by Daniel J. Leonard | Sep 19, 2024
Problem areas in the landscape – everyone has them. Whether it’s the spot near a drain that stays wet or the back corner of a bed that sunshine never touches, these areas require specialized plants to avoid the constant frustration of installing unhealthy plants that slowly succumb and must be replaced. The problem area in my landscape was a long narrow bed, sited entirely under an eave with full sun exposure and framed by a concrete sidewalk and a south-facing wall. This bed stays hot, it stays dry, and is nigh as inhospitable to most plants as a desert. Enter a plant specialized to handle situations just like this – Yarrow ‘Moonshine’.
Yarrow (Achillea spp.) is a large genus of plants, occurring all over the globe. To illustrate, Common Yarrow (Achillea millefolium) is native to three different continents (North America, Europe, and Asia), making it one of the most widely distributed plants in the world. And though it was commonly grown and used in antiquity for medical purposes (the genus name Achillea is a reference to Achilles, who supposedly used the plant as a wound treatment for himself and his fellow Greek soldiers), I and most of you are probably more interested in how it looks and performs in the landscape.
‘Moonshine’ Yarrow foliage.
All species of Yarrow share several ornamental traits. The most obvious are their showy flowers, which occur as large, flattened “corymbs” and come in shades of white, pink, red, and yellow. I selected the cultivar ‘Moonshine’ for my landscape as it has brilliant yellow flowers that popped against the brown wall of the house. Equally as pretty and unique is the foliage of Yarrow. Yarrow leaves are finely dissected, appearing fernlike, are strongly scented, and range in color from deep green to silver. Again, I chose ‘Moonshine’ for its silvery foliage, a trait that makes it even more drought resistant than green leaved varieties.
‘Moonshine’ Yarrow inflorescence.
If sited in the right place, most Yarrow species are easy to grow; simply site them in full sun (6+ hours a day) and very well drained soil. While all plants, Yarrow included, need regular water during the establishment phase, supplemental irrigation is not necessary and often leads to the decline and rot of Yarrow clumps, particularly the silver foliaged varieties like ‘Moonrise’ (these should be treated more like succulents and watered only sparingly). Once established, Yarrow plants will eventually grow to 2-3’ in height but can spread underground via rhizomes to form clumps. This spreading trait enables Yarrow to perform admirably as a groundcover in confined spaces like my sidewalk-bound bed.
If you have a dry, sunny problem spot in your landscape and don’t know what to do, installing a cultivar of Yarrow, like ‘Moonshine’, might be just the solution to turn a problem into a garden solution. This drought tolerant, deer tolerant, pollinator friendly species couldn’t be easier to grow and will reward you with summer color for years to come. Plant one today. For more information on Yarrow or any other horticultural question, contact your local UF/IFAS County Extension Office.
by Daniel J. Leonard | Aug 12, 2024
Despite being a near-perfect ornamental for the Panhandle, Crape Myrtle is often misused. Though there are dozens of commercially available varieties in all shapes and sizes, many people choose the wrong one for their yard. The most commonly sold cultivars ‘Natchez’ (white flowers), ‘Muskogee’ (pink flowers), and ‘Tuscarora’ (watermelon red flowers) – all three attain mature heights more than 20’ – are almost always too large for siting near a house or other structure and are often out of scale with landscapes. The simple solution to making the best use of Crape Myrtle in smaller yards (certainly not dramatic pruning – Crape Murder is among the worst landscape sins), is to select a smaller growing variety and ‘Tonto’ is a personal favorite in this category.
‘Tonto’ Crape Myrtle, one of the selections that emerged from Dr. Don Egolf’s Crape Myrtle breeding program at the U.S. National Arboretum over 50 years ago, is among my favorite Crape Myrtle varieties for several reasons. First, Tonto’s fuchsia hued flowers are as vibrant as flowers come; they practically glow in the landscape. The flower show lasts for several months and are a valuable food source for pollinators, bees in particular, in the late summer when few things are blooming. Tonto also is a relatively slow grower that only reaches about 10’ tall and wide at maturity. This allows the variety to be exceedingly versatile in landscapes as it can be used in the background of planting beds, as a specimen plant, limbed up as a small tree in open areas, or even placed in very large containers. Finally, beyond just the flower show and ideal size, ‘Tonto’ has uniquely attractive, cream colored, exfoliating bark and reliably attractive fall foliage. Both these features add interest to landscapes, even when ‘Tonto’ isn’t flowering.
Though ‘Tonto’ sports many unique qualities, it shares many other excellent traits and growing preferences with its Crape Myrtle kin. For best results growing any Crape Myrtle, trees should always be sited in full sun, at least 6-8 hours a day. Shading will result in greatly reduced flowering and lanky plants. Regular watering during the first year after planning while trees are becoming established is helpful, as is periodic fertilizer application. Once established, ‘Tonto’ and all other Crape Myrtles are exceedingly drought tolerant and can get by on their own with minimal inputs from gardeners.
If you’ve been struggling with a Crape Myrtle that has outgrown its site or thinking about planting a new Crape, I’d encourage you to give ‘Tonto’ a look. It’s an outstanding shrub/small tree, will reward you with flaming fuchsia flowers and smooth cream-colored bark each summer, and will never outgrow its space. Plant one today! For more information on growing Crape Myrtles or any other horticultural topic, contact us at the UF/IFAS Calhoun County Extension Office. Happy gardening.
by Daniel J. Leonard | Jul 3, 2024
While the Florida Panhandle isn’t considered a true tropical climate, now that the summer rains have started, it sure feels tropical outside. To create high performing colorful containers in these conditions, it’s wise to pick plants that hail from tropical climes – one of my favorites is Crossandra (Crossandra infundibuliformis).
Native to tropical Sri Lanka and India, Crossandra is built for hot, humid conditions. An evergreen subshrub growing about 3’ tall in its native range, Crossandra sports glowing orange flower clusters held high on stems that rise above deep green, glossy foliage – a very striking combination. These showy orange flowers arrive once temperatures heat up in the early summer and continue emerging en masse until cool nights stop the show in fall. While deadheading spent flowers can enhance Crossandra’s free-flowering nature, I haven’t found it totally necessary to ensure consistent flowering. In addition to being beautiful, Crossandra’s flower clusters are also attractive to a wide variety of pollinators, including butterflies and dragonflies.
Crossandra growing in partial shade on a patio. Photo courtesy of Daniel Leonard.
Adding to Crossandra’s appeal, the species couldn’t be easier to grow if you give it the right conditions. Crossandra prefers to be sited in areas that receive ample sunlight but also get a reprieve from the hottest afternoon rays. This year, I grew one on a deck that receives sun from about 10 am – 2 pm and is then provided filtered shade from a large tree the rest of the afternoon; these conditions seem to be ideal. Crossandra performs best in moist, well-drained soil, making potting mix an excellent option. Daily watering in the summer combined with our (hopefully) frequent rainfall in July and August keeps it wilt-free. I also apply slow-release fertilizer at planting and then supplement with liquid fertilizer periodically throughout the summer. This, combined with regular irrigation, promotes healthy, vigorous growth, and allows the flower show to continue uninterrupted until cool weather finally draws the curtains.
Crossandra is a versatile plant in container gardens, shining in either the role of filler in larger containers or as a solo specimen plant in its own container. In mixed containers, play off of Crossandra’s orange flowers with partial sun foliage plants like Coleus, Elephant Ears, or Hawaiian Ti, or flowering annuals like Browallia ‘Endless Illumination’, Torenia (Wishbone Flower), Blue Daze, or Purple Heart Plant. While Crossandra does well in mixed containers, as a UF graduate, I prefer to stick it in my favorite blue pot for an orange and blue Gator themed solo container!
Regardless of how you choose to incorporate Crossandra into your garden’s design, it will reward you with summer-long orange flowers in a low-maintenance package. Simply place it in morning to early afternoon sun, give it ample water and adequate fertilizer, and enjoy this Florida Friendly Landscaping approved species. Plant one today!
For more information about Crossandra or any other horticultural topic, contact your local UF/IFAS County Extension office.
by Daniel J. Leonard | Jun 13, 2024
For those of us that don’t have the best landscape conditions or the time, money, or inclination to invest into a vibrant yard display of annual flowers, growing our flowers in containers is a great option! Growing in containers has several advantages over growing flowers in the ground. It gives gardeners control over the soil, fertility, and water conditions that the plants are grown in and the ability to add pops of color/texture anywhere – in an existing planting bed, patio, deck, porch, or even indoors. Let’s explore some simple tips to create containers that will offer low-maintenance explosions of color all summer long.
The easiest way to create full, colorful containers is by using the design scheme known as the “thriller, filler, spiller” arrangement. This design first utilizes a dramatic “thriller” in the back of the container, usually a plant that has a taller, upright growth habit and striking flowers or foliage. Commonly used thrillers are plants like Purple Fountain Grass, Salvia, Canna, and Hawaiian Ti. Next come the fillers. Fillers are plants that possess a mounding habit and generally provide the floral firepower in the container. Popular fillers include Vinca, Begonia, ‘Diamond Frost’ Euphorbia, Lantana, Pentas, Impatiens (for shady containers), and even foliage plants like Coleus, Caladiums, and Ferns. Finally, spillers round out the containers by “spilling” over the sides. These are typically vining or trailing plants and add a final dramatic touch to the overall container style. Some of my most-used spiller plants are Creeping Jenny, ‘Silver Falls’ Dichondra, ‘Gold Dust’ Mecardonia, Torenia (aka Wishbone Flower), and Sweet Potato Vine.
Example container using a thriller (Purple Fountain Grass), filler (Celosia), and spiller (‘Silver Falls’ Dichondra). Photo courtesy of Daniel Leonard.
Will all those plant options, how does one choose plants to combine in containers? When perusing the nursery to pick thriller, filler, and spiller plants, all you need to remember to be successful is the basic layout of the color wheel and the phrase “right plant, right place”. Knowing the color wheel is important because some colors look better than others in combination! For instance, most classic color combos are known as “contrasting colors”, just meaning opposite each other on the color wheel – think the Orange and Blue of the Florida Gators or the Purple and Gold of the LSU Tigers. It’s hard to go wrong pairing plants of contrasting foliage or flower colors. Another option is to use different shades or hues of the same color, this is known as a monochromatic color arrangement. Monochromatic arrangements create a stunning punch of color and can even be used to highlight colors or features around the container, like the brick or siding color of your home.
After choosing your color palette, it’s critical to make sure you have the right plant in the right place. For container gardening, this just means pairing plants with like needs. For instance, you wouldn’t want to grow shade loving Impatiens in the same container as sun loving Purple Fountain Grass. Likewise, pairing a succulent with a heavy water user like Coleus is a bad idea. Combine plants with like growing condition preferences and you’ll save yourself a major gardening headache!
Maintaining your summer containers is also relatively easy. At planting, fertilize with a slow-release fertilizer like Osmocote or other similar product at the label rate and water in. After the first month or so, I begin supplemental fertilizing every couple of weeks with a liquid fertilizer. As your container grows, the days get hotter, and there are more roots to suck up water, your watering frequency will increase from once every couple of days to every day, and, on very hot days, twice a day (morning and late afternoon/evening). All this watering and fertilizing sounds like a lot of work, but I enjoy getting out and spending a few minutes with my plants! It’s a great way to start your day/wind down after work and allows you to spot any issues before they become major problems!
Gardening with containers is without a doubt the easiest way to create summer long color on your deck, patio, or landscape. Giving us the ability to control soil, water, sun, and fertilizer conditions, growing our annual color in containers removes many of the variables that makes gardening difficult and provides pops of color and texture in any setting – design and plant a few containers this summer! For more questions about container gardening or any other horticultural topic, contact us at the UF/IFAS Calhoun County Extension office. Happy gardening this summer!
by Daniel J. Leonard | May 9, 2024
In the last couple of weeks, I’ve had multiple questions regarding trees and shrubs that aren’t looking too hot. These types of calls are common this time of year – it has gotten hot and dry, and plants have fully emerged from winter, causing issues that have been hiding under the surface during the dormant season to manifest as crown or branch dieback. While there are a wide variety of things that can cause dieback, in most cases a little detective work can help pinpoint the issue. Let’s look at a few of the most common causes of dieback and some corrective measures that may help restore the plants to health.
The first thing to do when you notice a plant in decline is nothing. Don’t try and oversaturate it with water. Don’t run out and dump a bunch of fertilizer around it. Many times, these panic measures exacerbate the stress the plant is already under. Instead, I encourage you to give us a call at your local UF/IFAS County Extension Office. We can likely help identify the cause of the problem through a site visit to your property or by you sending us diagnostic photos of the plant with a description of what’s been going on with it – the more information you can provide about the plant and the management practices it has experienced, the better (you can email diagnostic images/information to d.leonard@ufl.edu).
The most common cause of tree/shrub dieback that I see arises from improper planting practices. Most landscape plants should be planted at or just above the surrounding soil level, preferably where the topmost root arises from the trunk. To accomplish this, planting holes should be dug slightly shallower than the rootball’s height and about twice as wide. Planting any deeper than that is probably too deep and can cause problems like trunk and root decay, which lead to crown dieback. Unfortunately, once a plant is planted too deep, it cannot be corrected other than digging up and replanting at the proper depth, which may or may not be possible depending on the size of the tree. Another common issue that can arise after planting is girdling roots. This occurs when plants are grown in plastic containers and develop a root system that circles the inner wall of the pot. If not trimmed, the plant’s root system will continue to grow in this manner, eventually encircling the plant’s trunk, cutting off water and nutrient flow, and leading to crown dieback. Fortunately, this condition can be prevented by cutting, removing, or redirecting these roots at planting.
The next most common cause of plant dieback occurs due to soil disturbance by people. It’s easy to forget but the root zone of trees and shrubs can reach out several times farther than the plant is tall and is easily damaged. Disturbances to the root zone from digging or trenching near trees or compaction from prolonged vehicle travel over the area cause damage that might be slow to appear but can lead to plant decline. If you are doing construction or building near a shrub or tree, try to keep digging machinery as far out of the root zone as possible and avoid repeatedly parking or driving vehicles over the root zone area. Like below ground root damage, trunk damage that occurs from injury by string trimmers, mowers, or animal feeding activity can all disrupt the flow of water and nutrients in plants and prove deadly. There is no cure for this type of damage, so employing physical barriers to prevent damage is key.
The last major stress is environmental in nature and is caused by a water imbalance – either too much or not enough. Dry soil conditions during the planting and establishment phases (first several years after planting) should obviously be avoided if possible – keeping the developing rootzone moist and allowing plant roots to establish in their native soil is critical. Too much water can also cause problems for trees planted in poorly drained soil. Excessive moisture leads to root diseases, which ultimately presents as dieback in the canopy. If planting in an area that tends to stay wet, select a species of plant adapted for that sort of site – some species are more tolerant of “wet feet” than others. While many people expect disease and insect damage to be the cause of an unhealthy plant, they’re often not the biggest culprit and, if they occur at all, are generally secondary to one of the above issues.
For more information about crown dieback or declining landscape plants, contact your local UF/IFAS County Extension office. Happy gardening!
