Many of us want to become better gardeners and we seek advice from different sources in order to achieve this goal, but some advice out there related to gardening is helpful and some advice is myth.
Here are a few myths that many of us gardeners may have already tried or are thinking about trying.
The first myth is using large amounts of coffee grounds in the garden.
Coffee grounds can be used in compost and mixed in with our soil; but using too much is of no benefit and can actually be harmful to our plants.
You can add coffee grounds to your compost, but it should only represent around 10-20%. Anything more is too much.
A bucket of coffee grounds is shown prior to being used on plants. Used under license: https://creativecommons.org/licenses/by-sa/3.0/ (Shanegenziuk/Wikimedia Commons)
You can use coffee grounds as mulch for starting seeds in spring. Some seeds will do well in coffee ground mulch; but some won’t. If you want to use coffee grounds as mulch in the garden, only use about a ½ inch and then top with regular mulch. Anything more than ½ inch, will cause your soil to repel water so your plants won’t get the moisture they need to grow strong and produce blooms or fruit.
No benefit has been found in using coffee grounds as an amendment for your trees, especially when planting new trees.
Another myth is that coffee grounds lower the pH in soil, allowing growth of blueberries or those beautiful blue hydrangeas. Note that pH is a measure of how acidic the soil is. These types of plants need more acidic soil to be grown successfully. Coffee grounds do not lower the pH in our soil and, in some cases, might raise the pH.
Another myth is using vinegar as an effective weed control.
Regular table vinegar we can buy in the grocery store is not very effective in controlling weeds. Numerous studies have shown that you will need many repeated applications to see any changes in younger weeds that are beginning in late winter and early spring.
Field Bindweed, aka Convolvulus arvensis, is shown. Used under Creative Commons license: https://creativecommons.org/licenses/by-sa/4.0/deed.en (Josep Gesti/WikimediaCommons)
Even with repeated applications, table vinegar has little effect on the roots of perennial weeds such as dandelions or bindweed. This is because table vinegar is around 5% acetic acid and it just isn’t strong enough.
Table vinegar has also been found to have no effect on large weeds that are growing later in the summer.
There is a product called Horticulture Vinegar, which is around 10-20% acetic. This product will kill weeds effectively; however, it is extremely caustic and capable of burning skin and eyes, and inhaling the fumes can cause serious internal burns, as well. This product is also expensive, so it is probably best to use other herbicide products to control weeds.
Mosquito Repelling Plants
Citronella is a plant that is sold by some companies that make the claim that simply having the plant in your garden will repel mosquitoes.
Citronella planted in your garden will have no effect on repelling mosquitoes.
A mosquito is pictured biting a person.
The only way Citronella or any other plant that makes the claim to repel mosquitoes can work is if the plant is crushed to release the volatile oils and applied like a lotion or spray to your skin. In this way, Citronella does work to repel mosquitoes, just like DEET products we have available to us.
The best thing you can do to help repel mosquitoes in your yard is to eliminate any standing water. Water in bird baths should be refreshed often to avoid attracting mosquitoes; water in fountains that is constantly moving is not an issue as moving water does not support the egg laying of mosquitoes.
A Bug Zapper is shown. Used under license: https://creativecommons.org/licenses/by-sa/3.0/ (ZooFari/Wikimedia Commons)
The final myth is that insect zappers control insects around your yard.
It is true that insect zappers will kill many insects; however, more than 99% of these insects are beneficial and will help you in the yard.
Insect zappers also are not effective in killing mosquitoes, especially the females that lay eggs.
Current studies show that around 4 million insect zappers are sold each year and over 71 billion insects that are beneficial and don’t bite humans or animals are killed each year as a result.
Lacewings are beneficial insect for gardens. These are small, green insects with large transparent lacey wings. They feed on aphids and other soft-bodied insects. (Leslie Weinsheim/Courtesy photo)
Studies have also found that out of every 14,000 insects killed by an insect zapper, only 31 were biting insects. The best thing we can do to control insects is to recognize that over 97% are beneficial, helping to reduce the population of nuisance insects and our need for insecticides.