Growing container plants is a way for avid gardeners to grow even more plants. After all, if you love to garden you can’t have too many plants, right? Container plants can fit into spots where planting in the ground isn’t possible and they can add color to otherwise drab corners of the yard.
Container plants do need a bit more care than plants grown in the ground. It is important to choose the right potting soil for container plants and the watering and fertilizing schedule for container plants will differ from the requirements for plants grown in the ground.
To help ensure that your container plants get a good start, they’ll need a good home. There are a wide variety of pots available for container plants, but in reality, not all of them are truly suitable homes for plants. A good pot for container plants will provide adequate drainage without allowing the planting medium to dry out too quickly, and it should last more than one season.
Wooden pots look especially nice but they have a tendency to fade and eventually rot. If you want to house your container plants in wooden pots, look for pots made from cedar or redwood. These woods are resistant to rot and have a longer life expectancy. Avoid using treated wood to build your own pots for container plants, as the vapors released by treated lumber can be toxic to plants.
Terracotta pots come in a variety of sizes and can be quite attractive when they are grouped together. Terracotta pots are porous and can allow the planting medium to dry out quickly, so container plants in terracotta pots will need to be watered more frequently.
The weight of a small terracotta pot will help prevent it from being blown over in windy conditions, but a large terracotta pot filled with soil and plants will become very heavy and difficult to move around. If you choose to use large terracotta pots for container plants, it would be wise to place the pot on casters so it can be easily moved around.
Plastic pots are lightweight and easy to handle. They also come in a variety of colors and shapes and are generally less expensive than ceramic pots. Be wary of very cheap, flimsy plastic pots though. These can lose their color and become brittle after extended exposure to sunlight.
Container plants will happily reside in a glazed ceramic pot if it provides ample drainage. Like terracotta pots, glazed ceramic pots can become heavy when filled with soil, so these too can be placed on caster wheels if they need to be moved around. Unlike terracotta pots, a glazed ceramic pot won’t absorb and lose water through its walls.
Choose a pot in a size that is appropriate for your container plants, keeping in mind that the little plants that are potted up in the spring will grow much larger by the end of summer. Pots that are too small will limit how much the plants can grow and they also tend to dry out too quickly.
Plants that will grow large need larger pots, while plants that are meant to stay small, such as bonsai plants, will need much smaller pots. Tomato plants are quite small when they are planted, but as they grow they will develop a large root system. A large pot with a capacity of seven gallons or more is required for plants that will grow large.
Any pot for container plants will need to provide adequate drainage and should have one or more drainage holes in its bottom. Drainage holes should be about a half-inch across, and the pot should have a bottom lip so the drainage holes don’t sit flat on the ground. If the drainage holes are flat to the ground, excess water won’t drain out well. Placing the pot up on bricks or “pot feet” would improve the pot’s drainage ability.
If you’re concerned that potting soil will sift out through the pot’s drainage holes, the bottom of the pot can be lined with paper coffee filters. Water will still drain through the filter, but the soil will stay in place.
A good potting soil can make all the difference between healthy, lush plants and sad, spindly container plants. Good potting soil will drain well but not dry out too quickly. The goal for healthy container plants is to keep the soil around the roots evenly moist. Well-rotted compost from your own compost pile makes excellent potting soil. Bags of compost from the hardware store may or may not make good potting soil.
Some are too light, some are too acidic, and some are high in clay and too heavy for container plants. Before buying bagged compost, ask the store manager if they have an open bag you can examine. Grab a handful of the compost, examine it, and give it a squeeze in your hand. If the compost holds together in a ball, you don’t want it for your container plants. It will be too heavy and won’t drain well. Good compost will have little bits of organic matter in it and will feel light and fluffy.
If compost isn’t available, you can purchase a good quality potting mix or make your own. A mix of equal parts coarse sand, rich, loamy garden soil, and peat moss will make good potting soil. Better yet, purchase a soilless potting mix. Soilless potting mixes are lightweight and will drain well, and they won’t contain weed seeds.
Above all, avoid using garden soil by itself for container plants, even if it’s wonderful soil that your garden plants love. Garden soil in a container will compact and limit drainage and aeration for the plants’ roots.
Large containers will require large amounts of potting soil. This can not only make the container very heavy, but it can also get expensive if you have to purchase potting soil. Lighten the load on your back and your wallet by adding some material to the bottom of the container before adding the potting soil.
Crushed aluminum cans, foam packing peanuts, or plastic bottles can be used as fillers to take up some space in the bottom of very large containers. This material is not a substitute for drainage holes in the container though. If the pot has no drainage holes, the plants should be potted up in a slightly smaller container that does provide drainage, and that container can be slipped inside the pot that does not provide drainage.
Do not fill the container level to the top with potting soil. Instead, leave at least an inch of space between the top of the soil line and the top of the container. This will provide room for watering, so the water will soak into the soil instead of washing out over the top of the pot.
Improper watering causes the most problems with container plants. Container plants tend to dry out more quickly than plants in the ground, and inadequate moisture will cause them to wilt, give up and die or just grow poorly or not at all.
There is no strict rule dictating how often and how much container plants need to be watered. Factors to consider when determining how often to water container plants include the size of the container, the drainage ability of the potting mix, the weather, and whether or not the container is porous.
In general, small containers will need to be watered more frequently than large containers. In hot weather, container plants will need more water than they require in cooler weather. During the heat of midsummer, container plants may need to be watered daily, but by early fall they may need more moisture only once a week. Above all, the plants prefer even moisture, and to keep them looking their best, they should be watered before they show signs of wilting.
Container plants should be monitored daily. The best way to know whether or not a plant needs water is to poke a finger down into the potting mix. If the top inch of the potting mix feels dry, the plant needs water. Be sure to give it a good drink, not just a sip. The entire mass of potting soil should be moistened so even the deepest roots get a drink. When water begins to drip from the container’s drainage holes, the plant has adequate moisture.
Adequate watering also leaches the soil, meaning it washes away any potentially harmful buildup of salts in the soil. These soluble salts can originate in fertilizers and sometimes even in the water itself. If you’ve seen a white, chalky residue accumulating on pots and the soil surface, this is a buildup of soluble salts.
A buildup of salts in the potting mix can cause root injury and burned leaf margins on the plants. Thorough watering with collected rainwater or well water will help wash away the salt buildup. Watering with softened water will increase the number of soluble salts in the soil.
Container plants will need regular fertilizing to keep them looking their best. Many potting soils contain slow-release or timed-release fertilizer beads that will supply nutrients to the plants for three to four months. These little fertilizer beads are sometimes mistaken for insect eggs but be assured that they are there to help feed your plants.
If your potting mix does not contain fertilizer beads, liquid fertilizer can be added to the soil when watering the plants. Your plants will appreciate it if their potting soil is moistened slightly before fertilizer is added.
Fertilizer is washed out of the container each time it is watered, and it needs to be replaced often. Container plants can be fertilized with a full-strength liquid fertilizer every two weeks, or with half-strength fertilizer with every other watering.
Check the labels and buy a well-balanced fertilizer that also includes trace elements that plants need for the best performance. Foliage plants like fertilizers that are high in nitrogen, while flowering plants and vegetables perform best with fertilizers lower in nitrogen but higher in phosphorus.
Now that the container plants are living in terrific potting soil and getting adequate moisture and fertilizer, they will grow like gangbusters. They may grow so well that they become a bit leggy and may appear to be outgrowing their pot. A bit of grooming will get the plants back into shape.
When a plant starts to become too tall or leggy, pinching it back will cause it to fill out and become bushier. To pinch back a leggy plant, simply pinch or clip off the plant’s growing tip. This will encourage the plant to develop more side shoots.
As blossoms on flowering container plants fade, they can be deadheaded to keep the plant looking neat and attractive. This also prevents the plant from producing seeds, and once some flowering plants produce seeds they think their job is done and they bloom less. Once the flowers begin to fade, just clip them off.
Grooming container plants doesn’t need to take up a lot of time. It can be done in just a minute or two while the plants are being watered. Spending just a little time on grooming will keep your container plants performing beautifully, as they should be.