Deflating false landscape lore
Many popular garden suggestions have no basis in fact.
Stop adding gravel to containers and sand to clay soil.
Start watering drought-resistant plants.
Like Mount Olympus or ancient Egypt, your home garden is the setting for many compelling, widely circulated myths that ultimately have no basis in fact. Unlike the mythologies developed in oral and literary traditions, these garden myths neither enlighten nor stir the imagination.
They simply mislead you on your journey to the perfect landscape—in the most benign cases, wasting your time and money, and at worst, actively harming your soil and flora. Come with us, as we bust 12 of the most widespread and incorrect tall tales of the garden and set the record straight.
Gardeners are often told they must add gravel, or some other kind of coarse material, to the bottom of pots and other planters to allow for drainage and discourage root rot. Never mind that this is unnecessary since any container adequate to planting will have drainage holes; gravel is not just unnecessary but harmful.
When it’s piled up at the bottom of a container, the gravel pushes pooled water upwards, slowing drainage and encouraging rot. If you’re having drainage issues with your containers, try a potting soil that includes a coarser material, like bark—or mix in perlite.
When a plant is said to be drought tolerant it means that it can survive throughout a summer without additional watering from the hose. This doesn’t mean that it never needs water—or that it’s healthy to go entirely without supplemental watering.
In the first year of their life, drought-resistant perennials require a fair amount of water to establish their roots. Make sure the soil is moist, but don’t overwater. After that, a once-monthly shower from the hose should be plenty.
Whether they’re produced by Mother Nature or research chemists, pesticides are designed to kill. Made with naturally occurring poisons, organic pesticides can pose serious harm to the lives of your family, pets, and beneficial garden critters if used incorrectly or accidentally consumed.
Store and place pesticides safely, opt for the least toxic active ingredients—insecticidal soap and Bacillus thuringiensis are good choices—and carefully follow the directions on the label.
Remember too that pesticides cannot resolve chronic issues; if you find yourself relying on them frequently, you may be choosing the wrong plants for your garden, or making some kind of error in planting or caring for them.
Because clay is composed of very fine, dense particles, the soil can be difficult to work with and is prone to waterlogging. In some regions, a popular garden myth has it that adding sand will make it easier to work with and faster to drain.
There’s a kind of intuitive logic here—sand is loose and easy to dig—but the fact is that the combination is more likely to exacerbate the very problem it’s trying to solve. Adding compost—to a hole or as top-dressing—is your best bet for making clay easier to work with.
When you picture a sapling, you probably imagine it supported by guy-wires between two stakes. In many cases, however, this will hinder rather than help a tree’s development. It can be necessary for trees planted in highly windy areas, on slopes, or for particularly top-heavy tree species—but it can prevent them from growing as strong as necessary.
Staking can result in taller trees, but it harms the trunk and weakens it. If you’re in a situation where staking is unavoidable, make sure the wires are short and of a soft and pliable material (like a garden hose), and remove the stakes no more than six months after planting.
Popular garden myths—and a host of specially branded products—has it that adding paint or tar to a fresh tree wound after pruning is necessary to ward off infection and infestation.
Unfortunately, many tree wound dressings do more harm than good by slowing a tree’s natural healing process and trapping moisture near the wound, encouraging fungal growth.
While these products have fallen out of favor with most of the profession, some arborists maintain there are one or two exceptions, advising use of the sealant on oak trees in parts of the Eastern U.S. that experience oak wilt, as well as some birch trees.
If you might be in one of these situations, seek the advice of a local arborist. In nearly every other case, the best way to prevent long-term damage is to prune correctly with a sharp tool and to do so at colder times of the year when there are fewer insects and fungus has a harder time growing.
Many trees are sold in balled-and-burlapped form, with the root covered in soil and bagged up—but contrary to the advice given at some nurseries, removing the layer of material and soil before planting it in your yard will not cause the root ball to collapse.
In fact, failing to do so could prevent the tree from effectively establishing itself at all. The root ball soil might be very different from your own, and combining the two can slow water movement. Additionally, removing the soil is your only opportunity to inspect the roots and fix any defects.
There are lots of bone meal products on the market, but they serve no helpful purpose in most home gardens. Bone meal provides soil with phosphorus and calcium, which rarely need to be supplemented in non-agricultural soil.
Too much phosphorus can actually prevent the growth of mycorrhizal fungi, which is necessary for healthy root growth. There are much better fertilizers for the home gardener.
There are very good reasons you should water your plants early in the morning when the sun is low. It prevents the water from evaporating too rapidly and thus dehydrating soil and wasting resource.
But there is no fact to the idea that water droplets on leaves will magnify the sun’s rays and burn them. Applying very cold water to a very hot leaf can cause some damage. But in most cases, if you don’t get a chance to bring out the hose earlier in the day, a mid-day spritz will not harm your plants. Generally, you should be watering the soil rather than the leaves.
Many children are taught that earthworms possess such strong regeneration capabilities that cutting one earthworm in half will produce two separate living earthworms. While earthworms are able to recover from some serious damage, they possess a nervous system that must remain intact to survive.
In the best-case scenario, you might end up with one injured earthworm and one dead one, but you’re most likely to find yourself with one divided earthworm corpse. While it’s impossible to avoid ever injuring these beneficial creatures, deliberately cutting them is unnecessary and bad for your soil.
Because black walnut trees have roots that emit juglone, a substance that can inhibit plant growth, the idea has emerged that it will kill anything planted in close vicinity.
It’s true that this substance will make it difficult to grow some species nearby, but there are plenty of others that will do just fine in a black walnut-adjacent landscape. The full list will depend on your local climate, but common options include begonias, daffodils, foxglove, impatiens, and tulips.
The last garden myth we’re debunking is one you’ll be happy to hear. Bagging or raking up grass clippings after mowing is not only a waste of time and energy—it deprives your lawn of a free source of soil-enhancing nitrogen (especially if you use a mulching mower).
It was once thought that a layer of clippings would contribute to the appearance of thatch, but this idea is no longer supported.
