Houseplant Care – Page 12 – Gardener Report

Has your once glorious string of hearts plant started to die back, and you have no idea why? Fear not! The same has happened to me. My mistake? I assumed the string of hearts was a succulent, similar to the string of pearls plant. I gave it the same watering regime and sunlight as my string of pearls plant, and the heart-shaped leaves started to turn brown and die back! Since then, I have gone on a mission to research how to diagnose and revive a string of hearts. I have experienced all of the problems (or helped others solve them firsthand) I talk about in this article, and I'll share with you all the tips and tricks I've learned in a step-by-step guide... In a Hurry? Here's my 2 sentence breakdown... A string of heart plants usually die because of overwatering and damp soil around the roots, which causes the leaves to turn yellow and the roots to rot. String of hearts is sensitive to cold and can die back in temperatures consistently lower than 59°F (15°C). I should also highlight that a string of hearts can also turn brown due to sunburn, and the lower leaves drop off as a reaction to low light levels. Keep reading for why string of hearts plant (Ceropegia woodii) is dying and the best practices for how to prevent it from dying and revive the plant... Yellow Leaves on your String of Hearts? How to Identify Overwatering and Save Your Plant Symptoms. String of hearts plant leaves turning yellow with soft stems. Causes. Watering too frequently, the soil draining too slowly, pots without drainage. So, for us to save our plants, we need to undertsand how they grow in the wild...String of hearts are native to Africa and are growing wild in Zimbabwe and South Africa. In their native habitat, they grow in rocky or sandy soils and live in areas with occasional rainfall and low humidity. Therefore, they are reasonably drought-tolerant compared to most houseplants. If the string of hearts plant is in consistently damp soil then this causes stress which causes the leaves to turn yellow and the plant can suffer from root rot which may turn stems and leaves black. We need to think about the fact too much moisture around the roots is not only caused by overwatering by also: Your potting soil holds too much moisture and stays damp for too long (or it's too compacted and doesn't drain properly), Your pot doesn't have drainage holes in the base. You might be using a saucer or tray underneath the pot, which is full of water. What I've learned from caring for my own string of hearts is that it thrives when the soil is soaked, and then you allow the top inch of the soil to dry between each bout of moisture rather than consistent moisture. So for us to revive our dying string of hearts we need to replicate the dry conditions of the plants native habitat with infrequent watering, special fast draining soil and to plant it in a pot with drainage holes that allows water to escape. I must emphasize that it is important not to use fertilizer at this time as feeding a plant that is potentially dying is often detrimental to the health of the plant, which is a common mistake I see beginners make when they try to revive a plant! It should be noted that string of hearts is very susceptible to dying in Winter due to overwatering because in Winter it is in a state of dormancy and not actively growing, therefore it requires less water. (For the best practices of care read my article How to care for string of hearts). How to Revive String of Hearts That is Overwatered (Step-by-Step) Scale back the watering. As we discussed, watering too frequently is the most common cause of a dying string of heart plants. Remember that our string of hearts is more drought-resistant than most houseplants, and it doesn't tolerate their roots being in potting soil that is damp. So what do we need to do? I replicate their natural watering conditions by giving my string of hearts a good soak once per week in the Spring and Summer and then water once every 2 or 3 weeks in the Fall and Winter whilst growth slows down. Watering frequency can also depend on humidity, with plants in more humid climates requiring less frequent watering. Replace your soil. String of hearts requires their potting soil to be particularly well draining. As I mentioned, ordinary potting mixes retain too much moisture and cause the leaves to turn yellow. So I use 50% special succulents and cacti potting mix for string of hearts which has the exact drainage characteristics to suit a drought-tolerant plant and add it to 50% regular houseplant potting soil (available from garden centers and on Amazon). This increases drainage and allows the roots and soil to dry out between bouts of watering. A gritty succulent soil mix is perfect for growing string of hearts plants. String of hearts plant requires a pot with drainage holes in the base. Without drainage holes, water pools around the roots and causes root rot. I always check every few months to see whether the drainage hole has become blocked in any way, such as with pot-bound roots or compacted soil. If so, re-pot the string of hearts in a slightly bigger pot. In my experience, string of hearts tolerates being pot-bound well and does not have a high requirement for fertilizer, so it can stay in the same pot for a long time as long as it is well-draining. Saucers and trays underneath the pot and decorative pots. Saucers underneath your potted plant prevent water from spilling in your home, but they also prevent excess water from escaping out of the pot, so the soil stays boggy. What I do is let water sit in the saucer underneath the pot for 30 minutes (I've found that this helps me achieve evenly moist soil after watering), but after 30 mins I discard any excess water. Decorative pots often do not have drainage holes in the base and can cause root rot and yellowing leaves. Are you unsure about watering? My best method for watering a string of hearts that I learned on a horticultural course is to feel the soil with your finger to 1-inch depth. If the soil is still damp, then delay watering for a few days. When the first inch of the soil is dry, give your string of hearts a good soak. I've found that this is the most effective way of meeting the string if hearts watering requirements without risking the leaves turning yellow due to overwatering! This way you can tailour the watering frequency to your string of hearts plant according to its environment, which (trust me) is a much better methoodology for watering! I do not recommend using a moisture meter or water gauge as, in my experience, they are not precise enough. I have used these when growing string of hearts, and the meter said that the soil had dried whilst it was still damp to the touch, which can, of course, cause root rot. Where I work in my garden center, I take care of many houseplants, and I've had the opportunity to experiment with many different potting mediums for String of Hearts. As I described, the 50:50 ratio mix of succulent and cacti soil and ordinary potting soil achieves the balance of moisture retention and drainage that we are looking for. However, I have found that a 50% mix of perlite or horticultural grit to 50% houseplant potting soil is also a great option, and I've grown a string of hearts very well using this mixture. I'd caution against using exclusively succulent and cacti soil because, as we know, our string of hearts shares some characteristics of succulents, but it isn't actually a succulent and, therefore, requires slightly different care. Once you have implemented these steps, the string of hearts can recover from water stress. However, If the leaves are turning progressively yellow or even black despite trying to revive the plant then the best option is to propagate string of hearts from cuttings. A string of heart plants is very easy to propagate. You can take cuttings from the healthy tissue of an otherwise diseased plant and successfully propagate them for many more plants at no extra cost. To see how it is to propagate string of hearts plants, watch this helpful YouTube video: https://youtu.be/bWw3UBYKpdQ?si=MesQ49Q2fNsodGhl Brown Leaves on Your String of Hearts? How to Diagnose the Problem Symptoms. Some leaves may have turned brown and scorched whilst other leaves appear healthy and green. Causes. Sunburn. Moving the String of Hearts plant from a relatively shaded area to an area of direct sun. Whilst our string of hearts is native to hot and dry climates, it is not necessarily suitable for full sun due to its sensitive leaves. (I found this out the hard way!) From my research, I discovered that string of hearts plants grow best in bright indirect light or some morning sun followed by afternoon shade. My problems occurred when I moved my string of hearts from a location of bright light to another location of direct sun. I was under the impression that, like its closely named houseplant counterpart, string or pearls, it would like some direct morning sun. This caused the leaves that were facing the sun to scorch brown, much to my dismay! It is easy to distinguish brown sun burnt string of hearts plants from other causes of stress as the leaves that are in the most direct sun are the ones affected whilst the leaves that are more shaded and on the other side of the pot can remain relatively green and healthy, so its an easy diagnoisis! Sun burnt leaves turn brown and look scorched. Unfortunately, when a leaf is scorched the individual leaves do not recover from a brown appearance, however, the rest of the plant can be okay and keep growing if the sunburn is fairly localized rather than the whole plant. How to Revive Your String of Hearts Plant With Brown Leaves So, as I'm sure you can imagine, the only way to revive sun burnt string of hearts plant is to move it to an area of indirect light to prevent further sunburn and trim off any damaged leaves, as I'm afraid these individual leaves cannot recover. What I did when this happened to me was to trim each string back to the base off the pot, with a sharp and sterile pair of pruners. If you trim back the stems with damaged leaves this should stimulate more growth and the plant can revive over the next few weeks. The perfect place for my string of hearts is now in a South facing room that has a sheer curtain up which diffuses the light, and my plant thrives. I also have one in my bathroom which has lots of bright light through frosted glass. (Read my article string of hearts leaves curling?) For severely sun-damaged string of hearts plants with lots of burnt leaves, I recommend attempting to propagate any of the healthier-looking stems to revive them. The String of Hearts Leaves Brown and Shriveled? Diagnosing Underwatering Symptoms. Leaves that have turned brown curled or shriveled. Causes. Under watering, watering too lightly, excess heat, and inappropriate soil mix. String of Hearts is noted for its tolerance to drought, but this does not mean it does not suffer from a lack of moisture in certain circumstances. A dehydrated string of hearts plant can be differentiated from a sun burnt plant because, with a lack of water the leaves should curl and look shriveled as well as turn brown whereas sun burnt plants tend to turn brown nut they do not curl or shriveled to the same extent. String of hearts suffering from drought stress also affects all the leaves, whereas sunburn only affects leaves that have had the most exposure to the sun. As I mentioned, I assumed that they had the same watering requirements as the much more drought-resistant string of pearls plant. I learned through first-hand experience that the distinction is that strong pearls like their potting soil dry out completely, whereas our string of hearts prefer just the first inch of the soil to dry between bouts of watering. I should also note that the string of hearts requires a good soak, usually around once per week, so that water emerges from the base of the pot. If you are watering less frequently than I was or too lightly, then drought stress can occur. A classic mistake people make with houseplants is watering too lightly. Watering too lightly may only moisten the top inch or so of the soil and not soak in to reach the roots where it is required. Another important factor we need to consider is potting soil. If the string of hearts is planted in soil that contains peat (as opposed to a mix of succulent and cacti soil and potting soil), then the soil can bake hard when it dries out completely. As I was leaving my string of pearls to dry out completely between each watering, the soil turned hydrophobic and so caused the water to run off the surface of the soil and down the side of the pot rather than reach the roots. I noticed after watering that the soil was immediately trickling out the base of the pot without infiltrating properly. I then picked up the pot to assess the weight, and it was suspiciously light, indicating the soil was not absorbing the water. Therefore, like me, you may give your plant a good soak, and water may trickle out the base, yet the water has not infiltrated the soil and reached the roots, causing drought stress. We also need to think about indoor heating. Excess heat from radiators or dry air currents from forced air or air conditioning can also increase transpiration (water loss) from the leaves and increase the rate at which the plant dries out and suffers from drought. (For all the best practices for watering, read my article on how to water string of hearts). How to Revive Your Brown String of Hearts Leaves? (Step-by-Step) Place your string of hearts in a basin of lukewarm water to help rehydrate the potting soil. Why lukewarm water? Because the string of hearts is from a warm climate, and cold water can shock the roots! I submerge the rootball under water for 30 minutes as this helps the hydrophobic soil absorb water properly, and the water can reach the roots where it is required. If you pick up the pot, you'll feel the difference in weight, I promise! This is how heavy the pot should feel after watering. Change the potting mix. If you think the problem is hydrophobic (water-repelling) soil, then re-pot your string of hearts in a mix of 50% succulent and cacti potting mix to 50% houseplant potting soil, as this mimics the soil characteristics of its native habitat and most importantly, it remains porous to allow water to effectively infiltrate the soil to reach the roots even when the soil has completely dried up. Wait until the first inch of soil feels dry, and then give your plant a generous soak. String of hearts usually do well with this balance of watering as it provides enough moisture for the plant yet allows the soil to be somewhat dry to avoid any effects from overwatering, and this emulates the moisture conditions of its native habitat with infrequent rainfall and good drainage. I must emphasize that when watering your string of hearts, give the plant a good soak rather than just a light watering. Do not interpret watering instructions to mean that it requires only a little bit of water. String of hearts requires a good soak so that water trickles out of the base of the pot. Light watering does not reach the roots, causing it to suffer from drought stress. Excess heat can increase water loss from the leaves and dry out your potted string of hearts quicker, which may cause drought stress in the Summer. In which case move it to a more shaded location and water the once a week with a good soak. Is Your String of Hearts Too Cold? (Keep your plant Above 50 Degrees F) Remember how we talked about recreating the conditions of the String of Hearts native environment? String of hearts are native to hot and dry climates in South Africa and Zimbabwe. They tend to cope very well with indoor temperatures, but they are not frost-hardy and, in my experience, are very cold-sensitive. If growth becomes limp, distorted, or blackened, then this could be damage suffered because of the frost. This has only happened to me once. I made the mistake of locating my string of hearts too near a window. Some of the heart shaped leaves were pressed up against the window pane, which was much colder then the ambient temperature of the room. Only the leaves that were in contact with the window became limp and started turning black. My solution was to simply cut back the blackened leaves. I used a sterile pair of pruners to prevent inadvertent damage to the plant. From my research, I discovered that string of hearts grows best in rooms that are 59°F (15°C) or warmer and can suffer due to cooler temperatures. Always locate your string of hearts in warm, bright rooms (and keep it away from cold windows like me), and the plant should revive. Is Your String of Hearts Turning Light Green and Growing Slowly? (It Needs more Sun!) As we've discussed our String of hearts plants are native to Africa and thrives in bright indirect light or morning sun followed by afternoon shade. Under these conditions, the plant grows best and remains healthy, with dark green leaves, often variegated with a range of whites and some subtle reds, depending on the variety. If your leaves are turning light green and the plant is slow-growing, this indicates that it is in too much shade. Light-deprived string of hearts tend to grow leggy with sparse leaves on the lower stems and some leaves drop off. It is important to note that not enough light is detrimental to the overall health of the plant and can cause it to die if it remains in too much shade. So what do we do? To revive it, move the pot to an area of bright indirect light. It is as simple as that. Do not move it to any direct sun as the contrast from shade to sun can cause it to burn. With the right balance of light, your string of hearts should revive. When I did this myself, I placed my string of hearts in a bright room with frosted glass, and I noticed the leaves started to turn a deeper green in 3 weeks and even started growing noticeably more. This was In Spring, so I would speculate these results would be slower at any other time of year. If the plant looks sparse, I would trim back excess growth, and it should recover. If the whole plant looks leggy, I would watch the YouTube video further up this article, take cuttings, and propagate your string of hearts for a more proportionate plant. Do you have any insights or any specific questions about string of hearts plants? Please leave a comment below, and I'll reply! I love to hear from you and talk about all things gardening! Key Takeaways: A dying string of hearts plant is often caused by overwatering or slow-draining soils, which causes too much moisture around the roots, resulting in yellow leaves and root rot. A string of hearts plant leaves turn brown from sunburn and can fall off if there is too much shade. The leaves of a string of hearts turn brown and shrivel due to underwatering and high temperatures. However, the string of hearts can die back in cold temperatures. To revive the string of hearts, water them once per week and plant them in a well-draining succulent and cacti potting mix. If there is significant sunburn or yellowing of leaves, propagate any healthy growth to revive the plant.