Signs of Too Much Nitrogen in Plants

Excessive Foliage

• When a plant receives too much nitrogen, there is an abundance of leafy growth. This misleads many gardeners in the beginning to think that their plant is thriving because of all the new growth, but wait a little longer. When no fruit or flowers form, and the leaves keep coming, it is a sign that too much nitrogen is being applied to the plant. If using a balanced 10-10-10 formula or similar, cut back to 5-10-5.

Weak Stems

• When it comes to plant stems, excessive nitrogen provides an example of when too much of a good thing turns bad. At healthy doses, nitrogen works to provide the plant the means to grow sturdy, supportive stems. Too much nitrogen makes the stems weak, which in return, makes the plant weak and susceptible to diseases and pests. Eventually the plant becomes too weak to stand up so it falls over and dies.

Sugar Content and Taste

• When plants absorb too much nitrogen, it affects the taste of the fruit or vegetable because the sugar and vitamin content in the plant is altered. The plant is unable to absorb the other necessary nutrients needed, which causes many crops to taste bitter.

Maintaining Healthy Nitrogen Levels

• Several reasons make it difficult to measure how much nitrogen the soil contains. Soil microbes control the daily supply of nutrients, and in extreme cold or hot conditions, or if the soil is waterlogged, microbes slow down, which slows down nitrogen release. This causes the gardener to think there is a nitrogen deficiency, but when soil microbes start moving again, the symptoms of excessive nitrogen appear. Adding ample amounts of organic matter, or compost, to the soil cuts back on the need to fertilize because it provides an abundant amount of nitrogen. The nitrogen contained in organic matter is released slower into the soil than commercial fertilizers that are made with readily available nutrients. Green manures also release organic nitrogen slowly and over a long period of time.