The pot is the home of your plant and will determine how much you will yield by harvest time. When farming in the city, it is important to take your lifestyle and space into consideration during the planning stage. Other elements like the amount of time you have to dedicate to caring for and watering your plants will also come into play. We are busy people, and anything we can do to reduce the amount of time we spend doing manual labour will pay off.
What’s the criteria for the best planter?
🪴 Root size, pot size
Firstly, determine how big the root of your plant will be — you want to avoid “root bond,” which occurs when the pot is too small for the amount of roots needed for the plant to grow. The caveat is that size of the root system, not the plant itself, determines pot size.
For me, the rule of thumb is the bigger the pot, the better when it comes to growing food. Larger pots can hold more water. Certainly, you might be using more soil than you’d expect, but the plant will grow to its fullest potential. Think of it as providing a big, spacious backyard for your puppy to run around and grow up. Your plant will likewise be happier with a larger home.
A study found that doubling pot size allowed plants to grow 43% larger. Another thing to consider is plants that tend to grow really big also need really big containers.
🚰 Drainage: avoid root rot
Too much water is one of the leading causes of death to many plants. If you overwater, the air pockets in the soil will fill with water and the plant will drown, a condition called “root rot.” Most plants don’t thrive in stagnant water, so your pot needs a drainage hole at the bottom that allows water out and air in.
✨ Cachepots keep things pretty
With all these concerns, another issue is a cosmetic one: after all, you want your plants to enhance the atmosphere of your indoor or outdoor space. Thanks to double potting, you can have the best of both worlds. An ornamental cachepot will allow you to retain functionality on the inside and a beautiful appearance on the outside. Be sure to check that the material of the cachepot is food grade.
By double potting, you can hide the less attractive container with holes that allow for drainage. A cachepot doesn’t need drainage holes, but you need to make sure that the pot is large enough that the water reservoir does not cover the soil on the inside. This takes us to the next point.
💧 Water reservoirs
At the bottom of the pot, there is space to collect water. The advantage of a water reservoir is that it drastically reduces the frequency of watering. The liquid can sink to the bottom of the pot and sit there, on hold, waiting for the plant to suck up moisture when needed.
As aforementioned, good drainage is essential and excess water can overflow to a reservoir. It can be achieved — with almost any pot — by adding stones to the bottom of the pot, which are there to prevent the soil from getting over saturated with water (remember we want to avoid root rot!). Sometimes it can be as simple as adding a saucer to the bottom of the planter.
Overflow holes make watering a real easy process, too. This is simply an opening in the side of the pot that will leak water out once the reservoir has reached a certain amount of water.
- Less frequent watering
- Water is available for the plant when needed
- Look out for stagnant water
- Can be as easy as adding a saucer to pot
🍽 Food grade materials
This is a critical step. Since we are focused on growing food, we need to make sure the material of the pot is food grade. This means it won’t leak toxins into the soil while it is exposed to water and sunlight. Understand where you will have your pot: if you are hanging it, plastic might be the way to go. If it is in a windy area, terracotta or concrete planters will keep the plant from blowing away.
Air pruning pots
This is a new concept that entered the horticulture game via the cannabis industry — and I have personally witnessed the difference. With air-pruning pots, the edge of the pot is either a porous fabric or has many dimples with holes exposed to the air, like a golf ball). As the plant grows, the roots will reach the edge of the pot and become exposed to air, which will effectively trim the ends of the roots to promote growth. When its roots are pruned, the plant won’t bind around the pot and so continue to grow.
Plants like tomatoes have a massive root system and by the end of the growing cycle, they will nearly take up the entire pot. An air-pruning pot will put more energy into growing and yielding fruit rather than expanding the root system in its tiny home.
A drawback of this type of system, however, is that holes in the pot will be exposed to insects that might infiltrate the root system and cause problems.
- More oxygen to the roots
- Prevents plant from getting “root bound” via air-pruning from the sides
- Air pruning pots prevent overwatering thanks to holes, but that also means you will end up watering more often
- Bugs can be an issue as they will come in through the holes
Capillary or wicking systems
Pots that let to water from the bottom up — wicking pots — are also encouraged. The capillary action of the soil pulling water upwards will keep the soil wet but not too moist, while also reducing fungal and disease development that often occurs when watering from the top of the pot.
Wicking can be achieved in many ways, from a self-watering mats to pots with watering tubes. These tubes are openings where water can be poured in from the top, but waters the plant from the bottom.
What planters meet the above criteria?
All this is a lot to take in, I get it! To make your pursuit easier, I have written a review of all the planters that fit the bill and are amazing for growing food.
Updated July 20, 2021. Originally published April 20, 2019.
