Today we explode some common garden myths:
• Myth: A bleach solution is the best choice to sanitize pruning tools.
A bleach-water mixture (1 part bleach to 10 parts water) is commonly recommended to clean pruning tools to help prevent the spread of diseases in the garden. While bleach will kill plant pathogens like fungi or bacteria, it is also corrosive and can damage pruning tools. Better choices are rubbing alcohol or household disinfectants such as Lysol. Wiping the pruners with a clean rag after soaking or dipping in a proper cleaning solution will help kill even more disease-causing organisms.
• Myth: Stressed plants will be helped by the addition of fertilizer.
Fertilizer isn’t plant food; it’s more like a growth stimulant. Giving a stressed plant incentive to grow is something like giving a tired toddler an energy drink — it’s backward thinking. The fertilized plant will be stimulated to produce new tissue but at the expense of stored reserves that could be better used to produce defensive chemicals. These chemicals help the plant ward off attacks by insects and disease pathogens. A better approach to help a stressed plant is to find and resolve the source of stress, if possible.
• Myth: Black-eyed Susan (Rudbeckia fulgida) is a butterfly magnet.
Our native perennial black-eyed Susan is attractive in full flower with mounds of yellow flowers that can stay in bloom for weeks in late summer. The cultivar ‘Goldstrum’ was named Perennial Plant of the Year in 1999, and it is often heralded as a magnet for butterflies and other pollinators. In reality, however, this plant is more of a pollinator desert, rarely visited by any six-legged creatures. Plant ‘Goldstrum’ for the flowers, but for the pollinators, plant goldenrod (one with manners, like ‘Fireworks’) or Joe-Pye weed.
• Myth: Suckers growing at the base of trees can be controlled by spraying an herbicide like Roundup.
This practice was actually undertaken by employees of a local landscaping company, presumably without their boss’s knowledge. A friend of mine witnessed the crab apple trees in his condo complex being sprayed at the base with Roundup. Since the suckers are part of the tree, the herbicide is taken directly to the tree’s roots. Don’t try this at home! The only way to manage suckers (notice I didn’t say control) is to prune them off at ground level. And repeat.
• Myth: You can’t get poison ivy in winter.
This myth comes up every so often in winter when I get a phone call from someone who has to go to the hospital for a serious rash, but the source of the rash can’t be determined. Doctors and other medical staff insist the rash couldn’t be caused by poison ivy because of the time of year. As I know from personal experience, it’s easy to get a case of poison ivy in winter. Since every part of the poison ivy plant contains the offending oil urushiol, digging out roots, pruning branches or handling fruit in winter is more than enough exposure to come in contact with the oil.
• Myth: Scratching the rash caused by poison ivy will spread the rash from place to place and from person to person.
When urushiol comes in contact with human skin, contact dermatitis often follows. While not everyone is susceptible, most people break out in a rash from this contact a day or so later. A tiny amount of oil is all that is needed to cause the reaction; it is said that the amount of oil on the end of a pin could cause 500 people to itch!
Once the oil has been removed from the skin, however, the rash cannot spread from place to place, even when blisters start to ooze. That’s not to say that a small amount of oil isn’t hiding somewhere, on clothing, the dog, pruners or the car steering wheel, causing continued outbreaks, but the problem isn’t spread from rash to rash.
• Myth: Adding soil amendments to the garden when first preparing the garden is enough; no further additions are necessary.
Over time, organic matter in the soil breaks down, particularly if the garden is regularly tilled. The yearly addition of about an inch of organic matter, such as leaf mold or compost, helps to keeps the soil workable and provides a healthy root zone for plants.
• Myth: Adding nails to the soil adds iron, and therefore keeps plants healthy.
Yes, some folks do add nails when they plant. When plants suffer from iron deficiency, it’s not because iron is lacking in the soil. When the soil pH is too high, iron becomes unavailable to plant roots. Save the nails for the roof, and have soil pH tested, making amendments as recommended based on the test results. Keep in mind, though, that raising soil pH over a large area is rarely practical (see the next myth).
Myth: Soil pH can be permanently lowered, making it suitable for acid-loving plants.
Soil pH is a lot like body weight: you may shed a few pounds, or perhaps gain a few on vacation, but chances are your body hovers around a certain weight (whether you’re happy with this scenario or not). Soil has a feature called buffering capacity, meaning it tends to return to a standard pH. It’s easier to raise the soil pH (by adding lime) than to lower pH. Even when the pH is lowered, the buffering capacity brings it back up, so any pH changes are temporary.
• Myth: Getting rid of grubs equals getting rid of moles.
Moles are carnivores, meaning they’re just as likely to eat earthworms as grubs. I have actually had people ask me how to kill all the earthworms in the soil so the moles have nothing to eat. Honestly, do you want to walk over a lawn that’s so toxic that nothing lives there?
• Myth: Tulips are forever. Plant them once, and you’ll have blooms for life.
If only this were so! While some species of tulips will come back faithfully for several years, most don’t, and are more often planted as annuals. There’s a reason Stan Hywet and Kingwood Center dig up their tulip bulbs each spring; for reliable tulip displays, new bulbs must be planted each fall.
• Myth: Add pebbles to the bottom of containers to improve drainage.
If you’ve done this for years, you won’t want to believe me, but adding pebbles does not improve drainage. Pebbles actually take up soil space and hold more moisture in the soil. Use containers with drain holes, and use a piece of screen or a clay shard to keep soil from escaping through the hole. Choose a good potting mix instead of bagged topsoil for the most healthful root environment.
Denise Ellsworth directs the honeybee and native pollinator education program for the Ohio State University. If you have questions about caring for your garden, contact her at 330-263-3700 or click on the Ask Denise link on her blog at www.osugarden.com.
