In the last few weeks, more garden pests have arrived! It is a fact of life in northwest Florida that we will have a few things in our garden including heat, moisture (humidity and rainfall), and BUGS! With a cooler spring the arrival of some of the troublesome pests in the garden seemed to be delayed a few weeks. It was nice while it lasted but the insect pests are here to stay until frost in the fall or winter (at least we hope for a frost this year).
There are thousands of insects that you can see in your garden. It’s wise to identify them before making a decision to spray an insecticide or remove them by another method. Insect samples can be taken to your local county extension office for identification.
In this article we will just discuss one of the top insect pests in the vegetable garden, caterpillars, and what you can do about them.
Mature larva of the cabbage looper. Photograph by John L. Capinera, University of Florida.
Beet armyworms, fall armyworms, hornworms, cabbage loopers, southern armyworms, tomato fruitworms, and other caterpillars love to feed on tomato foliage and fruit. They will show up eventually on tomato plants in the garden, if not this year then in the future. These larvae are immature moths and cause a lot of damage if left unchecked. The homeowner can control them effectively with Organic Materials Review Institute (OMRI) approved pesticides. A bacterial biological insecticide called Bacillusthuringiensis, also referred to as B.t., can be very effective in controlling these caterpillar pests. B.t. is a stomach toxin to these pests and will cause them to quit eating and starve to death. The key to using B.t. effectively is to routinely apply it before the caterpillars hatch from their eggs as the smaller caterpillars are easiest to control. Larger caterpillars are more difficult to control.
For more information related to using OMRI pesticides:
Coral ardisia is also known as coral berry, spice berry, and scratchthroat. It was introduced into Florida in the early 1900’s for ornamental purposes.
Coral ardisia. Photo credit: Les Harrison.
In the ensuing years it has since escaped cultivation and become established in hardwood hammocks and other moist woods of natural areas and grazing lands. Specimens have been collected from 19 western and south-central Florida counties as of 2004.
This evergreen sub-shrub reaches a height of 1.5 to six feet and tends to grow in multi-stemmed clumps. Leaves are alternate, 8 inches long, dark green above, waxy, without hairs, and have scalloped margins and calluses in the margin notches.
Flowers are typically pink to white in stalked axillary clusters, usually drooping below the foliage. The fruit is a bright red, globose, single-seeded berry, measuring approximately 0.25 inches in diameter. White-berried populations are also known to exist.
Coral ardisia is considered invasive. Control of coral ardisia may be accomplished by two methods. A low-volume foliar application of Garlon 4 or Remedy provides suppression of this plant. Complete foliar coverage is essential to success and retreatment will be necessary for complete control.
Basal bark applications with Garlon 4 or Remedy in an oil carrier can also be utilized for suppressing this invasive weed. Do not apply more than 8 quarts of Remedy or Garlon 4 per acre and treat no more than ten percent of the total grazed area if applying greater than two quarts per acre.
Do you have azaleas or camellias with leaves that are thickened, curled and waxy in appearance? This is fairly common this year and is caused by a fungus.
Camellia leaf gall on Sasanqua Camellia. Note swollen, malformed leaves. Photo credit: Larry Williams
Exobasidium vaccinii is a fungus that causes leaves, and in some cases flower petals, to enlarge abnormally and is commonly referred to as azalea leaf and flower gall.
Infected azalea and camellia leaves become large and distorted. Eventually a white powder covers the galls. The white growth consists of spores, which is how the fungus reproduces. Galls ultimately turn brown and harden. Not every leaf will be infected.
The disease relies on airborne spores produced in the whitish mold on the surface of galls in late spring to early summer to reproduce. Some plant pathologists believe that once the spores are released, they are blown and washed to leaf and flower buds where they cause new infections. Galls then form the following spring. Other plant pathologists think that the spores are produced the following year from the old dried, brown galls that fell to the ground around infected plants the previous year. In spring, the spores blow and splash onto new leaves and petals as they emerge causing infection. One or both lines of thought may be true. But in either case, it’s important to remove and dispose of infected leaves before they turn white with spores.
Once you see evidence of infected leaves, it’s too late for chemical control. Besides, there currently is no effective or practical fungicide to control this disease in home landscapes. But you can reduce the amount of infection the following year by pruning infected leaves and throwing them away before spores develop. After removing infected leaves with galls, never leave them on the ground around the plants.
It’s best to bury, burn or place infected leaves in a plastic bag and throw them away. This disease is more severe during a cool, wet spring, which we experienced this year. It’s advisable to not add to the problem by artificially providing the “wet weather” the spores need by frequently using an overhead sprinkler and keeping the foliage wet in the spring during disease development. This is exactly what this and many other plant diseases need – wet conditions. It’s best to water established landscape plants on an as needed basis.
In the home landscape, the fungus does not cause any long-term problems for the plant. It just makes the plant’s leaves look ugly. Infected leaves will usually fall prematurely.
Aphids (Macrosiphum gaurae) feeding on gaura. Photo: Julie McConnell, UF/IFAS
Every day, if I get home before the sun goes down, I like to walk around my garden and see how things are growing. At this time of year there are always new surprises in the garden – plants leafing out after a winter break, new flower buds and blooms, and of course sometimes garden pests.
My daughter and I collected some flowers last weekend and after they sat on the table for a few minutes I noticed pink bugs crawling around on the gaura stems. On further inspection I realized the stem was covered in aphids which made me go out to look at the entire plant. I found a prolific population
of aphids on the gaura and also lady beetle larvae hunting and eating the aphids! Instead of mixing up a bottle of insecticidal soap I decided to let the lady beetles do their job and just monitor the situation.
Multicolored Asian Lady Beetle Larvae feeding on aphids. Photo: Julie McConnell, UF/IFAS
Five days later I went to show my example of natural biological control to a visiting friend and we could not find a single aphid on my plant. This may not be the typical response, usually I see some level of both predator and prey but in this instance the lady beetle did a fantastic job of controlling the aphids.
So, did they eat every last one? Probably not, they likely ate many of them and the others left the plant because the predator pressure was too great. However, either scenario saved my plant from severe damage which was the overall goal.
The panhandle of Florida is a great place to grow citrus with our plentiful sunshine and sandy soil. But some varieties do better than others. Here are some that thrive in the more northerly climes of Florida:
Nagami kumquat. Photo credit: UF/IFAS.
Satsuma mandarin is cold hardy to 15°F once established. There are a few different available cultivars with fruit ripening October through December. Fruit needs to be picked promptly when ripe.
Kumquat is cold hardy to 10°F once established. ‘Nagami’ and ‘Meiwa’ are the two common cultivars of the small tart fruits. Fruit matures in fall and winter and holds fairly well on the trees.
Calamondin is a lesser known variety that bears small fruit that resemble tangerines. The tart fruit is great for jams and chutneys. Fruit is borne all year.
Some of the sweet oranges that do well in the panhandle are Navel, Hamlin and Parson Brown. They are cold hardy to 14°F once established and are harvested November through January.
Minneola or Honeybell tangelo is also hardy to 14°F and harvested in January. This is a cross between a Duncan grapefruit and a Darcy tangerine. This bell-shaped fruit is very juicy and sweet. Unlike the other citrus varieties, it needs another citrus nearby for cross-pollination in order to produce an abundant crop.
Meyer Lemon is the choice to make if you would like to grow lemons in the panhandle. Other lemons may be damaged by our occasional freezes.
Grapefruit and lime can be grown – although unreliably – on the coast with protection from northwestern winter winds. They are much more susceptible to freezes in more northerly panhandle locations.
Citrus canker symptoms on leaves, fruit and stem. Photo by Timothy Schubert, FDACS
There are threats to our dooryard and commercial citrus from pests and disease. Only vigilance will help to combat the challenges so that we may continue to grow and enjoy our citrus. What can we do to protect our citrus?
Report any serious diseases like suspected citrus canker or citrus greening to the Division of Plant Industry by calling toll-free 1-888-397-1517. Inspections and diagnosis are free. Citrus canker has been confirmed in south Santa Rosa County in the past 3 years.
Purchase citrus trees only from registered nurseries – they may cost a little more but they have gone through an extensive process to remain disease and pest free. That will save you $$ in the long run!
Don’t bring plants or fruit back into Florida – they may be harboring a pest!
Citrus trees or fruit cannot move in or out of the State of Florida without a permit. This applies to homeowners as well as to the industry. This rule protects our vital dooryard trees and citrus industry.
People are, by nature, skeptical. Humans are and have always been questioners of the world around them and that’s a good thing! For instance, when one reads a sensational article on Facebook or watches an infomercial selling a too-good-to-be-true product he/she is immediately dubious of the veracity of the claim. Given this innate sense, why do consumers take plant tags displayed on retail plants and the information listed there as infallible fact when in reality they are often full of hyperbole and misleading?
I do not mean to insinuate that nurseries and landscape professionals are intentionally leading consumers astray. They are not. However, there is much incorrect information disseminated to consumers by the green industry on plant fact sheets. Take my titular example, ‘Little Gem’ magnolia is widely advertised and sold as a “dwarf” magnolia, only growing 15’-25’ tall. If given proper care, it will grow to that height…in seven to ten years. Given enough time, ‘Little Gem’ has will grow in excess of forty feet. People plant this cultivar under the eaves of single story houses on a regular basis! I promise that cute little magnolia you were told would grow 15’ tall will look rather silly when it is four times the height of your house. Take another example, how many times have you seen or heard of ‘Acoma’ crapemyrtle being sold as a “semi-dwarf” cultivar that grows to 10’ in height for use in a tight spot of the landscape in lieu of the much larger ‘Natchez’? It will fill that tight spot and fill it rather quickly. ‘Acoma’ can easily reach 20’ in height and width at maturity, engulfing its intended area.
Typical plant tag. Notice the “Average Size” section. This is where consumers should use discretion.
So why does this happen? Why are plant tags so often mistaken? There are two primary reasons that correct mature sizes are not given. First, in the competitive world of plant breeding and introduction where there can be hundreds or thousands of cultivars of a single species, it is of utmost importance to introduce plants as quickly. Quick introduction is necessary because others are probably working to find similar traits; therefore, if one notices that a plant possesses a drastically different flower, flowering pattern, leaf shape, leaf size, or growth habit, the plant is often rushed to market. This leaves little time for complete trials of the plant to see what it would look like at maturity.
Secondly, most well-adapted or native trees/shrubs have relatively long life spans. A crapemyrtle or magnolia can easily grow and thrive in a landscape for thirty years or more before reaching maximum size. Nurseries simply do not have time to evaluate plants that long. Many nurseries, due to vagaries of economic cycles and length of career spans, don’t even exist for thirty years much less trial a single plant for that length of time!
In conclusion, nurseries are not likely to change their plant tag practices, but there are a couple of checks consumers can use to make sure they buy an appropriate plant for the scale of their site. First, it is a good rule of thumb to double the advertised plant height to arrive at a better idea of the plant’s mature size. Second, drive through established neighborhoods and observe what certain plants look like in a mature landscape. This will give one an idea of what the plant is capable of. The third and best option is to consult your local County Extension Office. They will be able to offer research-based information to help you make the right decision in your plant choices. Keep this in mind the next time you are thinking of buying the latest, greatest plant at your local nursery!
