Miracle Gro fertilisers can be great assets to your lawn and garden when used correctly. They come in organic and chemical varieties as well as specialised formulations designed for use on specific plants including roses, flowers and tomatoes. While some believe using more fertiliser than recommended can help plants grow, this is a myth. But when used correctly, once every seven to 14 days, Miracle Gro can help your plants grow bigger flowers and vegetables and larger, thicker leaves.
According to the Alabama Cooperative Extension, "homeowners and gardeners are among the worst abusers of chemical fertilisers." Many gardeners believe that because using fertilisers can improve plant growth and appearance, the more you use the better. Many gardeners use products such as Miracle Gro more frequently or in larger volumes than recommended. The truth is, using too much of any kind of fertiliser, including Miracle Gro, can harm plants and the environment.
If you overuse Miracle Gro, you risk burning the leaves of your plants. The salts in fertilisers cause plants to lose moisture, which can lead to yellowed, spotted or wilted leaves. Overusing fertilisers in hot, dry weather can cause worse leaf burn. Any damage to the leaves makes plants more susceptible to pests and diseases.
If Miracle Gro is used more than recommended by the label, it causes plants to grow much more quickly than usual. While this may be exciting at first, fast growing limbs tend to break more easily. Breakage can encourage insect infestation, which can then affect other plants. When used according to the label, growth is not so extreme as to cause breakage.
While Miracle Gro is designed to prevent nutrient deficiencies in plants, because many Miracle Gro products contain high levels of nitrogen, they can exacerbate certain deficiencies such as iron. Because Miracle Gro causes leaves to grow more quickly when iron is already limited, it can cause extreme stress on plants trying to grow new leaves without proper nutrients.
Increased Pest Populations
Plants that are high in nitrogen are very attractive to insects as they provide extra nutrients that insects need to thrive. According to the North Carolina State University Extension, tomato plants that were heavily fertilised experienced increased thrip infestations and thus increased viruses brought by the bugs. Whiteflies, another garden pest, have also been shown to breed with higher frequency on plants with high nitrogen levels.
Use Miracle Gro and other fertilisers according to the label's directions. If you are worried about your plants' nutrition, amending your soil with organic matter such as compost or manure can help nourish your plants for longer periods of time and improve the soil.
- Alabama Cooperative Extension: Don't Overuse Fertilizer in Your Garden or on Your Lawn
- North Carolina State University Extension; Fertilizer Overuse; 2009
- University of Arizona; Using Fertlizers Wisely; Jeff Schalau
- Scotts: Scotts Miracle Gro Organic Choice Spray
- Scotts: Scotts Miracle Gro Shake 'n Feed
- University of Maryland: Fertilizer Pesticide Burn