Garden Lore -Demystifying 10 Garden MythsMay 19, 2013 01:14PM ● By Lisa Drake
When I first developed a sincere interest in gardening back in the late 1980’s, answers to my many, many questions inevitably required a trip – either to the library or for a visit with an elder member of the gardening community to absorb some local wisdom. In today's website saturated world, my early information searches may seem like a hardship; having tea with a neighbor was indeed a greater time investment than a quick Google search. But like most investments, those that are carefully considered are usually more valuable in the end.
Gardening misinformation is viral on the Internet today and what seems like good advice can be shared and spread so quickly that it is nearly impossible to discern truths from half-truths, pure propaganda and outright falsehoods. Many of the sources of these modern garden myths are websites with links to the professional “home and landscape” industry - so what is a well-meaning gardener to do? If you don't have time to dig deeper, here are some common tales from the cyber-world that might have you perplexed.
1. "Drought tolerant plants don’t need to be watered." Validity: False. "Drought tolerant" is a popular marketing label for plants in our area, but all living things need water – especially the first year they are planted. Even a well-established xeriscape needs a good soaking once every six weeks during our hottest and driest summer months. When planting drought tolerant varieties, be sure to mulch them well and then wean them off of weekly watering while they establish fully developed root systems in your garden.
2. "Sand will fix clay soil." Validity: False. Adding sand to clay soil will turn it into brick. To break up clay soil, chop into the surface and add copious amounts of organic matter such as bark and compost.
3. "Newspaper makes an effective weed barrier." Validity: True, but you must know how to apply it properly in your beds. Pictures of single sheets of newspapers under a fine layer of mulch have been floating around social media sights for some time now, and make this method look like a too-good-to-be-true way to control weeds. Unfortunately, a single layer of newspaper will decompose much too fast to provide any smothering effect on underlying weeds. To effectively block weeds from growing, newspapers need to be soaked in a large bin of water until saturated, placed in thick layers (think the whole Sunday Sports section) over weeds or grass that have been cropped to soil level, overlap each other by at least two inches on all sides, and then covered with a heavy enough mulch to hold them in place as they dry.
4. "Vinegar is an effective herbicide." Validity: True, especially if applied in concentrated doses and with a surfactant. Plain old grocery store white vinegar will kill the foliage of undesirable plants almost instantly on a hot day, but sturdy weeds that tend to re-grow from roots will require several applications. For better results, try concentrated vinegar that is formulated as an herbicide, and add ¼ cup dishwashing liquid per gallon and a tablespoon of orange oil for extra weed-killing punch. Use caution – be sure not to allow any spray mist to land on your desired plants and crops as it will burn them.
5. "Epsom salt is a good organic fertilizer." Validity: Half-Truth. Epsom salt is nothing more than magnesium sulfate, and some plants are very magnesium hungry. This important mineral is often left out of traditional, non-organic commercial fertilizers, and when a plant is magnesium deficient it can look pale and in need of nutrients. To use Epsom salt alone on your garden as a fertilizer substitute will mean your plants are not receiving much needed doses of macronutrients such as nitrogen, phosphorus and potassium, as well as other micronutrients like iron and manganese. Furthermore, when more than 1 teaspoon of Epsom salt is mixed per gallon of water, it can 'burn' plants by causing roots to lose moisture through osmosis. Epsom salt is a great addition to an organic fertilizer regimen. Just be sure to add it in tiny amounts to something that will give a broad range of nutrients to your plants, like diluted fish emulsion and compost tea.
6. "Egg shells are an effective fertilizer for tomato plants." Validity: Half-Truth. Egg shells are high in calcium, and calcium is an important micronutrient that prevents blossom-end rot disease in tomato crops. As with Epsom salts, egg shells are not a substitute for a complete organic fertilizer program for tomatoes or any other plant; they must be used in conjunction with products that contain a balance of nutrients. Furthermore, egg shells break down quite slowly. To be effective as a soil additive, be sure you dry your shells completely and then powder them in a blender or food processor. Scratch the powder into the soil around the root zone of your tomatoes and supplement with an additional calcium source (such as gypsum) if signs of blossom-end rot appear.
7. "Goldenrod makes you sneeze." Validity: False. Goldenrod is insect pollinated, not wind pollinated like ragweed, grasses and many trees. Because the showy, yellow flowers of goldenrod bloom at the same time as ragweed (which has imperceptible flowers), it is falsely accused as being an allergy culprit. Goldenrod is actually a wonderful addition to the garden and feeds many beneficial insect species. Unless you are unusually susceptible to multiple allergens of all types, goldenrod will not bother your nose.
8. "Citrus peel halves make dandy decomposable pots for starting seeds." Validity: False. This widely shared image of a lemon half with a seedling planted in its rind is cute, but if you let your children use citrus peels as decomposable pots they are likely to wind up disappointed. Citrus peels decompose very slowly over several seasons even in the heat of a compost pile. The peel is thick - and roots are not likely to be able to penetrate through it once planted – thus causing your seedling to be stunted or to die once planted. You don't need to sacrifice the cuteness of this project altogether, simply treat your peel pot like any other pot and remove the seedling from it before planting.
9. "Green peppers with four lobes are female and full of seeds. Avoid them." Validity: Absolutely False! Like most plants, peppers have perfect flowers that contain both male and female parts. The only difference between a three lobed pepper and a four lobed pepper is one lobe. Very few plants have male and female flowers on separate plants (mulberry is one exception), so worries about the gender of your vegetables are unfounded.
10. "Cinnamon is an effective rooting hormone for plant cuttings." Validity: False, with a twist. Cinnamon does not contain any plant rooting hormone (indole butyric acid) and will not force cuttings to produce roots. However, because it can be effective at preventing fungal infections, a dash of cinnamon over your soil can assist with propagation success.
Much of what we see on the Internet – particularly on social media sites – is passed from friend to friend so quickly that mistakes can't be corrected before the damage is done. If you see a garden idea that seems too good to be true, be sure to check with a trusted source before experimenting on your own landscape. Research posted on university websites, agricultural extension agencies' sites and published garden authors' pages are generally trustworthy. And never underestimate the power of a cup of tea with a long-time-gardening neighbor.
BONUS: Here's a list of my favorite gardening resources:Howard Garrett - The Dirt Doctor
Local guidelines for organic gardening and soil health
Texas A & M - AgriLife website
Identifying disease and nutrient deficiency, Texas recommended varieties, planting dates, links
Planting dates for Texas:
Local source for organic gardening supplies
Baker Creek Heirloom Seeds
Rare, heirloom, affordable seed source:
Plant Physiology Online
Scroll down for images of plant nutrient deficiencies, specifically tomato plants