Hello, I am a Biologist and Chemical and Environmental Engineer. I also founded Moss Pure, the world's first and only company to use 100% LIVE moss as an aesthetically pleasing decor piece that doubles as a scientifically certified air filter and stress relief device. No watering, sunlight, or maintenance is needed. We work with architects, commercial construction companies, corporate offices, medical clinics, biotech, pharmaceutical, life sciences, luxury and high-end homes, etc. I answer your questions below. There is no scientific evidence that coffee grounds help plants in any way. So in general, I wouldn't recommend using it in your garden. There are also certain plants, such as Geraniums and certain herbs that are sensitive to caffeine and you should never add coffee grounds to the plants' soil. But here are certain and specific plants you should keep away from coffee grounds: Certain plants grow in higher pH soil (alkaline soil) of a pH from 7 to 12. Coffee grounds can slightly lower soil pH, making it more acidic (pH of 1 to 7). This can hinder growth of plants that survive in higher pH soil. Examples include lavender, lilacs, clematis, asparagus, thyme, rosemary. Coffee grounds can also increase the risk of fungal infection and root rot in plants. Because of this, plants that are more prone to fungal infection such as roses, azaleas, bell peppers, and squash should be kept away from coffee grounds. Coffee grounds should not be used with cacti and succulents either. Cacti and succulents like well draining soil and dry soil. Coffee grounds tend to keep soil wet and increase root rot. Because of this, coffee grounds should not be used. Coffee grounds should not be used on young plants or newly planted plants. The chemicals in coffee grounds can be too harsh on the plants and cause damage or even kill the plants. Please let me know if you have any questions. Jamie Mitri Founder and CEO Moss Pure https://www.mosspure.com
When you're looking into using coffee grounds in your garden, it's crucial to know that not all plants welcome them equally. For instance, plants that prefer more alkaline soils, like lavender and geranium, might not thrive if coffee grounds are added around them because of the grounds' acidic nature. Also, using fresh, uncomposted coffee grounds can inhibit the growth of some plants due to high caffeine levels which might affect surrounding vegetation. It's also worth mentioning that while coffee grounds can enrich the soil with nitrogen, they tend to mold quickly if not used correctly. This can cause issues with soil aeration and water retention. If you're considering using them in your garden, I'd recommend composting them first to reduce the potential negative effects and to make nutrients more accessible to your plants. Just remember, everything in moderation—overuse might lead to soil imbalances. As for me, I've been an active gardener for over 10 years, constantly experimenting with natural fertilizers and sustainable gardening practices. I've contributed to various online gardening blogs, sharing practical tips and personal insights into eco-friendly gardening.
Coffee grounds can be a nice addition to garden compost, but they aren't perfect for every plant. From what I've seen, some plants just don't do well with them. For example, stay away from using coffee grounds near acid-sensitive plants like lavender, rosemary, and asparagus. These types like their soil a bit more neutral or slightly alkaline, and coffee can make it too acidic. Also, if you have succulents or cacti, the moisture from the grounds could cause root rot. Vegetables like tomatoes can be picky too. I've noticed that tomato plants sometimes struggle where fresh grounds were mixed in directly. It might be because caffeine can mess with seed germination and growth for some plants. I had a few customers who tried using fresh grounds in their seed trays and didn't get any seeds to sprout. Another thing to watch out for is compaction. Coffee grounds are fine and dense, and if you pile them on too thick, they can form a crust that keeps water out instead of soaking it up. To get the best results, I always suggest composting them first or mixing them with existing compost rather than using them straight out of the bag. They can be a good boost for your garden, just not for every plant or in every way. About me: I'm Andrew Griffith, a horticulturist and the founder of Garden Furniture, my very own e-commerce store. After finishing university, I joined our family business, where we specialized in selling houseplants, gifts, homeware, and garden furniture to our local community in North Yorkshire.
Coffee grounds aren't for every plant. Avoid using them around lavender, rosemary, succulents, and cacti. These plants thrive in well-draining, slightly alkaline soil, while coffee grounds are acidic and can hold too much moisture, leading to root rot. Tomatoes also don't do well with coffee grounds, as the acidity and nitrogen can stunt their growth. Another issue is that wet coffee grounds can clump and block water and air from reaching the roots. They can also slow down seed germination due to the natural caffeine content, which acts as a growth inhibitor for some plants. My bio : I'm Hicham, an SEO expert who creates content in the kitchen and home improvement space. I focus on helping websites grow through well-optimized, practical content that's useful for real people, not just search engines.
Coffee grounds don't work well for every plant. Some prefer dry, well-drained, neutral soil. When coffee grounds make the soil too moist or acidic, growth slows, and roots suffer. Adding them without understanding the plant's needs often leads to weak results. Seedlings also react poorly to coffee grounds. The texture compacts easily and blocks airflow. Water can pool or run off instead of reaching the roots. Plants that need loose soil for early growth tend to stall in this kind of environment. Poor starts mean poor results later. Caffeine in the grounds adds another layer of risk. It lingers and can disrupt plant growth. Some types respond poorly and end up stunted. Overusing the grounds also disrupts the soil's natural balance. That throws off the bacteria and organisms that plants rely on. Stick with small amounts, and mix them with other compost materials. Focus on balance, not shortcuts. What feeds one plant might harm another.
I had to learn the hard way that though coffee grounds are great in moderation, not all plants love them. Using them around lavender, rosemary and succulents is a no-go, I avoid it at all costs because these plants thrive in drier, more alkaline soil. Coffee grounds can also retain too much moisture and raise acidity, which stresses their roots. I also keep coffee grounds away from seedlings and young plants as the fine texture of coffee grounds can compact and create a water-resistant layer, choking airflow and trapping moisture. Another issue is having too many grounds can attract fungal growth or even repel water instead of helping with drainage. I once added a thick layer around my thyme and ended up with soggy, yellowing stems, so never again. Now I either compost them first or mix very small amounts into well-aerated soil. Bio: I'm Mimi Nguyen: Vietnamese-American home gardener, sustainability advocate, and founder of a coffee e-commerce brand called Cafely. I've been gardening most of my adult life and have experimented with closed-loop practices like composting coffee waste. My practical experience helps bridge the gap between sustainability and what actually works in the garden.
I'm Valeria Nyman, chief product officer at Taim.io, where we teach people how to grow their own food, from seed to skillet. I've been a hands-in-the-soil gardener for over 25 years, and I've tried every weird idea the internet has to offer, including dumping way too many coffee grounds into the wrong beds. Where not to use coffee grounds in the garden, and why: The myth of coffee grounds as some kind of magic soil fairy dust really needs a reality check. They're NOT one-size-fits-all. For starters: never use them around seedlings. They can actually stunt growth. You can wipe out an entire tray of lettuce starts with an overenthusiastic espresso compost. Rookie move! Also, keep coffee grounds away from plants that hate acidic or dense soil. Think lavender, rosemary, sage: all those Mediterranean herbs that thrive in dry, loose, low-fuss soil. Coffee grounds are dense and can create a hydrophobic mat. Water beads up and runs off. The roots basically suffocate. As for plants that hate coffee grounds: Succulents are a big no. They like sandy, sharp-draining soil. Coffee grounds clog that right up. Also, tomatoes: when used in excess: they'll show yellowing leaves if the pH shifts too much. Blueberry bushes (which like acidity) also struggle when grounds were used too liberally. Other problems caused by coffee grounds in the garden: Coffee grounds can mess with the microbial balance. They contain allelopathic compounds, which means they can suppress some plant growth. That's not always bad, but it's unpredictable. They can also heat up if applied in thick layers. In short, I'd say that coffee grounds are not mulch. Use them in compost, small amounts, mixed in well. Feel free to trim or edit!