Plants become aware that fall is approaching well before humans. For those of us who work with plants, we think of fall as beginning well before coffee shops start offering pumpkin spice lattes. Best to get started on your fall gardening tasks immediately!
Get leaves up as soon as they start falling
The process of leaves falling from trees is called abscission and it begins before the leaf actually falls from the tree, happening in three steps: remobilization, protective layer formation, and detachment. During remobilization, the tree extracts nutrients from chlorophyll, degrading it, and causing the leaf to change color by leaving carotenoids (orange, red, and yellow plant pigments) in place but destroying the chlorophyll. Nitrogen in particular is often bound up in chlorophyll and the tree needs that nitrogen to get through the winter.
There are two common misconceptions among gardeners: 1. Plants don’t need nitrogen in winter and any nitrogen they get will cause them to put on new growth and become vulnerable to winter cold; 2. Leaves allowed to decompose in winter will become a good source of nitrogen in the spring.
First, though high nitrogen inorganic fertilizer with no time release component in late summer or early fall may cause a burst of new growth in some circumstances, the concern is usually overblown. Winters in Memphis tend to be mild and approach gradually, and plants need nitrogen in varying amounts year round. Second, as we learned when looking at the process of abscission, much of the nitrogen is sucked out of leaves by the plant before leaf drop.
Accordingly, allowing leaves to sit under trees and around shrubs all winter, year after year, as they do in forests, is not good for the plants. To see what happens in the “natural state,” walk through The Old Forest in Overton Park and notice how a large percentage of plants in an actual forest are in various states of deterioration and decay. Forests survive, often, more by their prolific seed drop rather than because conditions are ideal for individual plants. New plants are ever replacing old plants, giving the illusion of consistency.
So, start getting up leaves as soon as they start falling! Blow or rake leaves out of beds regularly, maybe onto your turf grass, and then run over them with a lawn mower, before the leaf volume gets so great that it will choke your mower. Then bag the shredded leaves and place them curbside for municipal pickup (shredding them first will reduce the number of bags needed tremendously and speed their decomposition in a landfill) or put them in your compost bin. Remember, though leaves alone are poor sources of nitrogen, composted leaf mulch, mixed with other compost, can be good spring fertilizer or a component for a custom soil mix.
Allowing leaves to accumulate excessively on top of the lawn will create the perfect breeding ground for fungal problems. Raise the mower blades to 3-4 inches in late summer and let the mower suck up some leaves and leave a small amount of shredded leaves in the turf.
Plant fall annuals for color
It would be unwise to plant an entire yard in annuals, given the expense. But, every yard should have designated spots for seasonal color. Some of the best annuals for planting in the fall include pansies, violas, mums, snapdragons, swiss chard, and kale. Urban Earth Garden Center has a full selection in stock right now. To see more of what’s in stock, check out our slideshows on our facebook page, Urban Earth by Greg Touliatos.
To really learn about fall color, join us for a free class on the subject (“Fall Annuals and Fall Bulbs for Your Garden”) by David Levy, Greg Touliatos, and John Jennings on Saturday, October 14, 2017 at 1pm.
Put down a granular pre-emergent
Put down a granular pre-emergent in both the spring and fall to stop weed seed from germinating. We like Hi-Yield Turf & Ornamental Weed & Grass Stopper Containing Dimension. One bag will cover up to 3,500 square feet of planting beds or up to 5,000 square feet of turf. Though it is not a cure-all, it will form a chemical barrier that will prevent a large percentage of weed seed from germinating and becoming fall annual weeds. Preen is the most widely known pre-emergent among consumers but we like this product better.
Put down seed for cool season plants
Apply fescue seed, winter rye seed, or “fall cover crop” mixes to your turf in September and October for best results.
Fescue is often described as a shade grass but a more accurate description is a cool season grass that does well under the canopies of deciduous trees. Zoysia and Bermuda are warm season grasses, meaning that they engage in photosynthesis in the spring and summer and go dormant when temperatures drop. In contrast, cool season grasses, like fescue, engage in photosynthesis, coming alive, after leaf drop. The fact that fescue is not a “shade grass” is important because it would not do well under the canopies of evergreen trees. (Note: Creeping red fescue is a genuine shade grass but is not recommended because it has zero tread tolerance; even a squirrel walking across it will kill it, the reason we don’t carry the “deep shade” fescue mixes some other garden centers carry.)
Also, remember that fescue is only barely tolerant of our heat. Hence, it thins in late summer and needs to be over-seeded at least once per year, every fall, and preferably again in late winter, around the time crocuses start coming up or shortly thereafter, to create a lush look. How to install fescue is beyond the scope of this article but come see us and we will be happy to explain it!
Fall cover crops are plants that do well in cooler temperatures and are special because of their nitrogen fixing qualities. They are generally, with some exceptions, annuals, meaning they won’t come back again after their season completes.
By nitrogen fixing qualities, we mean that they have a symbiotic relationship with certain bacteria in the soil that allows the plants to pull nitrogen directly from the ambient air for their benefit and the benefit of plants around them, releasing the nutrients into the soil when they die at the end of their season. These plants include legumes like red clover (annual) or durana white clover (perennial), both of which we carry as stand-alone products and in mixes. For a better understanding of how to use fall cover crops to improve the look and health of your turf, please visit our store.
Fall is the time to plant bulbs like daffodils, crocus, and tulips for winter to spring beauty. This year, we will be receiving our bulb order from Devroomen, one of the best suppliers of bulbs in the world, in the first or second week of October. Although you can install bulbs well into January or even, in some cases, February, if you wait too long after they arrive at our store to buy them, you will have fewer choices. They go quickly!
This author likes to install bulbs the Friday, Saturday, or Sunday after Thanksgiving as a family activity. Installing bulbs too early can mean that they start coming up too early, making the new growth vulnerable to the destructive effects of a hard freeze. After Thanksgiving, the chances of a false spring are much less.
Generally, in Memphis, daffodils and crocuses are perennials, meaning that they will come back every year, while tulips are annuals. Though daffodils and crocuses are technically perennials here, they have an ephemeral nature in that they don’t seem to come back every year. In my experience, in any given year, 80% of my daffodils will pop up and bloom, but it won’t be the same 80% each year. Crocuses are similar in that regard.
Crocuses, my favorite bulbs, are often overlooked as options by gardeners. But, they do well under the canopies of trees, whereas daffodils really need more sunlight to come back up again in future years. Further, crocuses come up earlier than most everything else, often seen pushing up through ice and snow as a beautiful harbinger of spring. Though the metaphor may be nearly cliche, gardeners are like wine drinkers. New wine drinkers like sweet and fruity wines, like a pinot grigiot, sauvignon blanc, or even an after dinner sweet port. But, as they mature in their appreciation of wine, they move onto the cabernets and the merlots.
Bulbs are like that in that new gardeners tend to gravitate towards the tulips, mere annuals in our climate, but bright and showy, while crocuses are generally something appreciated by more experienced gardeners for their subtlety.
One thing to keep in mind about bulbs is that the photosynthates absorbed by the plants coming up from the bulbs this year determine their success in the following year. So, if you plant them in too little sunlight, they will likely come up fine the first year but will perform poorly, if at all, the following year. For the same reason, it is important not to cut your plants back after the blooms are spent until the plants themselves begin to deteriorate to give the leaves as much time as possible to create and store photosynthates (a nutrient that can only be made when light is being absorbed) to ensure a good outcome for the next year.
Remember, all bulbs require a certain number of hours of chill time in order to be successful. All of our bulbs come pre-chilled. It is for this reason, perhaps, that after mild winters in Memphis, fewer daffodils and crocuses come up but come back in subsequent cooler years.
Between the time that you buy bulbs and the time you plant them, keep them in a paper sack in a cool dark place, ideally at a temperature below 70 degrees Fahrenheit.
Plant trees and shrubs
Although good gardeners can plant trees and woody shrubs any time of the year, there is no question that the best time to do so in Memphis is the fall. Temperatures are moderating, slowing soil evaporation, and the rainy season is beginning, giving new plants, which always begin with shallow root systems, a much better chance of survival and allowing them to develop a wide and deep root system before Memphis’s drought period in July and August. Further, many plants go into dormancy, a self-protective mode where the focus of their growth shifts from their canopies above ground to their root systems below ground, meaning that they develop root systems faster in the fall than they would any other time of the year.
But beware, a well-managed nursery should not be too soft with its plants in winter. All plant nurseries wrap their greenhouses in plastic in winter, but good nursery managers are also careful to properly harden their plants off. Tender new canopy growth in plants is a point of vulnerability when a freeze hits. So, if you buy plants from a garden center that has kept its greenhouses too warm, causing them to put on lots of pretty new growth, you may have a dead plant a few weeks after you put it in the ground. Hardening off plants and keeping them hardened off until winter has ended is an art, a process
Greg Touliatos personally supervises and monitors at Urban Earth Garden Center, entrusting it to no one else.
For ideas on trees to plant in your yard, see the article, “Best Trees for Memphis,” or, better yet, come talk to us in the store and we can look at the options together. For best results, email the street address and photos of the area where you want to plant ahead of time to firstname.lastname@example.org. If you there is a plant you want but think we might not have in stock, email us to request it. Be sure to put “Plant Request” in the subject line and we will confirm receipt of your email and let you know if and when we are able to find it, by email.
Transplant trees and woody shrubs
For the same reason fall is the best time to install woody plants in Memphis, it is really the only time to transplant woody plants in Memphis. The very act of transplanting causes significant damage to a plant’s root system, reducing its ability to take up moisture and nutrients from the soil. Transplanting is too complicated in scope to address this article, but please visit us for advice on transplanting.
In particular, this author recommends that you use Fertilome Root Stimulator. Fertilome Root Stimulator contains auxins, plant hormones that help stimulate new root development, and other nutrients needed for plants with damaged root systems. Be careful using other fertilizers when transplanting, because recently transplanted specimen are particularly vulnerable to burn from excessive fertilization.
Apply time release 12-6-6 fertilizer in spring and fall, like the Hi-Yield Growers Special that we carry, or an organic alternative like Happy Frog by Fox Farm. Apply soil sulfur to all of your woody plants, except boxwoods, especially azaleas, hydrangeas, and hollies. (Note: If you are regularly using Happy Frog Fertilizer for Acid Loving Plants there is no need to apply soil sulfur, in my view.) Apply lime to boxwoods every other year or so to raise the ph, a measure of soil alkalinity or acidity, since boxwoods are about the only plant commonly used in ornamental beds in Memphis that likes a more alkaline soil, preferring a slightly higher ph than other woody plants. Let us guide you in the specifics of applying these products when you visit.
Many gardeners are shy about pruning or trimming plants too late in the year. Pruning and trimming can stimulate new growth, and as already explained above, new growth makes the entire plant more vulnerable to cold damage. But, if you’re in the garden already, in Memphis, it won’t hurt and may very likely help to do a little careful pruning. At least prune any deadwood out of your woody plants, selectively thin plants with dense growth by removing branches, and prune a third of the canopies of your roses back in the fall (You will prune another third of the canopy of your roses back right after Christmas, before the winter winds get especially strong). Do not do any wholesale shearing with a power trimmer to shape as this will definitely stimulate new growth!
When you prune, always use high quality bypass pruners and be sure to disinfect your pruners between plants with a 10% solution of bleach to prevent disease spread. We carry the industry gold standard for bypass pruners, Felco, but we also carry less expensive but still excellent models by Corona and Tierra Pro. Anvil pruners, which we do not sell at Urban Earth, tend to mash the branches rather than cleanly cutting through them, whereas bypass pruners make healthy cuts with fewer entrance points for plant disease. (I have yet to come across a single good reason for a gardener to own a pair of anvil pruners.) Make sure your pruners are sharp too for the cleanest cuts. If you’re not sure about the pruners you currently own, come see us for guidance and advice in learning to maintain them.
Fall is a great time to go full on Martha Stewart! It’s easy to cut flowers in the spring and summer and stick them in water. But, fall both requires and allows for more creativity. For more information, google “creating fall centerpieces for tables” and a wealth of information will come up. One of our employees, Martha “Martha Stewart” Garriott, is particularly talented and will be happy to help you pick out the perfect vessel and find seasonally appropriate cuttings and elements to complete the centerpiece.
Fall is a great time to read, study, and sharpen your knowledge as a gardener. And, there is no better
place than Urban Earth Garden Center to help you along this journey. We have a clever selection of books, knowledgeable employees who give good advice, a regular schedule of free classes in our education annex, outside speakers, and hands on assistance and guidance. Follow us on Facebook to find our seminar schedule or look for it in our blog section, updated a few times each year; read our blog; subscribe to and read our emailed newsletter by emailing email@example.com and requesting that you be added or messaging us on our fb page; and email me with questions and photos (firstname.lastname@example.org).
The author, John Jennings has been manager of Urban Earth Garden Center since June 1, 2016. Before that he was a self-employed landscaper for 8 years, having previously worked as both a real estate lawyer and a drug counselor in previous lives. He grew up in the South Carolina low country, learning to garden in the fertile soil of Copes Island, a small barrier island near Beaufort, in Jasper County, the famed land of Pat Conroy. He was taught the basics of planting by his step-father, Wade, his mother, Melissa, and his father, Karl. Though both of his parents grew up in Memphis, and he spent vacations visiting his maternal grandparents, Richard and Diana Allen in Memphis, he did not become a resident of the city until he finished college in 1994. He left South Carolina at the age of 14 to attend The McCallie School for Boys, in Chattanooga, Tennessee, graduating in 1990, before getting a degree in English from the University of Richmond, in Virgina,in 1994, finally graduating from the University of Memphis Law School in 1997. He has a 10 year old son named Henry. If you read this blog entry, please email the author at email@example.com and let him know what you think.