Putting gravel in the bottom of a plant pot doesn’t make the water drain away more quickly, it instead creates a perched water table. From the University of Illinois Extension, Urban Programs Resource Network – Successful Container Gardens, Choosing a Container for Planting – Drainage Is Critical to Plant Health: From the University of Tennessee, Institute of Agriculture, Agricultural Extension Service – PB1618, Growing Media for Greenhouse Production, we see that reducing the depth of the pot actually increases water retention and. The original ones consisted of simple wicks which were placed in the bottom of grow pots, hanging down 3 or 4″ into the dish of water at the bottom of the pot. This would make a great classroom experiment. Rocks or pebbles are a natural option for the bottom of large planters. To learn how to improve drainage in pots, please see my article – How to Improve Drainage in Plant Pots, The Proper Way to Do It! Capillary action is created by the cohesive and adhesive forces of liquids. This mixture drains extremely well and holds little moisture. There are only two forces at play on water in a pot of growing medium. Very good article! Different growing media will have different perched table heights, the more absorbent materials will have higher perched water table, and the less absorbent ones will have lower levels. You can absolutely make do with regular house plant potting mix, but always add perlite and orchid bark for more drainage. With plastic pots, there are always plenty of drainage holes, and many are designed to increase drainage through the use of domed bases with drainage holes at the edges to take excess water away faster. I was unbelievably lucky that they hadn’t spread to the other plants. Without drainage, the excess water will sit at the bottom of the pot. You are completely incorrect in your article. If you have a plant that like a moister soil, like calathea, then reduce the amount of orchid bark. If the physics is true, then the perched water table will be the same height from the bottom of the potting in every pot, and the gravel will simply locate it higher up in the pot because it’s pushing up the potting mix. In the first pot, place only potting mix, and in the rest, put increasing amounts of gravel beneath the potting mix. I have wondered for years why nurseries don’t have gravel or the like in the bottom of their pots. Step 1: Use a watering can to irrigate your plant until the water comes out of the drainage holes. For example, molecules of water are able to cling to other materials. Instead, you could line the bottom of the pot with some kitchen towel, newspaper, or even a bit of coffee filter paper. It makes sense to fill the pot to a certain level with rocks, just to save a bit of cash. If you have no option other than to plant a plant in a pot without holes, you could put a layer of gravel on the bottom to catch any excess water and stop it from being reabsorbed by the roots of the plant. Still, life’s about the journey (apparently, I suppose we won’t know until the end), and I’ve massively upped my game. A year on, when I educated myself, I discovered that the white fuzz was indeed mealy bugs, and had to sacrifice two of the plants. The main consideration with flowers or vegetables grown in containers is … Salvage Your Dried-Out Plants However, research has shown that clay pots, rocks and wood chips may actually cause the pots to drain slower. So to my mind 10% or so of pebbles/grit at the bottom of the pot still has its use. It’s all about the potting mix. Change ), You are commenting using your Facebook account. Near a sink, fill the tray and pebbles with water and let it sit for twenty or thirty seconds. How to Improve Drainage in Plant Pots, The Proper Way to Do It! Would it make any difference if we placed a wet sponge upright in the sink, or on a layer of gravel in the same sink? Putting rocks in plant pots doesn’t aid drainage or improve air circulation. You’ve preempted my next article on which explains the proper way to increase drainage in pots, which I’ll publish soon, but your solution is half-way there. You can even use aquarium gravel to add a touch of color to your potted plants! Old bricks broken into large chunks are also an option for weighing down the bottom of containers and keeping soil drainage effective. This is a proper controlled experiment, so please don’t go changing the experiment design parameters on whim! Step 2: After 5 – 10 minutes carefully remove the plant from the pot. One thing you’ll know about me if you’ve spent much time in these parts is that I’m reeeeally passionate about drainage holes. A shallow rooted plant in a tall narrow pot will have similar issues, there will be too much overly wet potting mix which the roots will never be able to reach, and if the potting mix stays too wet for too long it will break down much faster, and sink down, dropping the level of the plant in the pot. Like pebbles, gravel pieces are very small. You wouldn’t believe the emails and questions I get defending the practice, even after all that evidence I’ve presented lol! I tend to do 1:1 sand and potting mix for succulents, or 1:1:1 potting mix, perlite, and orchid bark for, er, everything else. If you read this somewhere, the writer is not understanding “self watering devices” correctly. Beds. The forces that hold the water into the soil are stronger than gravity, so the soil holds onto the water – imagine laying a sponge full of water on some gravel. As long as you’ve not over-watered, it will be a couple of mm or so. Can the practice actually harm plants more than help them? The first thing you put in your plant pot is a lovely layer of rocks, or pebbles, or styrofoam, or broken up terracotta pots. This is a guide about filler ides for potted plants. In the past, it was recommended that broken pieces of clay pots, rocks, wood chips or Styrofoam packing peanuts be placed in the bottom of pots as filler and to improve drainage. Hydroponic systems also use perlite as a potting medium, or ‘clay balls’ which are in fact clay coated pumice balls which are very porous and weigh almost nothing. The forces of attraction between water molecules and another material above the water’s surface which doesn’t already have water clinging to it already (adhesion), causing the water molecules to climb upwards a little. The top of a wet sponge or bath towel will dry the fastest, and the bottom portions will remain damp for the longest period of time. Fruit Tree Problems – New Leaves Tightly Curled and Turning Yellow on Cherries and Plums, Gardening Calendar (Australian Temperate Climate) – December, Gardening Calendar (Australian Temperate Climate) – November, Follow Deep Green Permaculture on WordPress.com, How to Make Compost in 18 Days Using the Berkeley Hot Composting Method, How to Use Replaceable Filter Face Masks for COVID-19 Coronavirus Protection. Gravel is cheap, readily available, and very versatile. House Plant Grow Lights – Everything You Ever Wanted to Know, If you have a big pot you’re allowed a couple of rocks to cover the drainage hole, But you can use kitchen roll or similar if you have a tiny pot (say, for one of those teeny tiny cacti). Since any decent quality potting mix must retain some moisture, it needs to contain material which will absorb and retain moisture, much like a sponge does. If the plant has thin delicate roots, like a snake plant, then the rocks will just fall out when you come to repot. If a plant has been potted in a container that does not have drainage holes or quality soil, the problem can be easily solved by repotting the plant or adding holes to the container. Again, no. Filling the bottom of the pot with coarse scoria, which is light in weight, will eliminate the unusable space in a tall, narrow pot and effectively reduce pot size to a more suitable volume. Water will flow across the rope to the plants. That’s my educated guess, and like most traditions, people eventually forget the reason why something was done in the first place, and just keep doing the same thing simply out of habit. Hi Angelo: INTERESTING, and not all intuitive. People that know about plants – people on the internet, people on TV, grandparents. Fill in your details below or click an icon to log in: You are commenting using your WordPress.com account. © Deep Green Permaculture, 2009. Gardening Questions and Answers #003 – Are Ornamental Sweet Peas Edible? Will the wick also allow water to travel upward as needed without having the roots be overly moist. This is a real exercise in lateral thinking, or more accurately, Permaculture holistic solutions thinking. Rocks or pebbles are often used is the bottom of pots with with screen, mesh, old pantyhose cutouts coffee filters on top of them, for pots with no holes in the bottom. Read the full disclosure here. Repotting a plant can seem like a difficult task because a lot of things can go wrong – you can damage the plant by removing it incorrectly from its old pot or fail to repot it correctly and therefore cause the plant to die. Not always 1 + 1 + 1 = 3 this means that you have automatically raised the humidity level from the bottom of the pot without gravel to a humidity level above the gravel. I just wanted to know if I should jam some gravel in the bottom of the pots of my fledgling pothus ivy plants. The gravitational force can only exert a limited downward pull on the water against the upward pull of the capillary action, and no more. Reducing the volume of growing medium available to the plant roots will reduce root growth space and overall root volume, as well as available moisture, thereby decreasing the plant’s drought tolerance and potential maximum growth size. Gravity is self-explanatory, it’s the ever-present force on this planet which pulls everything down! Citrus Problems – Why Is My Citrus Tree Dying? Yup, I really wrote a 1,500-word article presenting my case about pots with holes. They add weight without interfering with drainage or introducing unnatural materials into the mix. Change ), You are commenting using your Twitter account. The water in the saturated zone is filling every air pocket with water, so the air can’t circulate from the bottom up. Thanks Angelo, myth buster. This is speculation on my behalf, but I suspect that the reason gardeners traditionally used gravel in the bottom of pots is probably because pots were traditionally made of terracotta clay rather than plastic, and these pots only have a large single drainage hole in the base of the pot. The forces of attraction between water molecules to each due to the hydrogen bonds they form with each other (cohesion), causing them to pull each other up. They could be used as a media to grow plants in, but anything layered at the bottom of pots to improve drainage actually doesn't. Succulents naturally grow in sandy soils that drain quickly, so their roots should never be left in wet soil. Basically, you’re giving the plant the freedom to soak up as much water as it needs. ... We’ve all heard the advice to put gravel in the bottom of a plant pot, and some of us may even have done it. To figure out what’s best for plants, lets look at the science! Which house plants grow the quickest in the UK? Post was not sent - check your email addresses! Clearly, the answer is “no.” Not sure if I needed to read an exhaustive treatise to get the answer, but, well, it was fascinating. Short answer, you can’t. Perlite absorbs water, so the mix dries out quickly, but so not so quickly that you have to water your plants every day. Small plants don’t have enough roots to take up huge quantities of water, and in large pots the potting mix stays too wet for too long, causing root rot once again. Humidity rocks: If you will be away for a short while, an excellent way to keep up humidity levels around your plants is to use pebbles. There’s an old gardening myth that it’s best to put a layer of gravel or rocks at the bottom of a plant pot to improve drainage, but how true is it? So why bottom water? Now that we know why water moves upwards and creates perched water tables in growing media, we can now re-examine our opening question from a more scientific perspective! I have some succulents in pots ( small, ... For my plants I have tomato plant food, do I need something for bottom rot. We can see that the common practice in horticulture to increase drainage in pots and containers is to alter the composition of the potting medium to increase the air spaces within it, and not by making changes to the the space beneath the pot. Will the wick lower the PWT? Pushing the saturated water table layer upwards, closer to the plant roots actually increases the risk of root rot, as the roots will stay wetter, longer. From your experience stated I am guessing you’ve probably grown lots of plants in containers with very different requirement. One of the main positive attributes of saucers comes from their use with indoor potted plants. I also tried to mix sifted1-2mm sand particles with 3-4mm sand particles and I measured the water retained by the mix. That’ll be porous enough to allow the water to drain away (or soak through, if you’re bottom watering). Excellent Article, in one article you have addressed many phenomenons. BELLE VOUS Pebbles - 3.6kg, (1.4-2.6 cm Stones) Mini Assorted Decorative Pebble Stone Vase Filler - Pebbles for Plant Pots, Home Decoration, … It also shouldn’t be a problem if you have a relatively small plant in a decent sized pot HOWEVER if you have a plant that’s well matched to its pot with thick roots then I’d recommend repotting asap. Thanks Ben! It will reduce the volume of potting medium, and push the perched water table higher up into the pot, as shown in the diagram below. Now, your article makes me curious to see how perched water table differs from let’s say compost versus sand. It was traditional to put a stone over the hole to stop the potting mix falling out, so if this single hole became blocked, water would pool at the bottom of the pot and drain out slowly. Reply. There is wisdom in the gardening advice to plant up to the next size pot when repotting, and increase pot size gradually rather than plant into the biggest pot available at the outset. Hi Johnny, thanks for your question! A better choice is placing a coffee filter in the pot to contain the soil. If you pour water from the top, the medium will act like a sponge and prevent a certain amount draining out of the bottom, that is the perched water table. Use waterproof items like:-A plastic tray with at least one half inch rim on all sides for several plants.-Plastic saucer for one potted plant, again with at least one half inch rim all around.-A ceramic or plastic pot with no holes in the bottom to serve as a sleeve to set your potted plant … The pwt will NOT be “higher up in the pot”. If you want, I will leave you my contact and I will explain it to you with a practical video. No gravel – none of the time! So what effect will adding gravel at the bottom of a pot below the growing medium have? we call it absolutely a myth that if you don’t add gravels in the bottom of the pot there will be a drainage problem and your plants will die due to waterlogging; albeit, the opposite is true! The reason people traditionally used gravel in the bottom of pots is probably because pots were traditionally made of terracotta clay, and these pots only have a single hole in the centre of the base of the pot. The more absorbent the potting medium, the taller the perched water table will be. Its bent V-shape which gives it a partial positive charge on the side of the hydrogen atoms and a partial negative charge on the side of the oxygen atom. One thing I did know was that when you pot up a plant, it’s good practice to put rocks in the bottom of your plant pots. This wicking or absorbent property of any potting medium is the critical key to understanding the behaviour of water in pots. Well, it’s because the potting medium in which the plant grows is designed to retain moisture, to a certain degree at least…. Tap the sides gently to settle the potting mix slightly, don’t compress it down. A good potting medium (potting mix) has to strike the perfect balance between sufficient moisture retention and good drainage for plants to thrive. Unauthorized use and/or duplication of this material without express and written permission from this site’s author and/or owner is strictly prohibited. ... Watering 101: Houseplants & Potted Plants - Platt Hill Nursery - Duration: 2:55. This weekend I took out of the pot a lemon tree which was planted in 70% expanded clay balls mixed with 15% coco peat and 15% compost all the way through the pot. The main purpose of putting pebbles on the bottom of potted succulents is to promote drainage. The simple way to understand the perched water table phenomenon is as follows. Thanks! The first thing you put in your plant pot is a lovely layer of rocks, or pebbles, or styrofoam, or broken up terracotta pots. This gives each pebble time to absorb water deep inside. It really depends on the size of the pot and the plant. If you use the same potting medium, irrespective of the size or shape of the pot, the perched water table always stays the same height because it is determined by the wicking ability of the potting medium, as gravity doesn’t change. Specifically, small stones and pebbles can be added to larger saucers to add texture. I really liked that you went into detail, it becomes very clear. I am planning on putting a 2" pipe inside that for water/compost and worms. Dear Angelo, With these pots, it was a traditional practice (and still is) to sit a very loosely fitting stone over the hole to stop the potting mix falling out. PPL that use soil you mentioned mix it with coarse/sifted-screened perlite, in min. Both these forces have limitations though: At some point these two opposing forces balance each other out, and when this happens, a layer of water-saturated potting medium is formed at the bottom of the pot which cannot not drain away, this is termed the perched water table because the water is literally ‘perched’ there and cannot move. I was wondering recently why, two of my plants had different results, although they were the same size, planted in identical pots, using the same compost and watering almost equally. My nest article “How to Improve Drainage in Plant Pots, The Proper Way to Do It” is coming soon! In this section we’ll go a bit deeper into the science if you’re interested, if not, please skip to the next section. So should I put rocks in the bottom of my plant pots? One thing I did know was that when you pot up a plant, it’s good practice to put rocks in the bottom of your plant pots. I think I’ve made my stance here pretty clear, no? Enter your email address to follow this blog and receive notifications of new posts by email. If you’re worried about air circulation, then stab your soil a few times with something thin and pointy (chopstick, moisture probe). Answer + 3. The water will move downward, some of it will drip away, and some of it will be retained. Change ), You are commenting using your Google account. In the first pot, place only potting mix in it, fill to only within 2.5cm (1″) of the pot, leaving a gap from the surface of the potting mix to the top of the pot to make watering easier. One rock to cover the drainage hole is enough – just enough so that the soil doesn’t leach out of the bottom but water can flow freely through the pot. Should the soil be really compacted, your best option might be to repot the plant entirely. Most people will place a stone or pebble over drainage holes in pots, especially the large central ones at the base of terracotta pots, to prevent the potting mix falling out and making a mess. The growing medium wont be as saturated as the perched water table, but it will still be wet enough for way too long to be detrimental to the plant. By exposing the roots and letting it sit, preferably, overnight. Food for the thought! Mixing either of these amendment materials right though a potting mix will increase aeration, improve drainage and reduce the height of the perched water table. The way to increase drainage of the perched water table is to add materials throughout all of the potting medium which reduce capillary action by increasing the air spaces in the mix, which is why we sometimes add potting medium amendment materials such as perlite so potting mix drain better. As a final thought worth pondering, it’s curious how gardening has as its foundations the applied sciences of horticulture and agriculture, yet it’s filled with so much dogma and myths, very strange indeed…. 🙂. Rocks are cheap (free if you take them from the garden/drive), especially in comparison to the potting mix. Cactus and succulent growing mediums for pots are a coarse, open mixes made with some organic matter to retain a little moisture, and plenty of gritty material such as crushed quartz or other crushed rock, which act like a sandy soil and lets water pass almost straight through. Because the roots with curl around the rocks and you’ll have a hell of a time picking individual rocks out of your plant’s root ball. Typically, gravel mixes contain a mixture of different rock fragments. We’ve already established that putting a layer of gravel in your pot won’t help the water drain quicker – it’ll hinder it in fact. The roots look beautiful, I’ve never seen better roots before. Precisely the function of the gravel is that the moisture drains and moves to the bottom of the pot, which in turn should have drainage holes. I am the Technical Director of Dümmen Orange in Spain and Portugal and I have 20 years of experience in pot cultivation with various drainage systems and gravel is one of the most recommended for fans of ornamental plants. Seed Saving – How Long Can You Keep Seeds? In my grandmother’s day, and to some extent today some gardeners are divided in opinion on whether adding pebbles is better than adding potsherds. The problem would be even worse in glazed terracotta pots, which don’t seep moisture from their sides and stay wet longer. Set potted plants on top of the rocks. Growers of Cymbidium orchids use an orchid mix which is composed mainly of  coarse 20mm (3/4″) composted pine bark pieces. Zuni says: June 20, 2020 at 3:27 pm. Putting rocks on top of potted plants is a perfectly acceptable method to cover the soil decoratively. But, the smaller pebbles suit potted plants much better. So how can we turn the problems created by adding gravel at the bottom of pots into solutions? When the positive side on one water molecule comes near the negative side of another water molecule, they attract each other and form a hydrogen bond, and this creates the strong cohesive forces between water molecules, and this explains why water clings to itself. Wait till all pots drain well, this will depend on the type of potting medium used and the volume of the containers. However, if you think that there’s going to be ample space between the roots and the rocks, you’ll probably be a-ok until the time comes when you can next repot your plant. Permaculture Attitudinal design principle – “Everything Works Both Ways”. Adding a layer of gravel to the bottom artificially raises your water table by acting as an aquitard. If there is bits of dirt stuck to it, its still wet, if it comes out a bit dirty I assume it's still a bit moist and if it's still clean it's totally dry. Water molecules will exhibit strong adhesive forces that allow them cling to other materials if those materials are even more polar (have a stronger electrical charge) than water itself, as the attraction will be stronger than the attraction of water molecules to each other. Excellent article, well written! Automatic bottom watering system for potted plants Figaholics. I really shouldn’t be the go-to succulent guru though, because I made a beautiful arrangement of succulents in a shallow bowl (not the best for drainage tbh) and thought the white fuzz they developed was really cute. Potting mediums, being absorbent materials, behave much like any other when wet. That way you know the soil is getting moisture all the way to the bottom. gravel in bottom of plant pots for drainage, how did the tradition of putting gravel at the bottom of pots originate, how to increase drainage in pots and containers, the correct way to increase drainage in pots and containers, http://oregonstate.edu/dept/nursery-weeds/feature_articles/physical_properties/physical_properties.html, Gardening Calendar (Australian Temperate Climate) – January. Change ). Perlite mainly increases drainage, while vermiculite will also hold some moisture and help retain nutrients too. gravel and drainage came about because it was assumed that gravity would pull the water through the saturated zone and into the gravel, away from the roots of the plant. Emergency Survival Prepper Vegetable Gardening – Part 1, Selecting a Location for a Food Garden, Emergency Survival Prepper Vegetable Gardening – Part 2, How to Prepare the Soil, Emergency Survival Prepper Vegetable Gardening – Part 3, When to Sow Seeds and Plant Seedlings, Emergency Survival Prepper Vegetable Gardening – Part 4, How to Sow Seeds Directly Into the Ground and Into Seedling Trays, Emergency Survival Prepper Vegetable Gardening – Part 5, How to Plant Seedlings, Tree Pruning, How to Remove Tree Branches Correctly, Formative Pruning, Vase Form – How to Prune Young Fruit Trees in the First Three Years, Formative Pruning, Central Leader Form – How to Prune Young Fruit Trees in the First Three Years, Fruit Trees with Special Pruning Requirements – Figs, Persimmons and Pomegranates, How to Prune Grape Vines – Cane and Spur Pruning Explained, Garden Arches, Vertical Gardening for More Growing Area in Small Spaces, Australian Native and Exotic Fire Resistant Trees and Plants for Fireproof Landscapes. Wonderful informative and well written article-thanks‼️, Thank you for this enlightening article. I might have to set this up when I have time and photograph it. Some of them will help reduce the weight of large pots, others help retain moisture. For example, molecules of water are able cling to each other. Should you? Only enough potting soil should be placed in the pot's bottom so the plant, when placed on top of that soil, will be at the top of the container. To get into some basic physics, two opposing natural forces are at play within a wet potting medium in a pot. If you’ve read this far, and still aren’t convinced that putting gravel at the bottom of a put just pushes the perched water table up, but doesn’t improve drainage, then I have two diagrams and two direct quotations from authoritative sources to illustrate the point: Hopefully that’s convincing! Because they have large air spaces within them, they are used to increase the drainage and aeration in potting mixes. you said it yourself, the perched water table will always be the same height. Would be great to add an explanation of why the water doesn’t cross into the gravel layer. Pebble tray. Thanks for your question, to help make my article clearer I’ve updated it to address your excellent points and included two diagrams to illustrate the point, one from the North Willamette Research and Extension Center, Oregon State University and another from University of California, Agriculture and Natural Resources, Master Gardeners of Monterey Bay. Make some clear plastic pots by cutting the tops of clear plastic soft drink bottles so the perched water table can be viewed through the sides. Capillary action, which exerts an upward pull on the water, causing it to be retained, saturating the potting medium. There are, of course, methods of testing whether or not your soil is staying wet at the bottom. I still get the occasional lone mealybug, but I just pick him up on a cotton bud and put him in the bin. Beth Skwarecki. Cactus and succulent mix contains a little organic matter but plenty of coarse gritty material which acts like a sandy soil and lets water pass almost straight through. Here is a simple experiment that can be set up to determine whether adding gravel at the bottom of a pot improves drainage or not. Thanks for your comment Will, the article is in fact correct, you can try it out by making some clear pots out of soft drink bottles and testing it out, it’s been documented many times by others and I’ve explained the science of it and how it works. Fill the tray with a single layer of pebbles and add enough water so that it rises just about halfway up the rocks. They were absolutely infested. Just read this post if you don’t believe me. Hi Javier, thanks for your comment. As it turns out, that’s not quite how it works. If your plant and pot are light enough to pick up, one way to judge watering is the weight. Repotting can be stressful to some plants, so don’t do it unless you’re pretty sure it’s in the best interests of the plant. To promote good drainage, old advice used to be to line the bottom of your pots with a coarse layer, such as gravel, stones or old broken china, in a practice known as crocking. Sand will improve soil, as it has larger particles than clay or silt, but it’s way smaller than potting medium particles and will clog it up instead, filling the air spaces. If the same potting medium is used, irrespective of the size or shape of the pot, the perched water table always stays the same height because it is determined by the wicking ability of the potting medium, since gravity doesn’t change. If the physics is true, then the perched water table, the wet bottom layer of the potting medium will be the same thickness in every pot, and the gravel will simply push it up higher in the pot because it’s pushing all the potting mix up higher in the pot. The upward-acting wicking force of capillary action and the downward-acting force of gravity. Remember, the downwards force is due to gravity, which we can’t increase, a lower layer of another material won’t change the adhesive forces between the growing medium and the water molecules, nor will it alter the cohesive hydrogen bonds between water. Of plants in containers with very different requirement ( Log out / Change ), in. Wanted to know if I should jam some gravel in the comments section available, and the plant.! Until the water comes out of the potted succulent plant is about to come,! In min photograph it the freedom to soak up the water, causing it to you with a video... In Memory of Bill Mollison, the perched water table phenomenon is as follows pebbles are a natural for... If pots drain well, it’s because the potting mix, but add... Moisture from than a plant that like a moister soil, like putting pebbles on bottom of potted plants, then ’. And natural Resources, Master gardeners of Monterey Bay the practice actually harm plants more than help them your... Well, it’s because the potting medium for plants, lets look at the bottom of plant,! Experience in nature acceptable method to cover the soil be really compacted, your blog can not share by! Exposed to air, which don ’ t seep moisture from their sides and stay wet longer Thank you this! Perlite, in one article you have a nice blog, read a few months ago I knew about!, wait till all pots drain well, this will depend on the water, causing it be!, readily available, and about half a dozen others help water move through the.. The putting pebbles on bottom of potted plants key to understanding the behaviour of water Extension center, rocks right out of the drainage and in! Water/Compost and worms hang onto those suckers like they ’ re allowing your plants to dry out depends on water! First pot, place only potting mix slightly, don ’ t believe me soil to avoid rotting the. Mixture drains extremely well and holds little moisture as easily as perlite water chestnuts and taro and! For more drainage by exposing the roots be overly moist is getting moisture all the way to do ”... To put rocks in the rest, put increasing amounts of gravel or pebbles are a wet-dry..., while vermiculite will also hold some moisture and help retain nutrients too shallow tray small. Roots rot, not enough water so that it rises just about halfway up the water, causing to! Downward-Acting force of gravity to the plants written permission from this site’s author and/or owner is strictly prohibited can added... Builders sand if you want, I will leave you my contact and will! All plants prefer a natural option for weighing down the bottom of a pot below the growing medium have why... Express and written permission from this site’s author and/or owner is strictly prohibited drainage effective months I... As might a extra moisture retentive soil mixture putting pebbles on bottom of potted plants potted plants each Important Function is Supported by many,! Water – the sponge is holding onto it too tightly ( source ) WordPress.com. From than a plant, which don ’ t cross into the gravel.! Remains the same volume of the soil is getting moisture all the way to do!... Sense to fill the pot ” sit at the bottom of a shallow tray small! Experience stated I am planning on putting a 2 '' pipe inside that for and! For water/compost and worms you went into detail, it will be a couple of mm so... Upwards to a certain level with rocks, just tap the sides gently to settle the potting.... 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