Truth About Garden Myths: Program Recap

There are so many myths about all things gardening that can have damaging effects on our plants and crops.

Thank you to Debbie LaGattuta from the Rutgers Master Gardeners of Monmouth County for illuminating dozens of myths associated with different aspects of gardening. With the prevalence of social media, it is easy for some myths to gain traction and cause more and more people to practice unhealthy and unsafe practices. Let’s take a look at the huge number of myths that are out there and learn how to tackle some of the most common problems we as gardeners face.

A Barrel Full of Myths

Watering

• Wilting plants need water – In fact, wilting is more of a sign that the plant is lacking internal moisture rather than the surrounding soil needing water. Some plants have developed a survival mechanism where they “wilt” or curl their leave during the heat of the day to conserve moisture and then relax when the temperature cools at night. Other reasons your plant might be wilting is that it’s root system is poorly developed and cannot access the water deeper in the soil or it has circling and kinked roots. Compacted soil, insects, or disease could also be the cause of wilting plants.
• You don’t have to water native plants – While native plants are adapted to survive in local conditions, including periods of little or no water, it does not mean that they never need water. Native plants require water at the initial planting and within the first year to encourage healthy root development. Once mature, some plants can survive without supplemental watering in the right conditions, which is species dependent.
• Drought tolerant means the same as drought resistant – Drought tolerate plants have adapted over time to tolerate periods of little or no water (less than average rainfall) while drought resistant plants are designed by nature to require very little water.
• Drought and heat resistant plants don’t need to be watered – While their moisture requirements are lower, all plants need water; these plants have just adapted to survive with less than ideal amounts of water.
• Water your lawn for 10 minutes a day to keep it lush and healthy – In fact, consistent, shallow watering forces the grass’ roots to remain at the surface, making them more vulnerable to drought. Also, the more water that remains on the blades of the grass, the more susceptible they are to disease. Established lawns benefit from infrequent deep watering of 1-2 inches per week.

Fertilizer

• A yearly 4-step fertilizer program is the best path to a healthy lawn – This approach actually generally applies too much fertilizer and needless herbicides and pesticides, causing thatch. The best approach is to first test your soil to determine what nutrients are lacking. Fertilizer only when necessary, once in the spring and once in early fall. All lawns need 3 pounds of nitrogen per 1,000 square feet per year; a mulching lawn mower provides 1 pound of nitrogen over the year, which reduces the amount of nitrogen fertilizer you need to apply.
• If a little fertilizer is good, twice as much is better – Too much fertilizer causes excess and toxic salt buildup in soil and results in reduced water uptake by roots; this can cause plants to become drought stressed, root injury, leaf burn, wilting, death, or lawn thatch. Follow the directions on the packaging – the label is the law!
• You can apply lawn fertilizer at any time of year – New Jersey actually has a fertilizer law that prohibits the use of fertilizers from November 15th through March 1st. Best practice suggests that fertilizer is best applied when turf needs food and actively growing in the spring and fall. Never fertilize your lawn int he summer or during drought conditions.
• You must apply lime to your lawn every year – Lime will lower the pH of your lawn, making it less acidic; if your soil is between 6.3 and 6.5 pH, your lawn is healthy and lime will have an adverse affects. Test your soil first to determine if lime is needed.
• It’s a good idea to use plant-specific fertilizers – There is no such thing as plant-specific fertilizer; it was invested by the marketing industry. Each manufacturer will recommend a different ratio of nitrogen-phosphorus-potassium (NPK); there is no consistency across the brands. The fertilizer you should use should be based on soil test results and the needs of the plants; fast-growing plants use more nutrients than slow growing plants.
• You must fertilize trees and shrubs yearly to keep them healthy – Do not routinely apply fertilizers for no reason; mature trees and shrubs growing in favorable conditions require little or no fertilizer. In fact, many home landscape trees acquire nutrients from turfgrass fertilizers. Soil testing should be used to determine what fertilizer is needed and if it is necessary, feed them in the fall.
• Brewing compost tea is worth your time and spraying it on plants works as a liquid fertilizer – Scientific studies are showing that compost tea often has no effect on plant health or disease control; some scientists even claim that it can boost populations of pathogens. While the tea can directly feed plant foliage, it cannot absorb all the nutrients it needs through its foliage. Never use compost tea on edible plants; you can apply it to the soil around ornamental plants.

Soil

• Sand loosens heavy, clay soil – The worst remedy for loosening any type of soil is adding sand. Clay particles will actually fill in the spaces between the sand particles, acting as a glue which can result in denser soil. To loosen heavy, clay soil, mix in organic matter like compost, humus, well-rotted manure, shredded leaves, or worm castings as this will break down to improve soil structure, increase fertility, and improve drainage.
• Peat moss loosens heavy, clay soil – Peat moss will actually increase the high moisture holding capacity of clay soil since it is light and porous, absorbing 10-20 times its weight in water.
• Peat moss increases soil fertility – Peat moss actually provides very little nutritional value and is harvested from non-renewable bogs, releasing CO₂ during harvesting. To improve soil fertility, use organic matter like compost, humus, well-rotted manure, shredded leaves, or worm castings.
• Adding gypsum loosens clay soil – Gypsum has no effect on soil fertility, structures, or pH and is used primarily to increase calcium levels on heavily farmed agricultural sites. Adding gypsum is usually a waste of money, natural resources, and can have negative impacts on plants, soil, and ecosystem health. Only add gypsum if your soil is lacking calcium or sulfur or for salt remediation.
• Brewed coffee grounds acidify soil – If you want to provide more acidity, use fresh coffee grounds rather than brewed ones; brewing removes most of the acidity from the grounds. Additionally, coffee grounds provide minute amounts of nutrients. A better use of brewed coffee grounds is to add them to the compost pile as an additional source of nitrogen.
• Banana peels add potassium to the soil, especially for roses – While bananas and their peels do contain potassium, the peels take a long time to decompose to release that potassium. The amount of nitrogen required to break down the peel means that less nitrogen is available for the plants. A better idea is to add the peels to your compost pile.

Vegetables

• Crushed eggshells and whole eggs add calcium to the soil and cure blossom end rot on tomato plants – While blossom end rot is a sign of calcium deficiency in fruits and eggshells do contain calcium, adding them to the soil will have no effect since the disease is not caused by a lack of calcium in the soil. The disease is actually a sign that there is a water uptake issue for your plants or the pH of your soil is too high or low.
• All suckers must be removed from tomato plants – Removing all suckers can cause sunburn or sunscald on the fruit. You can remove some suckers to open up the foliage canopy to allow better air circulation. Best practice is to leave a few suckers on the lower portion of the plant to grow more main stems for production, then prune suckers as needed to create air flow and produce larger fruit. Do not remove suckers on determinate tomatoes.
• Fertilize vegetable plants with a dose of epsom salt, especially peppers – Epsom salt is not actually a fertilizer as it only contains magnesium and sulfur. Only use epsom salt if your soil test indicates that you are deficient in magnesium and sulfur. If you are only deficient in sulfur, horticultural sulfur is a must better option.
• Sow peas on St. Patrick’s Day, March 17 – Soil is often too cold and wet to sow peas on that day, which can cause the seeds to rot. Don’t sow any type of seeds based on a specific date on the calendar. Wait for weather conditions to be ideal and soil temperature is warm enough.
• You can determine the gender of a bell peppers by counting their lobes – Peppers are not gender specific and the number of lobes does not indicate gender of the pepper.
• Eating carrots makes you see better – This was actually developed during World War 2 to explain the success of British bombers, a ploy to hide their invention of radar. While carrots do contain vitamin A, which is good for your eyes, fresh fruits and dark leafy green vegetables are better for your eye health. In fact, consuming too many carrots can turn your skin orange.
• Fresh vegetables are better for you than frozen vegetables – Fresh fruits and veggies usually deliver the most nutrients, but frozen produce is a healthy option. Vegetables grown for freezing are typically harvested at their peak ripeness and undergo a blanching process to minimize nutrient loss.
• Green potatoes are poisonous – Exposure to sunlight can cause potato skin cells to produce chlorophyll and turn green. You can eat potatoes if they are only slightly green, but they are not deadly. If a potato is very green or entirely green, just throw it out.

Composting

• Don’t add pine needles to your compost pile because they are too acidic – Pine needles are acidic, but become neutral once they start to decompose. Chopped pine needles are a great addition to a compost pile and are a good source of carbon. Compost piles need 4x more carbon than green nitrogen.
• You should add all of your grass clippings to your compost pile – Adding unlimited quantities of grass clippings creates a moisture and air barrier in the compost pile, which promotes growth of mold, bad odors, and slows down decomposition. Grass clippings provide nitrogen (green), but too much can disrupt the 4:1 carbon (brown)/nitrogen (green) ratio.
• Compost smells terrible – Properly made compost should smell like fresh soil. If you compost smells bad, you can fix it by adding the right ingredients (no meat or dairy products), use correct ratio of ingredients to achieve 4:1 carbon/nitrogen ration, dry it out if it’s too wet, aerate the pile, or move the pile to a sunnier location.

Planting Trees and Shrubs

• Dig planting holes twice as deep as the tree’s root ball – Digging the hole deeper than the heigh of the root ball can had an adverse effect on the root development of the tree and is the leading cause of mortality in newly planted trees and shrubs. Dig the hole 2-3 times as wide, but no deeper than the root ball; the shallow hold depth keeps the roots from settling too deep while the double width allows the roots to penetrate the surrounding soil.
• Amend newly-dug planting holes with compost and aged manure to give a nutritious kickstart – Roots often won’t grow beyond enriched planting hole soil, which will slow root establishment and sometimes kills young trees and shrubs. Backfill planting holes only with the original native soil; you can mix 25% composted organic matter with the backfill only if you have a very high clay content.
• Stake and tie newly planted trees to establish a strong root system – Research has shown that natural swaying stimulates faster development of anchoring roots and promotes a stabilizing taper to the trunk. Staking might be beneficial for large bare-root trees or top-heavy specimens that have outgrown their containers or for fast-growing evergreens that are vulnerable to winds. Remove all supports after one year to prevent serious trunk damage.

Mulch

• Planting mulch high and deep around a tree trunk prevents moisture loss and adds curb appeal – Mulch should not be more than 3 inches deep and should never touch a tree trunk. Large mulch mounds around trees will hold too much moisture against the bark, inviting diseases, insects, and rodents. It also blocks roots from getting sufficient oxygen and can cause root rot. It can also cause the tree to develop adventitious roots or girdling roots.
• The type of mulch material you use doesn’t matter – Chunky wood-based much is ideal, like arborist wood chips. If wood-based mulch is too finely textured, it can form a mat that inhibits water and air flow. Avoid using stones/rocks as these can heat up the underside of leaves, soil and roots as well as avoid plastic or rubber because it can add to landfills and does not break down.
• It is not safe to use woodchips from arborists because it could contain diseased wood – Research has proven that wood mulch created from diseased trees does not introduce diseases to the soil or plants where the mulch is spread. Also, wood chips from trees with growth-inhibiting properties when they were alive do not inhibit plant growth.
• Spread a new mulch layer every spring to top off the old mulch – Building up layers of mulch traps too much moisture and can impede water flow to roots. Use a rake to fluff up last year’s mulch. If that mulch is deteriorated, remove it and add fresh mulch.

Plant Care

• Braid or tie up daffodil foliage as soon as the blooms fade to keep the garden tidy – Knotting or braiding green bulb foliage restricts photosynthesis which transforms sunlight into stored energy; the bulbs need that energy to produce new foliage and flowers next season. Leave bulb foliage alone until it turns completely brown, then gently tug to remove.
• Sunlight shining through water droplets causes sunburn on leaves – Water droplets will not burn leaves, regardless of how strong the sun is.
• Watering plant foliage keeps plants looking fresh and hydrated – Wetting foliage does not do any good and actually encourages disease since fungi and bacteria use water to spread and infect plants. Plants absorb water through their roots, not their foliage; if you water by hose, try to water the base of the plant and avoid foliage.
• If a plant is under stress, feed it – When a plant is stress, its usually not from a lack of food. Fertilizing a plant that is not nutrient deficient can lead to additional stress. Typical culprits of plant stress are compacted soil, heat, salt spray, incorrect planting, improper placement, flooding, and transplant shock.
• Use ice cubes to water indoor, potted orchids – Ice is not natural for orchids as they thrive in warmer climates. While ice does provide the right amount of water, repeated use of ice cubes will damage the roots. When watering orchids, use room temperature water and submerge the pot until the potting medium is wet, letting it drip dry.
• Misting an orchid increase humidity around them – Misting exposes plant foliage to bacteria so you should never wet the leaves on any type of plant. Misting aerial roots is alright if the orchids are grown bare-root.
• Holiday poinsettias are poisonous to cats, dogs, children, and adults – At most, they are mildly toxic to cats and dogs and not poisonous or deadly; they rarely cause visits to the vet.
• Add sugar, aspirin, tea, pennies, rusty nails, bleach or lemon soda to a vase of cut flowers to extend their life – These ingredients are perpetuated by old wives’ tales and have no affect on the life of cut flowers. You can add floral preservatives to the water and that water should be changed every 2 days, along with a fresh stem cut.

Weeds

• Spraying household white vinegar kills weeds – Vinegar is non-selective and will harm any plant that comes in contact with. Vinegar will burn the top of the plant, but does not kill the roots. It can also acidify the soil and is harmful to amphibians, reptiles, insects and other small animals.
• Landscape fabric is a permanent solution for weed control – Landscape fabric can actually create a weeding nightmare, especially if topped with mulch. Weeds can germinate on the mulch or soil on top of the fabric and actually anchor their roots to the fabric, making it more difficult to get rid of them. The fabric can hinder the movement of organic matter and sterilize the soil. Unfortunately, there is no magic wand for weed control; you just have to be vigilant and pull them before they go to seed.
• Dandelions are invasive weeds that ruin soul health and serve no purpose in a garden – Dandelions can actually amend compacted soil by bringing nutrients to the surface and aerate that soul through its deep taproot. They also provide an early source of pollen for bees and other insects. Nutritionally, the dark leafy greens are rich in potassium and vitamins A, B, B12, and C.
• Goldenrod causes hay fever – In reality, it is actually ragweed that causes hay fever, which blooms at the same time as goldenrod.

Containers

• To improve drainage, add rocks, gravel, empty bottles, or pottery shards to the bottom of a container – Adding a layer of anything but potting mix will impede drainage. It will also raise the water table and can cause root rot.
• Outdoor containers don’t need drainage holes if you layer the bottom with stones and gravel – If a container does not have drainage holds, you will end up with a dead plant so drill or punch holes into the bottom of the container if necessary. Again, do not add anything other than potting mix to your containers.
• To save money, it is OK to fill containers with garden soil – Garden soil is only meant to grow plants in soil, not containers. It can contain insects, insect eggs, weed seeds and disease pathogens, not to mention that is often too dense and compacts easily. Only use potting mix to fill containers.
• You must replace container potting mix every year – If the plants in the containers were healthy during the growing season, you can reuse the potting mix next season. It is best to loosen the mix and then remove 1/3 to 1/2 of the old mix and add granular fertilizer and fresh potting mix to the old. However, you will eventually need to replace the entirety of the potting mix because it will break down over time.

Pests and Insects

• Homemade hot and spicy mixtures of household ingredients keeps pests aways from plants – Homemade brews are not science-based and can burn plants. Also, they might have an immediate effect on insects, but are not long lived. If other natural and safe pest control methods fail, purchase commercially-available insecticidal soaps or horticultural oils; synthetic chemicals are always a last resort.
• Organic pesticides are less toxic than synthetic ones – Many organic pesticides are less toxic, but that doesn’t mean they are safe or won’t cause environmental harm. Even if the active ingredient comes from a natural source, they are at a much higher concentration than would every be found in nature.
• If a pesticide is organic, you can use as much as you want – Overusing any type of pesticide can have detrimental effects on plants by burning the leaves or raising toxicity levels in the soil. Always follow the exact recommended dose – the label is the law!
• Spraying your yard for adult mosquitos and ticks does not harm other insects – Spraying hurts all insects, including those that are needed for a healthy garden. To help reduce the number of mosquitos, eliminate sources of stagnate water and create a habitat that attracts their predators, such as dragonflies, birds, spiders and bats.
• A Japanese beetle trap eliminates them on your plants – Those traps are baited with lures that can have the scent of flowers or beetle pheromones, which will actually attract more beetles to your yard that it catches.
• The best way to kill slugs is to sprinkle table salt on them – While salt will kill them, it can cause salt buildup in the soil and adversely affect your plants. You can go out at night to pick them up and drop them in soapy water or trap/lure them with beer traps, melon or citrus rinds.
• It is illegal to kill a praying mantis – It is not illegal to kill a praying mantis in New Jersey and there are no state or federal law protecting them.
• Spotted lanternflies are eating leaves and killing trees; a pesticide will get rid of them – They actually have piercing-suckering mouthparts and feed on plant sap. While they can be a nuisance, they have not been shown to significantly damage otherwise healthy ornamental plants. Squash egg cases, physically kill adults that are safely reachable, or leave for predators to feed on.

More Information

If you want to learn more about the myths debunked above, please check out the handout available at https://www.njstatelib.org/wp-content/uploads/2026/03/HandoutGardenMythsNJStateLibrary.pdf. You can also check out more from the Rutgers Master Gardeners at https://extension.rutgers.edu/master-gardeners.

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