Even the tiniest of areas may benefit from the aroma and vibrancy that herb gardens provide, not to mention the additional convenience of always having access to freshly harvested spices. A good number of these plants may be grown either outside or indoors, provided that they are given the appropriate circumstances, which may include the perfect amount of light and temperature. There is a possibility that the herb plants may produce yellow leaves if some of the circumstances are not optimal. Finding and treating a problem is made easier when problems are addressed and fixed one at a time.
Lack of Fertilizer
Even while herbs often need little in the way of maintenance, their growth must nonetheless be supplemented with fertiliser. The appearance of yellow leaves on a herb plant may be an indication that it is deficient in nutrients, especially nitrogen. When you would ordinarily water the plant once a week, you should instead begin feeding the herb a liquid plant food that is balanced, such as 14-14-14. To avoid fertiliser burn, which may also result in the leaves becoming yellow, the fertiliser should be diluted to half its original intensity.
Too Much or Too Little Water
The majority of herbs have a strong preference for damp soil that is also porous. If the soil in your herb garden is too compact, the herbs that you plant outside may demand that you add a soil supplement such as sand to the soil. If you are going to be growing your plants inside, you should choose a sterile potting soil that has drainage-enhancing ingredients like peat moss. If you want the roots to remain wet, you should water them at least once a week inside and much more often outside, particularly when the weather is really hot.
When the leaves of a herb turn yellow, it’s a common sign that the plant is dehydrated and shedding its leaves to preserve energy. However, yellowing leaves may also suggest that the plant’s roots are getting too much water and are starting to rot. After watering the soil, wait a few days and then press your finger down into it to a depth of approximately an inch. If the soil is still damp or soggy after the next watering, reduce the amount of water you use or space out the waterings further. If the soil is totally parched, you need to water it more often and give it a larger amount of water each time.
Temperature and Light
Herbs have a wide range of specific temperature and light requirements; but, in general, they need at least five hours of direct sunlight each day outside, and maybe even more if they have access to indirect light from a window. The majority of them need daytime temperatures in the upper 60s or low 70s Fahrenheit, however it’s possible that they may tolerate brief exposure to higher temps. If the leaves that are becoming yellow are located at the bottom of a bushy herb plant, it is probable that their colour change is occurring due to the fact that the leaves are being shadowed by leaves that are higher up on the plant.
It won’t affect the plant if you remove the yellow leaves, but if you want the herb to be less bushy when you harvest it for cooking, you should attempt to trim it in a strategic way. When the temperatures outside are really high, consider shifting any outside plants that you have to more shady regions or watering them more often, even daily, until the heat wave passes.
Other Possible Issues
The leaves may also become yellow for a variety of different reasons, including the fact that the plant will soon need a larger container. If they get rootbound, which is when the roots begin to grow in circles around the inside of the pots, you should transplant them into pots that are about 2 inches bigger in diameter. There is also the possibility that the pH of the soil is not ideal for the development of the plant. Sage (Salvia officinalis), for example, which may be grown outside in plant hardiness zones 6 through 9 according to the United States Department of Agriculture and inside all throughout the nation, requires a soil pH of 5.5 to 6.5. [Citation needed] Some illnesses, such as fusarium wilt, may also induce yellowing of the leaves, but the yellowing usually begins as circular spots on the leaves or occurs in conjunction with wilting and other symptoms, such as stunted development. Although cutting sick leaves is often all that is required to contain a disease, in many instances it is better to dispose of the plant together with the soil in a plastic bag. This will help to prevent the illness from spreading to other types of herbs.
Some diseases, such as fusarium wilt, cause leaf yellowing as well, although the yellowing typically starts as circles on the leaves or accompanies wilting and other symptoms such as stunted growth. In many cases of disease, disposing of the plant and soil in a plastic bag is the best option to prevent the spread of the disease to other herbs, although removing infected leaves is sometimes sufficient.