Surefire Shrubs for Containers

Growing in containers can be one of the most versatile ways to add color, texture and mobility to the landscape.  However, gardeners generally reach for finicky annuals to fill their pots with pizzazz.  The problem with this strategy is that most annuals and perennials need to be watered constantly, fertilized regularly, and changed out with the seasons.  That sounds like a little bang for a whole lot of buck!  I and most of the real plant people I know fall squarely in the school of lazy gardening and believe there is an easier, less intensive, and ultimately less expensive way to get the same result.  This can be accomplished by thinking outside the box and using an alternative class of plants that can fit the same bill of providing color and texture in pots without the headaches and have been sitting on the shelves right in front of us the whole time, the shrubs.

It is beyond me why shrubs aren’t used as container plants more often.  Maybe the reason for the lack of use is pure perception; after all, no one with any sense would plant a giant, coarse green meatball or an enormous antebellum azalea in a decorative pot on their front walk.  Recent innovations by plant breeders have left this argument moot though as new introductions of old species have revived interest in the entire group.  Many of the best of these new cultivars sport traits perfect for container culture (dwarf growth habit, increased flowering, and interesting texture and form) while preserving the ironclad, undemanding nature of their parent plants.  The following are a few of my favorite new shrub introductions for container growing!

  • ‘Purple Pixie’ Loropetalum

    Purple Pixie loropetalum is a low-growing shrub that can spill beautifully out of a container. (Photo by MSU Extension Service/Gary Bachman)

If interesting architecture is what you require in a plant, ‘Purple Pixie’ must be on display in your yard.  This dwarf cultivar of the wildly overused purple shrub Loropetalum chinense has taken the horticultural world by storm.  The unique combination of true purplish foliage that only greens slightly in the hottest summer sun, ribbon-like pink spring flowers, and a graceful weeping habit make ‘Purple Pixie’ a winner.  Give this plant a medium sized container (at least 12” in diameter), water when the soil begins to dry, fertilize infrequently with a slow-release formulation, site in full sun to partial shade, and enjoy for many seasons to come.

  • ‘Sunshine’ Ligustrum

This is definitely not your granddaddy’s Ligustrum.  Gone are the rampant growth, sickly sweet smelling flowers, and the aggressive nature of ‘Sunshine’s’ parent Chinese Privet (Ligustrum sinense).  ‘Sunshine’ is a sterile cultivar with dwarf characteristics (growing 4-5’ with infrequent light pruning), vivid yellow-chartreuse foliage, and most importantly, no flowers.  All ‘Sunshine’ asks of us is plenty of sun, occasional fertilizer and a light haircut once or twice a season!  Use this plant to frame a dark flowerbed or in a container as a companion to the previous plant, ‘Purple Pixie’ Loropetalum for an extremely striking combination!

‘Sunshine’ Ligustrum. Photo courtesy of JC Raulston Arboretum.

  • ‘Baby Gem’ Boxwood

A new take on a landscape standard, ‘Baby Gem’ is an exceptionally compact and slow growing cultivar of Buxus microphylla var japonica.  All the same features gardeners love about traditional “full-size” boxwoods remains (tight, formal growth habit, ability to prune into many different shapes and ironclad constitution) but with ‘Baby Gem’ are delivered in a perfect package for a pot.  This little “gem” of a plant is perfect for use in a smallish container to frame a formal landscape or to give a sense of order to an informal container garden or border!

So if you’re ready to stop replacing all of your potted plants each and every season, reach for one of these shrubs the next time you are at a garden center.  You’ll likely be rewarded with compliments on your creativity, four season interest from the plants themselves, and more time to enjoy being in your garden instead of laboring in it!  As always, if you have any questions about this or any other horticultural topics please contact your local UF/IFAS Extension office!  Happy Gardening!

Safety and Best Management Practices Essential for Pesticide Use

Many folks may not realize it at first, but everyone is using pesticides. Have you recently used a mold or mildew removal cleaner in your bathroom? Do you apply flea & tick powder to your pet? It is a misconception that only farmers, ranchers and lawn and garden enthusiasts are pesticide users. So, let’s all keep safety in mind, as any of these household and outdoor chemicals can be dangerous.

Example of Precautionary Statement and Personal Protective Equipment Instruction. Credit: UF/IFAS Extension

Pesticides include a wide range of products that either kill or repel pests. These pests can be insects, nuisance animals, weeds, plant pathogens, molds and other undesirables. Are pesticides necessary? Maybe not. Pesticides should be considered as a last resort. Using an integrated pest management (IPM) approach is an environmentally safe, and often, economical way to reduce pests. Usually, there are four steps involved in IPM, starting with the practice with the least environmental impact, until a solution to the pest problem has been found. For example, say that you are having issues with aphids in your garden. The IPM approach may begin with cultural measures (ex. avoiding high nitrogen fertilizer as it promotes lush growth that creates a favorable environment for aphids). This may be followed by mechanical measures (ex. use of insect netting) and if problem still exists, biological measures (ex. release of parasitic wasps). As stated earlier, the last resort would be chemical measures (ex. applying pesticide). There are varying IPM strategies for different pests. Please visit the UF/IFAS IPM website for more information: http://ipm.ifas.ufl.edu/

When pesticide usage is necessary, it’s important to select the right chemical(s). Once the pest has been identified, check pesticide labels under the section “pests controlled”. Never assume a pesticide will control a pest not listed under this section. Often, there are numerous products that list a common pest. Always consider five factors when determining the right pesticide: environmental friendliness, effects on beneficial organisms, ease of use, available application equipment and cost.

Once a pesticide has been chosen, be sure to follow the directions. It is critical to mix a concentrated pesticide accurately, therefore follow the product label. Diluting concentrated pesticides by mixing with water is necessary to achieve the correct concentration. Increasing the concentration is dangerous and will have a negative response. The response can be environmental harm, damage to desirable plants and beneficial organisms and above all, it’s illegal to apply rates greater than the specified label.

Remember, pesticide exposure can be life threating under certain circumstances. Pesticides can enter the body in several ways. The most common entries are mouth, inhalation, eyes or skin. Always wear personal protective equipment (PPE) when mixing and applying pesticides. Precautionary statements for humans and domesticated animals will be supplied on the product label. Examples of safety information are: causes eye irritation, harmful if swallowed or avoid contact with eyes or clothing. Dress accordingly based on the safety information supplied by the product label. Some types of PPE are long rubber gloves, goggles, respirators, waterproof apparel and rubber boots.

All pesticides should be stored out of the reach of children. Pesticides stored in any container not deemed pesticide compatible (ex. canning jars and food or soft drink containers) is illegal. For more information on pesticide safety and best management practices, contact your local county extension office.

Supporting information for this article can be found in the UF/IFAS EDIS publication: “Homeowner’s Guide to Pesticide Safety” by Frederick M. Fishel: http://edis.ifas.ufl.edu/pdffiles/PI/PI05100.pdf

UF/IFAS Extension is an Equal Opportunity Institution.

Gardening in Containers Workshop – August 19

The Jackson County Master Gardeners will host a “Gardening in Containers” Workshop on Saturday, August 19 from 9 AM to 2 PM at the Jackson County Extension Office, 2741 Penn Ave., Marianna, FL.  The workshop will give you simple tips on growing vegetables, herbs, and flowers in containers.  Bring your own unique container.  Plant material and soil will be provided.  The workshop is $25 and includes a home cooked lunch.  Please see the flyer below for more details and call 850-482-9620 to pre-register.

Recent Weather Fueling Fungi

Florida’s panhandle has received quite a bit of rain this summer. In the last three months, depending on the location, approximately 15 to 35 inches of rain have come down, with the western panhandle on the higher end of that range. In addition to the rain, we all know how hot it has been with heat index values in the triple digits. And who can forget the humidity?! Well, these weather conditions are just the right environmental factors for many types of fungi, some harmful to landscape plants, most not.

In the classification of living things, fungi are divided into their own Kingdom, separate from plants, animals, and bacteria. They are actually more closely related to animals than plants. They play an important role on the Earth by recycling nutrients through the breakdown of dead or dying organisms. Many are consumed as food by humans, others provide medicines, such as penicillin, while some (yeasts) provide what’s needed for bread and beer. However, there are fungi that also give gardeners and homeowners headaches. Plant diseases caused by various fungi go by the names rusts, smuts, or a variety of leaf, root, and stem rots. Fungal pathogens gardeners may be experiencing during this weather include:

  • Gray leaf spot – This fungus can often show up in St. Augustine grass lawns. Signs of this fungus include gray spots on the leaf (very descriptive name!). This disease can cause thin areas of lawn and slow growth of the grass.

Gray leaf spot on St. Augustine grass. Credit: Phil Harmon/UF/IFAS.

 

  • Take-all root rot – This fungus can attack all our warm-season turfgrasses, and may start as yellow leaf blades and develop into small to large areas of thin grass or bare patches. The roots and stolons of affected grasses will be short and black.

 

Signs of take all root rot. Credit: UF/IFAS.

Powdery mildew – This fungus can be found on many plants, from roses to cucumbers. It looks like white powder on the leaves and can lead to plant decline.

  • Armillaria root rot – This fungus can infect a variety of landscape plants, including oaks, hickories, viburnums, and azaleas. Symptoms can include yellowing of leaves and branch dieback, usually in adjacent plants. Old hardwood stumps can harbor this fungus and lead to the infection of nearby ornamentals.

Because fungi are naturally abundant in the environment, the use of fungicides can temporarily suppress, but not eliminate, most fungal diseases. Therefore, fungicides are best used during favorable conditions for the particular pathogen, as a preventative tool.

Proper management practices – mowing height, fertilization, irrigation, etc. – that reduce plant stress go a long way in preventing fungal diseases. Remember that even the use of broadleaf specific herbicides can stress a lawn and exacerbate disease problems if done incorrectly. Since rain has been abundant, irrigation schedules should be adjusted to reduce leaf and soil moisture. Minimizing injury to the leaves, stems, and roots prevents stress and potential entry points for fungi on the move.

If you think your landscape plants are suffering from a fungal disease, contact your local Extension Office and/or visit the University of Florida’s EDIS website at http://edis.ifas.ufl.edu for more information.

Not all Palm Fertilizers are the Same

It is common in Northwest Florida for palms to show signs of nutrient deficiencies. In general our sandy soil is often nutrient poor and available nutrients can easily move out of soils with frequent rainfall.  In landscapes where fertilization is occurring, often the wrong types of fertilizer are applied.   Fertilizer miss-application actually increases nutrient problems for the palm.

Palms can be deficient in many nutrients but the most common deficiencies we see in landscapes are from inadequate amounts potassium and magnesium. The simple solution would be to purchase a fertilizer labeled for palms to correct the problem.  The difficulty is that most easily available fertilizers for palms do not have the correct form of nutrients that are required for the problems.  With the exception of nitrogen, all other nutrients are in a quick release form so while the slow release nitrogen lasts for 2-3 months, all other nutrients have been used up.  In response, the palm is encouraged to grow by the nitrogen but does not have enough of the other critical nutrients to carry out vital plant functions.  What we see is often older leaves that are yellowing, browning, and die off before they should because the plant is pulling any available potassium and magnesium from old fronds to support new growth.  Without the application of proper nutrients to the soil, the deficiency can continue until even new fronds are affected or the palm dies.

The fertilizer used for lawns does not have all the slow release and correct forms of nutrients for the palms. Older leaves turn yellow and brown indicating potassium deficiency. Photo by Beth Bolles, UF IFAS Extension Escambia County.

There is a solution that will help keep your palms healthy and attractive. Make sure you choose a specially designed fertilizer that has all nutrients in slow release form.  Look for an analysis such as 8-2-12-4 (Nitrogen-Phosphorus-Potassium-Magnesium).  Also read further on the label for Polymer Coated Sulfate of Potash, Magnesium Sulfate (Kieserite), and Chelate (Iron EDTA).  These are the forms of nutrients that will be beneficial to your palms.

Look in the area ‘Derived From’ (outlined in blue) on your fertilizer label to find the forms of nutrients. Photo by Dr. Monica Elliott, US/IFAS Extension.

If you have a mixed landscape where the palms are planted in the lawn, be sure to keep all lawn fertilizers out of the root zone of the palms. Lawn fertilizers do not have the correct forms of nutrients for palms. Remember also that palms roots extend many feet beyond the palm canopy so your ‘no lawn fertilizer zone’ may be past the mulch ring.

The recommendation from the University of Florida is 1.5 pounds of fertilizer over a 100 square foot area. Broadcast this on top of the ground and lightly water after application.  In North Florida, you will likely apply the correct palm fertilizer about at least two times in May and end of August or 1st of September.  If you are not able to use a palm fertilizer with the correct form of slow release nutrients, it is best not to fertilize palms at all.

Know How to Choose Florida-Friendly Plants

One of the main Florida-Friendly Landscaping principles is to plant the right plant in the right place. In Florida, not only does this apply to the zone you’re in, soils you have, and light conditions in your garden, but also ensuring that invasive, exotic plant species are not used. While most of us have heard about invasive, exotic plants – those that invade and disrupt our unique natural habitats – some may not know where or how to find out which plants are, in fact, invasive and exotic. Some of the more famous invasive, exotic plant species, such as kudzu and hydrilla, are familiar to us and we may have an idea of a plant in our garden that is “aggressive”, but how do we know for sure? Since only a handful of the worst invasive, exotic plants are legally prohibited from being sold, how do we know if a plant we are considering purchasing at our local nursery or another plant already in our gardens is an invasive, exotic? A quick internet search for Florida invasive plants gets you various sources of information. How do you choose which to use?

The unique habitats of Florida need our help. Prevent the spread of invasive, exotic species by planting Florida-Friendly plants. Source: Mark Tancig/UF/IFAS.

Fortunately, the researchers at UF/IFAS want you to be able to find the best information in one spot – the UF/IFAS Assessment of Non-Native Plants in Florida’s Natural Areas. This site systematically reviews individual plant species and provides a recommendation as to whether it should be used in North, Central, or South Florida landscapes. Many landscape plants have been reviewed – over 800 – and more are added to the site as reviews are completed. The UF/IFAS Assessment also reviews cultivars of known invasive, exotic plants to ensure that they are sterile and will not revert back to their wild type or hybridize with known invasives, or even closely related native species.

The UF/IFAS Assessment is a simple, convenient source for deciding if a plant should be used in your Florida landscape.

To use the site, simply visit the main web address – assessment.ifas.ufl.edu – and begin typing in your plant name in the search bar. You can begin spelling the scientific or common name and it will start showing possible results as you type. Once you select the plant you’re interested in, it will take you to a new page with photos of the plant, some general information, additional links, and, most importantly, the assessment conclusion for each zone. The conclusion will be one of the following:

  1. Not considered a problem species at this time,
  2. Caution, or
  3. Invasive

Of course, if it’s not a problem, then feel free to use and share that particular plant. If it is a caution plant, then it may be used, but you will want to be extra careful in where you plant it. Those may be better suited as potted plants or planted in areas that are confined, to limit its potential spread. If it’s invasive, don’t plant it.

Caution plants are reassessed every two years while those that are not considered a problem species or are considered invasive are reassessed every ten years.

Another way to use the UF/IFAS Assessment is to filter all reviewed plants by various criteria you’re interested in. If you select assessments on the main page, it will lead you to a list of all reviewed plants. A filter button allows you to choose geographic zone, conclusion type, and growth habit, among some other criteria. This will create a list that can then be exported to a Microsoft Excel table.

As you can see, UF/IFAS is trying to make it easy for you to determine which plants can be used in the landscape without potentially spreading and causing disruption to our unique natural areas.

If you have any questions about individual species that have or have not been assessed, contact your local County Extension Office.