Why Your Houseplant's Leaves Are Turning Yellow and What to Do About It
When a previously lush, leafy green houseplant starts turning yellow, you might think it's a sign of impending botanical doom. But wait, don't panic! First, keep in mind that it’s natural for the older leaves on houseplants to slowly turn yellow and drop off. It's the plant's way of making room for new foliage. If you're seeing sudden yellowing of many leaves at once, however, that's definitely a distress signal. Take a closer look at exactly where the problem seems to be happening on your plant and then run down this list to match the symptoms with the solution.
Yellow Leaves on the Lower Part of Your Plant
There are three possible reasons and treatments. First, if roots are pushing through the bottom of the container it means the plant has run out of room and needs to be repotted into a bigger container with some extra potting mix. Second, the soil may be low in nitrogen, an important nutrient that plants need to grow properly. Lower leaves are usually the first to starting yellowing when a plant doesn't have enough of this element. Over time, your plants can use up all the nitrogen that your potting mix may come with, so repotting with fresh soil can help with this problem, too. Or, you can supplement with a fertilizer that is high in nitrogen. Third, try moving your plant to a brighter spot to see if more light helps green up its leaves.
Yellow Leaves at the Ends of Stems
If everything looks fine except for the growth on the tips of stems or branches, this could be a sign of low iron. Yep, just like us, plants need this nutrient to be healthy but only a teeny-tiny amount. Usually, a single dose of a houseplant fertilizer that contains iron (not all do, so be sure to check the label) will help clear up the problem.
Yellow Leaves Near the Main Stalk
If you have a branching houseplant and notice that the leaves closest to the central stem are the ones turning yellow, you may be dealing with low magnesium or zinc. Add a houseplant fertilizer that lists these nutrients on its label. Too little nitrogen could be the culprit for this symptom, too. Take a look at the label on your fertilizer of choice and you'll see three numbers separated by hyphens like 4-2-2. Those numbers show the ratio of nitrogen, phosphorus, and potassium in the formulation, which are the nutrients plants need the most. You want a fertilizer where the first number representing nitrogen is higher than the other two.
All the Leaves Turn Yellow
When your whole plant turns yellow, that could mean the soil is waterlogged so the roots can't get enough oxygen. If the soil feels soggy to the touch, don't water again until the top inch of soil dries out. And if the plant isn't too big for you to handle, pop it out of the pot and check the roots for rot. If they all look black and soft, the plant is likely a goner. But if you still see some firm, white roots, your plant may bounce back once it dries out a bit.
Yellow leaves all over your plant can also mean that it has pests like spider mites or a bacterial disease. If bugs are pestering your plant, put it in the shower and spray it hard with water, then treat it with some horticultural oil or insecticidal soap that your local garden center will have or you can get either one online. Repeat the spraying every week or so until the pests are gone. If you have a giant plant that is too heavy to move in and out of a shower, use cotton balls to wipe the leaves with water, then wipe again with horticultural oil or insecticidal soap.
Succulent Leaves Turning Yellow
The leaves of succulents are thick and fleshy because they store water. But there can be too much of a good thing. If these plants get watered too much, this causes edema, where the leaf cells swell and rupture. Corky, brown growths appear on the leaves, and eventually, the leaves turn yellow. A common problem in the winter, it is also easy to fix: Stop watering. Then begin watering again when the top inch of soil is dry. If you planted your succulents in conventional potting soil, you can baby them by repotting in a fast-draining cactus mix.