Are drainage holes important in container gardening? That’s perhaps one of the questions that boggle your minds, especially if you’re starting out in this hobby. Whatever plants you’re growing, be mindful that proper drainage is crucial to their health. Otherwise, you’d be facing unhealthy and dying plants as standing water can cause irreparable damage to your crops. So, continue reading below as we’ll delve deeper into this topic and in the end help you achieve the best drainage for your container plants.
Why Proper Drainage is Important?
Plant roots, except for aquatic plants, don’t like sitting in water. Often, the surface may appear dry, but the soil at the bottom of the container can be drenched in water.
Too much water causes blockage in the air pockets of the soil. Thus, hindering the plant roots from taking in carbon dioxide and disposing of oxygen in the air and preventing them from carrying on the process of photosynthesis.
Such a scenario causes cell death and root rot, serious conditions that quickly kill the plant. Poor rot health symptoms include yellowing, wilting of the leaves that watering doesn’t solve, and eventual leaf drop. You can also tell that the roots are decaying if you see black or brown, mushy and slimy roots after removing the plant from its container.
Another reason why proper drainage is vital is to avoid salt from building up in the potting soil. Fertilizers and tap waters have salts, which are harmful to plants. It accumulates over time and creates an unhealthy environment that causes the browning of the leaves on the tips and edges. However, if there are adequate holes in the container, water drains freely and flushes out the salts out of the soil.
Typically, the number of holes should be around four to eight, no larger than ½ of an inch for small to medium planters, and an inch in diameter for larger pots. With the right number and size of holes, there’s better aeration and less soil to escape, while still keeping the soil well-drained.
Given all that, your container pots’ drainage plays an essential role in your plant’s life. By ensuring proper drainage, roots are stronger and in the best condition, resulting in fresher, healthier plants, veggies, herbs, or flowers in your container garden.
Tips on Improving Drainage in Your Container Garden
Now that you’re aware of the importance of good drainage, here are some valuable tips on improving it in your container garden:
1. Choose the Right Container Depth
While there is much concern over the type of soil and fertilizer, amount of sunlight, and watering needs, one thing most people overlook is getting the right container with drainage holes. Be wary that having the right pot is as important to growing your plants successfully.
First, you need to ensure that the pot has the right depth. A shallow pot means there is less aeration to your soil. If you get a pot that’s too short or small, sufficient air won’t let in and water isn’t flushed out. Even if you get the best growing mix, it will be negated as the environment below is unhealthy for your plants.
On the other hand, a deep container with the same soil promotes better permeability and aeration. Thus, also allowing better drainage.
2. Pick the Right Container Size
Another factor to consider is getting the right container. Smaller pots aren’t usually suitable for fast-growing vegetables like arugula, spinach, beets, bok choy, peas, and radishes as they restrain the growth of the plant roots, making the produce stunt. Moreover, small planters usually cause the soil to dry faster, needing you to water your plants more frequently than usual.
Meanwhile, placing them in a large pot isn’t also suitable. Water dries slowly in larger pots, and without proper drainage, your plants become susceptible to root rot.
To avoid such issues, pick a container that is 2-4 inches bigger in diameter for fast-growing plants, and 1-2 inches larger for slow-growing plants, based on the pot they’ve outgrown.
3. Select the Right Material
Today, pots are available in a variety of materials, from plastic to metal, glass, wood, and terracotta or ceramic. Though some of these pots are stylish and are pleasing to the eyes, be wary that the material also plays a huge role in getting proper drainage for your plants.
For instance, plastic containers are lightweight and cheap and come in a wide array of shapes and colors. If you want to have a colorful garden, they’re your best bet. Yet, plastic pots aren’t breathable, which means it’s difficult for excess to evaporate. They also trap all the heat, especially during the summer and when exposed to direct sunlight. Thus, cooking your plants.
Metal containers are inexpensive, too, and look stylish. However, like plastic, they aren’t breathable, causing drainage issues, and are more prone to overheating, stressing your plants, and damaging the roots.
On the other hand, wood is breathable, excellent at retaining water, and stays cool even in direct sunlight. Terracotta or ceramic is breathable, too, and does great even in environments with tight airflow. Meanwhile, glass pots are elegant, and their wide opening usually permits better airflow. The catch is they’re easily breakable, which means you need to handle them with better caution.
4. Get the Right Soil Type
Your soil type affects how it drains and the success of growing your plants. If your soil is too sandy and has little clay, it will have a loose structure, meaning it can’t retain water well. The spaces will allow the water to drain quickly, preventing your plants from absorbing the amount of water it needs.
On the other hand, clay soil is tight, remains wet and cold in winter, but dries out during the summer. While it benefits from high nutrients, its compact structure renders it harder to drain and makes it difficult for the water to reach deeper roots.
Silt is fertile and has good air circulation and water retention. It also drains pretty well as it has finer, medium-sized particles, making it excellent for growing crops. Loam soil combines all the best elements from sand, clay, and silt. Added with organic matter, it’s the best choice for container gardening, as the soil is easy to work with, high in nutrients, and offers good drainage.
5. Incorporate Materials to Refine Soil Texture
Apart from choosing the right soil type, you can also incorporate other materials to further improve soil texture and drainage like perlite, compost, and vermiculite.
Perlite is a volcanic rock that’s extremely porous. It retains a good amount of water, but permits excess water to get flushed away. It’s also permeable, allowing better air penetration and providing more oxygen to the plant’s roots.
Compost is another great additive, especially if your soil is too clayey or compact. It enhances soil structure as compost breaks and avoids soil compaction. By doing so, spaces open up in the soil where air can circulate and water drain better.
Meanwhile, vermiculite is a mineral that’s spongy and good at absorbing water. It retains water and nutrients well but releases them over time, keeping the soil damp and not drenched. A scoop of vermiculite is ideal, especially for crops that love to drink more water.
Adding rocks, shards, stones, or pebbles to the bottom of the container won’t do anything in improving soil drainage. While the goal of many is to create a reservoir that the plant roots can use anytime, it will only result in the soil getting soggy. Moreover, these materials take up valuable space at the bottom, preventing the growth of the plant’s roots.
Drainage is also useless if you’re overwatering the plants. Though you pick the right container and soil and incorporate the right additives, your plants will drown and their roots will rot if they’re consistently overwatered. Plants need water to live, but always research the water they only require. Through that, you can ensure that they’ll be receiving just enough to keep them healthy.