Gardening: Time to bust some gardening myths

The internet is full of quick and cheap homemade fixes for gardening problems. In a few cases, the homemade recipes might work, but often they don’t and come with side effects that are worse than the original problem.

Homemade weed killers. Homemade weed killer recipes that contain cinnamon, clove, peppermint, orange or vegetable oil or household vinegar can kill some weeds, but they won’t kill them down to the roots and the weeds come back quickly.

Household vinegar at 5% acetic acid is too weak to break through the leaf cuticles of many weeds so it may have little effect on them. Horticultural vinegar, which is 20% acetic acid, will kill weed tops as well as burn your hands, face and anything else on which it is spilled. It is more dangerous than some commercial weed killers. Pulling the weeds instead of spraying them will have better long-term results.

Using ground-up vegetables as fertilizer won’t feed your plants. The thought here is that spraying the juice from ground-up vegetables onto your vegetable crops will feed your plants. It isn’t a bad idea, but in doing so you remove the solids strained from the spray that could make good compost and create a lot of work for yourself. Vegetable scraps are best added to a working compost pile that will both feed the plants and improve the soil in the long run.

Using ice cubes to water plants is a bad idea. Ice cubes are often used to water orchids and other houseplants. This seems like a simple solution to get water to the plant roots slowly. Most houseplants, however, are from topical regions that are warm, and the icy cold water can damage them. Research from the University of North Carolina Botanical Garden found that orchids watered with ice cubes slowly declined in vigor over a six-month period. It’s better to use lukewarm water to water your houseplants.

Adding rocks to large pots does not improve drainage. Adding rocks, pottery shards, pine cones or foam pellets raises the water table in the pot enough to drown the plants. When water hits the boundary between the soil and the fill material, the surface tension of the water doesn’t allow the water to drain away. Instead, the water ponds above the material boundary and backs up into the roots, drowning them and killing the plants. It’s better to fill the pot completely with a good potting mix.

Homemade bug spray recipes aren’t always effective. There are hundreds of recipes out there that use garlic, hot pepper, tobacco and essential oils that supposedly will kill bugs on your plants. While these ingredients are found in commercial organic insecticides, their impact can be spotty and short-lived. They are more likely to damage the plants than kill the intended bug. Commercial sprays that contain these ingredients have been carefully formulated and assessed for effectiveness. Commercial sprays often contain fixative agents that hold the spray on the leaf longer.