecific hybrid cultivated in the Indian state of Assam. The name “bhut jolokia” comes from the Bhutia tribe who used to bring it to the valley of Assam for trade. DNA tests showed it is an interspecies hybrid, mostly C. chinense with C. frutescens. In 2007 Guinness World Records certified the ghost pepper as the world hottest pepper, with 1,041,427 Scoville units, 401.5 times hotter than Tabasco sauce (2,500 to 5,000 Scoville units). It currently is ranked in third place following ‘Carolina Reaper’ (Guinness World Records 2013) and ‘Trinidad Moruga scorpion’ (Bryan 2012), which are 2,009,000 and 2,200,000 Scoville units, respectively, but these peppers are rarely grown in the Miami-Dade County region. Ripe bhut jolokia peppers are approximately 2.4 to 3.3 inches long and 1.0 to 1.2 inches wide, with a red, yellow, orange, or chocolate color and very thin skin. The fruit can be rough, wrinkled, dented, or smooth. Bhut jolokia is widely used as an ingredient in spicy food and as a remedy for summer heat in some countries. It is used in both fresh and dried forms and has a unique flavor. In addition, the dried powder of such hot peppers can be developed into pepper spray as a self-defense product. This information comes from the University of Florida publication titled: Pepper Production in Miami-Dade County, Florida.  http://edis.ifas.ufl.edu/tr010


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Q: What it the name of the plant I see along the roadsides with round, white flowers?

Buttonbush

Buttonbush

A:  This is a repeat question which I have answered in the past but since the plant is showing the beautiful, round, white flowers now I am sure to get this question again. “I suspect you are referring to the Buttonbush, Cephalanthus occidentalis.  Buttonbush grows as a shrub or small tree – typically growing 10 or 20 feet tall. This plant is deciduous, losing its leaves for 1 or 2 months in winter. Buttonbush is a native plant which occurs in swamps, ponds, and stream banks throughout Florida. Keep that in mind if you are thinking about adding it to your landscape, it is not a true drought tolerant plant. However, it might make an excellent choice for areas around retention ponds. It flowers from early spring to late summer and provides nectar for many important native pollinators. Waterfowl and shorebirds consume the seeds of common buttonbush. White-tailed deer browse foliage in the northeastern United States. Wood ducks use the plant’s structure for protection of brooding nests. Butterflies, bees, and hummingbirds are attracted to common buttonbush for its nectar and bees use it to produce honey.  Buttonbush is named for its ball-like clusters of small white flowers around fruits. Flower balls can be an inch or more across which dangle from long stalks. Buttonbush leaves are about six inches long, elliptic, and tapering to pointed tips. As buttonbush becomes older, its bark becomes rough and bumpy. According to the USDA Common buttonbush contains the poison Cephalathin which can induce vomiting, paralysis, and convulsions if ingested. Therefore, do not use this as a stick for roasting marshmallows.  http://edis.ifas.ufl.edu/pdffiles/FP/FP11700.pdf