A drainage hole is a very minor feature when considering the overall size of a planter pot, but it’s long been the subject of debate. Some argue that all planters need drainage holes to help maintain the overall health of your plants. Others claim that it’s unnecessary to use planters with drainage holes in all scenarios. To alleviate that confusion, we’ve put together a comprehensive guide covering some top asked questions with answers on when and where we advise using planters with drainage holes, and alternative solutions if planters with drainage holes aren’t an option.
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Do plant pots need drainage holes?
Most plants require proper drainage to thrive. Though using a planter with drainage holes isn’t the only way to make sure your plant will survive, it is one of the easiest ways to make sure your plant doesn’t perish from over-watering.
Over-watering is typically how most plant owners inadvertently kill their plants. Any water that pools at the bottom of a planter can allow bacteria and fungus to form and cause root rot, which kills the plant.
Though every plant owner should know their individual plant’s care and watering needs, drainage holes in a planter allow any extra water to seep out.
Do outdoor planters need drainage holes?
There are very few scenarios where an outdoor planter should be used without drainage holes. Outdoor planters stay outside in the sun, rain, snow, and all the weather in between. When they fill up with water from inclement weather, the extra weight and volume can cause them to crack. In colder climates, that water freezes, expands, and breaks the planter.
Drainage holes—especially for outdoor planters—are key to ensuring your plants don’t get over-watered and that your planter stays intact through the elements.
Do indoor planters need drainage holes?
Thriving plants require proper light, soil, water, and drainage. However, most people don’t want excess water leaking onto their floors or furniture from a planter pot with drainage holes.
If you want indoor plants, it isn’t 100 percent necessary to have drainage holes in your indoor planters. However, if you want your plants to thrive, proper drainage is key. Here are a few methods to make sure your plants have proper moisture without traditional planter drainage holes.
“Cache potting,” or double potting, is a tried-and-true method to make sure your plant can maintain proper moisture levels without water leaking onto your furniture.
Find a plastic grow pot with drainage holes that are a bit smaller than your planter. Simply plant your foliage or flowers in the grow-pot, and place it into your chosen planter. The grow-pot will be hidden by the outer planter, and your plant will look like it’s directly planted. If you go this route, be sure to drain any excess water from the outer planter to help prevent root rot.
Shallow saucer dishes are made to be placed under planters to catch any excess water that may drain and prevent that moisture from ruining surfaces. Make sure to empty the saucer after watering to avoid standing water and root rot.
Beyond being a helpful solution, saucers can also add a decorative element to your planters. Fill them with pebbles or small stones for extra texture and interest.
Self-Watering and Sub-Irrigation Systems
Self-watering planters and sub-irrigation systems are another method you can use if you don’t want to use drainage holes in your planters. If you’re looking for a quick, simple set-up, there are self-watering planters available for purchase that already include self-watering and sub-irrigation systems.
These systems use a water reservoir and drainage system to give your plants optimal growing conditions. Plants then draw the water as they need it from the reservoir, which is separated from the plant’s root system. Some self-watering systems allow your plant to maintain adequate moisture for up to 12 weeks!
If you already have a planter you’d like to use, some self-watering and sub-irrigation systems can be purchased separately.
DIY Self-Watering Planters with Cross Risers and Capillary Wicks
Cross risers paired with cache potting is another way to make sure your plants have adequate drainage. Cross risers lift your grow pot and create a small water basin, which allows water to seep out and pool at the bottom of the outer planter. Because the cross risers are in place, your plant’s roots won’t sit in water, and as a result, won’t likely develop root rot.
When you pair cross risers with capillary wicks, you can make your own DIY self-watering planter. Simply stick a capillary wick through the bottom of your grow-pot, and let one end of the wick sit in the water basin. Water will be drawn into the soil through the wick as the plant needs moisture.
How to plant in pots without drainage holes
If double potting or using a saucer isn’t an option, you can directly plant in pots without drainage holes. However, if you choose this option, it is key to make sure you carefully monitor how much you water your plant.
To plant in a pot without drainage holes, simply place your plant in a planter filled with its preferred blend of potting soil. But in order for your plant to thrive, it’s essential to remember these next few tips.
The water you pour in isn't going out
Tilt your planter to the side if you overwatered
If you’ve added too much water, place your hand over the soil and slowly tilt your planter over to allow any excess moisture to drain. Any potting soil that is lost is easily replaced.
Do not place outdoors
If your planter doesn’t have a drainage hole, we don’t recommend placing it outside. Rain and other inclement weather will flood your plant and cause root rot from over-watering.
How to cover drainage holes in pots
Soil doesn’t commonly fall through planter drainage holes, but it is a common concern. Those worried about losing soil can use a few different household items that allow water to drain but keep the potting mix contained. Commonly used items include a fine mesh, piece of window screen, or even a coffee filter!
how to seal drainage holes in planter pots
Sealing up drainage holes allows you to modify a plant container into a more appropriate indoor planter. However, the most appropriate method to plug drainage holes will depend on the material make-up of your planter.
Some popular suggestions include purchasing a rubber stopper, using concrete, using a cork sealed with plumber’s putty, or filling it with silicone sealant. These are all viable methods to seal planter drainage holes.
Fiberglass planters are a bit of a different story. To seal a fiberglass planter, rough up the edges of the drainage hole with sandpaper. Then, fill it with Duraglas. From there, use a waterproofing seal and paint if necessary.
how to make drainage holes in plastic pots
Depending on the material your plastic planter is made of, it may not be possible to make drainage holes. Plastic that is stiff and brittle can easily crack. You may break the planter by trying to drill a drainage hole into the brittle plastic.
However, if you have a softer plastic planter, you may be able to drill a drainage hole that won’t crack or break your planter.
Spur-point drill bits, or dowel bits, are typically recommended for drilling holes in plastic. These types of drill bits are manufactured to make clean, neat holes in materials. The size of your planter will determine how big of a drill bit you’ll need, but a ½ inch spur-point drill bit is a good starting point.
Place your planter upright on a scrap piece of wood on a flat space. The scrap wood allows you to drill through the plastic, which helps avoid chipping and keeps your surfaces safe.
Mark where you’d like your drainage holes to be placed. Place your drill on the marks, and with a slow drill speed, let the drill cut into the planter material. A slow drill speed reduces the chance of the plastic melting due to heat from friction.
Let the drill press through the planter material and into the scrap wood below. Gently remove the drill, and you should have a neat new drainage hole in your plastic planter!
How to drill drainage holes in fiberglass planters
Fiberglass planters are durable, sturdy, and weather-resistant. Though it is possible to drill holes in your fiberglass planters, it’s often much more time-efficient to order fiberglass planters with drainage holes pre-drilled.
However, if you’d like to drill your own drainage holes in your fiberglass planters, here are the supplies you’ll need and the basic steps you’ll need to follow.
You’ll need face protection, a drill, a 1-inch or ½ inch spade drill bit, a pencil, a piece of scrap wood, and a wet/dry vacuum.
- Put the planter upright on the piece of scrap wood. We don’t recommend putting the planter upside down, as it can scratch the planter’s exterior.
- Use the pencil to mark on the planter interior where you’d like your drainage holes placed.
- Set the drill bit on the pencil marks and slowly pull the trigger to start drilling. Let the blade bite into the fiberglass until you’ve reached through to the other side of the planter.
- Use the vacuum to clear away any fiberglass dust.
How many drainage holes do you need?
The number of drainage holes needed will vary based on the overall size of the planter. However, a good rule of thumb is a minimum of two drainage holes. For a 36-inch planter, we recommend 3-4 drainage holes. For a 46-inch planter, 4-6 drainage holes should be sufficient. Be sure to consider the height and narrowness of the planter. For example, if you have a tall, thin planter, it might not make sense to drill 4-6 drainage holes.
Should You Use Planters with Drainage holes?
Regardless of whether you choose to use a plant pot with or without drainage holes, it’s crucial to be aware of your plant’s maintenance requirements. How often should you water it? What type of potting soil mix should be used? Will there be too much sun where you’re planning on placing it?
If you are dedicated to your plant’s care and simply make sure that it has proper drainage, you’ll be rewarded with lovely, thriving plants, whether your planter has drainage holes or not.