Well-draining soil is recommended for most plants, but it can be elusive, especially if you live in an area that gets lots of rainfall.
So, how do you make your soil drain better? One way is to elevate your soil using hilling (soil mounds) or raised beds. You can also install a drainage system to divert water away from soggy areas. Another method is to loosen and aerate the soil by digging with a shovel or pitchfork. Adding worms to your garden will improve soil structure and drainage. There are also some soil amendments you can add to improve drainage.
We’ll get into more detail about how to use these methods later. First, let’s look at why you need well-draining soil, and how to tell if your soil drains well.
Why Do You Need Well-Draining Soil?
Well-draining soil is important to maintain the correct moisture levels for the plants in your garden.
If your soil does not drain well, your garden will stay wet for too long after watering or a heavy rain. This can lead to root rot, which eventually kills plants by preventing them from absorbing water.
Poorly draining soil can also lead to runoff, where you lose topsoil and nutrients when they are washed away by rain. For more information, check out my article on over watering your plants.
How to Tell if Your Soil Drains Well
If you know what type of soil you have, you can probably guess how well it drains.
Sandy soil drains well, but it does not hold nutrients well (as mentioned above, they may wash away due to runoff). Therefore, sandy soil will need more fertilizer to give your plants enough nutrition.
Clay soil drains poorly and holds lots of water, but it doesn’t hold much oxygen. You should add some sand, gypsum, or limestone to improve drainage of clay soil.
Loam soil is somewhere in between sandy and clay soil in terms of how well it drains water.
If you aren’t sure what type of soil you have, there is an easy way to tell how well it drains.
First, dig a hole 1 foot long by 1 foot wide by 1 foot deep. Then, fill the hole with water.
If the water drains quickly (in less than 10 minutes), then the soil is well-draining. If it takes more than an hour to drain, then the soil is slow-draining, and you will want to take some steps to improve drainage. If it is somewhere in between, you may need to improve drainage if your garden is in an area prone to flooding in spring or summer.
Methods to Improve Soil Drainage
If you’re reading this far, then you have determined that you have some drainage problems with your soil. As promised, here are five different methods to make you soil drain better.
Elevate Your Soil
When I use the word “elevate”, I don’t mean some mystical, woo-woo, law-of-attraction idea. Elevating your soil means raising it above the surrounding ground so that it won’t stay so wet after watering or rain.
One good method to elevate your soil only requires a shovel. The idea is to elevate your soil by creating hills (also known as mounds or berms), sometimes known as “hilling”. Then, you plant your seeds or seedlings on top of the hill, and provide water and fertilizer as usual.
The idea is that some water will soak into the mound to water your plants, and the rest will run down the sides of the hill. This will prevent the flooding and root rot mentioned earlier.
You can create one small hill per plant if you wish, or you can create a longer hill for several plants (or even for an entire row of plants!)
Another good way to elevate your soil and plants is with raised beds. This method requires a little more overhead, since you will have to buy the lumber, cut the wood, and put the pieces together.
The idea is that you build a rectangular wooden box, like a sandbox. However, instead of filling it with sand, you fill it with soil and then plant inside it.
There are tons of plans for raised beds online. One big benefit of raised beds is that you can make them any size you wish. If you want to elevate your plants even higher, you can use hilling within a raised bed.
If you use a liner in your raised bed, make sure to choose one that allows for proper drainage. For more information, check out my article on what to use for raised garden bed liners.
Install a Drainage System
Another way to improve soil drainage is to install a drainage system. The idea here is to get excess water to flow away from your garden by directing it with drains, pipes, and other channels, either above or below ground.
It may take a little digging, but a good first step is to create a slight incline away from your garden so that excess water flows away from it on all sides.
If you want to take more direct control of the water (such as from gutters or driveways), you can dig a channel. Then, either fill it with a pipe or with gravel (a traditional French drain).
Don’t do this without an incline, or the water will just sit inside the channel! Also, be courteous to your neighbors – discuss any drainage problems with them, and don’t send water into their yards.
Loosen and Aerate the Soil
This next method is something you might do to your garden anyway. If you dig up the soil with a pitchfork, shovel, or rototiller, it will loosen and aerate the soil.
When soil is compacted, it prevents water from flowing freely through the soil. By digging and moving the soil around, you prevent compaction, while also aerating the soil at the same time.
When you aerate your soil, you create more space between soil particles, so that water can move through more easily. You can learn more about rototilling if you check out my article on the cost of rototilling. You can also use spike or plug aerators to aerate your soil.
A spike aerator is what it sounds like: it uses spikes to put holes in the soil, which create an opportunity for air (and water) to permeate the soil. Unfortunately, this can compact the soil further, which is one thing you want to avoid to improve drainage.
A plug aerator uses a hollow spike to remove a small amount of soil from the ground. This method creates a hole by removing material, rather than compressing it.
For more information, check out this article from sfgate.com on spike and plug aerators.
One more note about loosening your soil: if you want to attract worms to your soil, use a pitchfork instead of a shovel or rototiller. Otherwise, you may injure or disturb any worms that are present.
Add Worms to Your Garden
Adding worms to your garden is a great way to improve soil quality in terms of structure and nutrition. Worms make soil less compact and aerate the soil at the same time. They also break down organic matter into a form that plants can use as nutrition.
You can try moving worms from another area of your yard, or from a friend or neighbor’s yard. You can also buy them at a bait shop, or online.
For more information, check out my article on how to get more worms in your garden.
Worms will not stay in your garden unless you give them a good reason to do so. One good way to keep worms around is to add plenty of organic material to your garden.
Another way is to put them in your compost pile or bin, where they will happily help to speed up the process of turning grass, leaves, and vegetable matter into compost for your garden.
Use Additives to Improve Soil Drainage
The fifth and final way to improve soil drainage is to use additives in your soil. There are a few different ones that will make your soil drain better, and perhaps help with nutrition at the same time.
This is the most common and well-known additive to improve soil drainage. Soil drains better when it contains more organic material, such as compost, manure, and mulch.
Making compost can take months, depending on how much help the pile has from bacteria and worms. However, it is a great way to recycle, including grass clippings, leaves from fall cleanup, and fruit or vegetable scraps from the kitchen.
You can even use wood ash, paper, cardboard, and many other materials to make your compost. If you are ambitious and have a large garden, you can ask friends, neighbors, or local landscapers if they have extra material you can use.
You can usually source manure from a friend who keeps chickens, or from a local outfit that boards horses. You can create your own leaf mulch by going over fallen leaves with your lawnmower in autumn.
Sand, Gypsum, or Limestone
Sand, gypsum, and limestone are good additives to improve drainage if you have clay soil. Make sure to use coarse sand, since fine sand can lead to soil becoming compact or hard.
Gypsum (calcium sulfate dehydrate) and lime (calcium carbonate) both help to improve drainage, in addition to providing extra calcium for your soil.
However, make sure to get a soil test before you add too much of these supplements to your garden. Excessive calcium can prevent plants from absorbing other important nutrients, such as magnesium.
You don’t need to visit a volcano to use this method to improve soil drainage. Perlite is a common volcanic rock, and it is generally available online or at garden centers.
Vermiculite is an alternative to perlite that holds more water, but allows less aeration.
Perlite and vermiculite both have air pockets, making them somewhat lightweight. They also absorb water well, meaning that they help to prevent soil from becoming too moist, while releasing water in times of drought (that is, when you forget to water!)
For more information, check out my article on perlite, vermiculite, and alternatives.
Hopefully, these five methods will help you to make your soil drain better and lead to healthier plants and an abundant harvest.
I hope you found the article helpful. If you have any questions or advice of your own about soil drainage, please leave a comment below.