Container Gardening: Ins and Outs

Container gardening is a fun, affordable way to grow plants for both enjoyment and consumption.  Because there are so many options out there, we wanted to simplify things for our customers by breaking it down into four basic considerations.  As always, call us (913-397-0594) or email us ([email protected]) with the details of your particular situation and we're more than happy to help you develop a plant that's right for your garden!

Container Size

One of the trickiest parts of container gardening is knowing what size garden pot to use. Garden containers are typically measured in either inches or gallons. Inches refer to the pot diameter, or the distance across the top of the container. Gallons refers to the volume of grow media that can be held in the container.  When selecting a container size, consider these three factors:
First, evaluate how big your plant will become when fully mature. You want to make sure you have a pot large enough to handle a root system that will support the size of plant you're growing without becoming root bound. If your pot is too large, the soil dries slowly, making your plant more susceptible to root rot. If your pot is too small, the soil dries so quickly that you'll be challenged to water frequently enough. Your plant could become root-bound and exhibit stunted growth.
Second, evaluate the type of root system your plant will develop. Some plants such as succulents, have very shallow root systems and don't necessarily need the volume of grow media that a plant such as a pepper, which grows deeper roots, would require.
Third, evaluate the time frame at which it will take your plant to reach its desired size. We always recommend starting your plant in a smaller container than its final resting place and allowing it to grow until it reaches the capacity for that pot. Then, you would transplant into a slightly larger container to allow continued development. This will help you make the best use of your space rather than putting your plant in a pot that may take years to fill out. It will also encourage healthy root development and limit the risk of root rot. When transplanting into a larger pot, we typically recommend moving up approximately 2-4 inches in diameter.
How frequently you pot-up into a larger container is determined by the rate at which your plant grows. Slower growing plants can be transplanted into larger containers much more infrequently than faster growing plants, but they also allow for more incremental steps to get to their final destination. This provides the ability to further maximize the room in your grow space.
Here are a few examples of what would grow well in different sized pots:
  • A tiny 3" pot would be great for succulents.
  • A smaller pot around 1-3 gallons would be ideal for strawberries, lettuce or Swiss chard.
  • A medium pot around 5-7 gallons would be ideal for cabbage, collards, carrots, and some larger herbs such as rosemary or lavender.
  • A larger pot around 8-10 gallons would be ideal for tomatoes, peppers, broccoli, cauliflower and dwarf citrus trees.

Container Material

In addition to varying sizes, planters come in all different materials as well, each having their own advantages, disadvantages and price points.

  • Plastic containers are inexpensive, lightweight and durable. Because plastic isn’t porous, it keeps soil moist, which means less watering. However, dark colored plastic can increase the temperature of your soil significantly when placed in direct sun light and some plastics may become brittle over time.
  • Fabric grow bags allow you to grow crops anywhere and tend to be fairly affordable. They are flexible, lightweight, and allow plant roots to breathe. They don't create excess heat in your soil and prevent overwatering because excess water simply drains through the bag.
  • Terra-cotta pots come in many sizes, shapes and styles. Un-glazed terra-cotta is porous and will dry out quickly. If you are putting this type of pot in a bright, sunny area, we recommend using a glazed version which will do a better job of holding moisture. Small to medium sized terra-cotta pots are very affordable, popular options. As you move to larger pots in this category, the price can jump significantly.
  • Metal containers make for a great look for many spaces which also makes them slightly less of an affordable option. Be cautious that the metal will heat your soil, and note that you’ll need to water more often.
  • Wood, concrete and ceramic provide good insulation for soil, moderating soil temperature and moisture loss, but they can be super heavy and tend to be pricier options because of their decor factor.
When choosing the material and style of a planter that will work best for your plants, take into account where the container will be placed, how much sun/light is available, whether aesthetics are important and your budget. Regardless of the container you choose, be sure it has adequate drainage to avoid water logged soil and root rot issues.

Grow Media

Grow media is anything that will hold a plant’s root structure in place and provide support to the plant so it can grow.

Some media are completely inert, meaning they have no nutritional value. With these, you will need to add the basic nutrients and any amendments that your plant requires to grow. While this means more work on the part of the gardener, it does give you complete control over your plant's inputs.

Other media comes premixed, containing essential nutrients and minerals. While this reduces the need for additives, not all premixed media is created equal.

Here's a breakdown of a few popular media choices, beginning with inert media:

  • Coco Coir is made from the outer husk of coconut shells. It's a light-weight medium that has good water retention without becoming too soggy. It is much harder to over-water compared to soil and has great air capacity, which helps with root growth and nutrient uptake.
  • Clay pebbles are great for hydroponic systems. They are pH neutral and do not contain any nutrient value. This is also a re-usable option thanks to its ability to be cleaned and sterilized.
  • Vermiculite & Perlite: These mediums are similar in that they are made from porous rock material which gives them excellent water retention qualities. Vermiculite is a mined mineral whereas Perlite is light-weight volcanic rock. They can be used on their own, or can be mixed in with soil or coco to give better water retention and air capacity to those mixes. Keep in mind, though, that because these are mineral based, they do contain trace nutrients, unlike some of the other inert media. We consider these inert because they do not supply sufficient nutrition to fully grow a plant.
  • When you get into premixed options, such as soil mixes and living soils, these often contain other ingredients such as sphagnum peat moss, organic matter, worm castings, bone meal, beneficial microbes, lime and guano biproducts, to name a few. These mixes allow for a minimal need to introduce additives and supplements to the media. Some of these mixes have been developed to last the life-cycle of a plant, while others will have a higher need for supplemental nutrients.
  • Other soil mixes such as Pro-Mix have very little nutrition (if any), which allows you full control over when and what you are feeding your plants, but these do require a significant need for nutritional additives.

There's no right or wrong media to use in your container garden as long as you have an understanding of how to properly use that media in conjunction with your plant's particular need for nutrition.


It can sometimes be difficult to gauge how much water your container garden plants need. There is a fine line between soil that's either too dry or too soggy - both can be detrimental to the health of your plants.
Knowing how frequently and how much to water your container plants is usually a matter of trial and error. It's important to be both patient and observant during this process until you identify your particular plant’s preferences. Watch how your plant responds throughout the day to each watering. If it was droopy before you watered and has perked back up after watering, it was probably thirsty. If it stays droopy, the soil might be too saturated and you should try letting it dry out a bit before the next watering.
Here are a some tips to make watering your potted plants a little easier:
  • Use glazed pots to help prevent evaporation. Also, adding a top layer of mulch or rocks will help slow moisture loss.
  • Set up a drip irrigation system for watering your container plants. This allows for slow, even watering that the soil can absorb before it all runs through the pot and out the drainage holes. There are a wide variety of options available to accomplish this, from digital, fully automated solutions, to mechanical devices, to simply using the power of gravity.
  • Apply water in early morning or late evening when temperatures are cooler and direct sun will not cook off the moisture before it can seep down to the roots.
  • Keep an especially watchful eye on outdoor container plants. Higher temperatures, direct sunlight and wind tend to dry the soil quickly.
  • The amount of water may vary from plant to plant so it's ideal to find out the average moisture needs of your particular plant. We recommend using a moisture gauge. These are very useful tools for container plant watering. The gauge has a probe that you stick into the soil and gives you a reading that rates the soil moisture level.
  • For smaller plants and light-weight pots, learn the difference in weight between soil that is fully saturated with water and soil that is completely dry by simply picking them up. Over time, you can become your own moisture gauge just be giving your plant a quick lift and judging whether or not it has enough water in the soil.

Never Stop Growing

No matter what container size, material, grow media or watering method you choose, pay careful attention to how your plant responds to each.  This will help you learn what works and what doesn't as you continue to expand your garden. Most importantly, have fun and never stop growing!