Lots of people have taken up container vegetable gardening in the past few years. It’s a lot less work than a full-blown backyard garden, and who would think twice about not having to weed all that space? Growing in containers can also mean using a lot less water. Plus it’s more accessible for seniors and those with physical handicaps since the plants aren’t way down on the ground. But buying containers gets expensive – especially when they’re big enough to hold a full size tomato plant. And so the ingenuity of the repurposing and DIY crowd has found a myriad of impromptu vessels for growing herbs, flowers and vegetables too. However…
Just because it holds potting soil and drains does not make it the best thing for container vegetable gardening. It might be frugal. And it can be classified as resourceful, eco-conscious, or artsy and trendy. But are you getting the food that plant could give you in optimum growing conditions? Or have you reduced it’s vigor, immunity, and fruiting capabilities? Not much cost savings in having to battle drought, disease or pests, or getting a dismal harvest. Sometimes, penny pinching winds up carrying a bigger price tag in the end.
Container Vegetable Gardening is About the Plants!
- They have no patience for being cute or stylish.
- Don’t expect them to be convenient, or to keep the deck clean and dry.
- Never ask them to tolerate cramped, too dry, or too wet conditions.
- You can’t expect plants grown for food to do a dollar’s work for a dime.
To perform at their very best, plants have certain requirements. Sufficient space above and below the soil line, good nutrition, good support, good drainage, fresh water, consistent moisture, and lots of sunshine.
Give Them Space
Yes, you can cram 4-6 flowering annuals into a container that’s 18-24 inches wide. You’ll have to water a lot, but it looks so cool! You can’t do this with plants grown for food. Even in a raised bed – overcrowding and insufficient root space will lead to a reduced harvest and fruit size, and worse. At the very least, you’re stressing them out.
Plants that are packed together flower less, and only on the surfaces that get good sunlight. The more flowers you have, the more fruits your plants produce. Not to mention it makes harvesting without damaging the rest of the plant more difficult. And when there isn’t good air flow through the stems and leaves, you’re creating the perfect environment for disease to set in. If you live in a humid climate, it’s also impossible to apply fungicide to keep your plants healthy despite environmental conditions. You can forget keeping tomatoes free of disease caused by lots of rain, or heavy dew and chilly night air. Also note that with excellent air flow, you’ll find that tomatoes in container vegetable gardening are less prone to blight and leaf spot… because the leaves and soil surface can dry easily.
The Root Zone
Lots of plants will live in a container that is much smaller than the space the root system would naturally occupy in the ground. But in doing so, it doesn’t allow the plant to reach full size. The less room the roots have, the closer to a bonsai specimen you’ll get. And a scrawny one at that.
There will be less branching, and consequently, less flowering and fruits forming. And the fruits it produces will be smaller than the same plant grown where its roots can develop properly. Sure, you can grow patio or cherry tomatoes in a tiny container, but will that give you a slicing tomato? You can’t make a BLT from itty bitty fruits! You need a slab. And what about harvesting enough tomatoes to provide food to become more self-sufficient?
Moisture retention is a huge problem in vegetable container gardening. Especially in plastic planters where the only drainage is a big hole in the bottom, and the potting mix is engineered to make all the water get there fast. The more roots in that growth media, the more water and nutrient demands you’re going to have too. So if you cram too many plants into a container, or try growing a huge plant in too small of a pot – they’re going to suck up a lot more water. Plan on watering at least twice a day. If your container garden gets too dry, the result could be a lot bigger than some wilt. Inconsistent water leads to things like blossom end rot, blossom loss, and growing tip or stem damage.
Fighting Drought with Containers
Using containers with no drainage hole isn’t the solution. Too much water will definitely happen then, especially when it rains. This leads to issues like cracked tomatoes, not-so-hot chili peppers, suffocation, and root rot. If you’re trying to keep the patio or deck clean and dry – put a saucer or tray under it to catch the dirty water. Plants that can’t breathe produce little to no food at all, not to mention being downright hideous looking.
Then there’s the self-watering planters. Even these can cause you crop problems. The water down there is and stagnant. Like a mucky mud puddle in constant shade in high temperatures. There’s no air flow, and it’s hot as hell inside that plastic tote bin when it’s 80-90 degrees outside. And is your container garden sitting on pavement? It’s even hotter in there than when it’s sitting on soil. This anaerobic condition breeds harmful bacteria. They love hot, wet conditions. Consider how your plants feel about hot, skanky water. They may wick moisture up from ground soil, but it’s drawn up through natural filtering at much cooler than surface temperatures.
The thing is, you’re trying to do advanced gardening using all the wrong stuff. Stop trying to be futuristic with outdated basic materials.
Advanced Container Vegetable Gardening
How would you feel about defying the laws of container gardening and getting a better harvest? You can. Without drainage holes. Using topsoil and compost and/or cow manure. Now you’ll have excellent moisture retention with good drainage and air flow in a food safe container that you can leave outdoors all winter. The container will last anywhere from 3-10 years… depending on what brand you buy. Warning: it won’t be chic, and it will make your wood deck wet constantly without a saucer. But your veggies will be ecstatic, as long as you don’t overcrowd them. And you won’t have very many weeds to pull.
The secret? Fabric pots and planters. The frugal gardeners out there will scour the world to find the cheapest ones possible. Sorry, but that’s not the economical approach to this scenario. You’ll be replacing your pots and planters pretty regularly. Trade up a few at a time if you must. Smart Pots are the longest lasting ones available, giving you 7-10 years of durable use. There’s a reason they cost more than those lower priced knock-offs. Thin fabric and lower quality materials (like recycled plastic bottle fabrics) will not hold up well. Some will only last a summer or two, so in the end, you’ll spend much more than using the best option from the start. People who use the Smart Pot brand report using them year around for 7 years or more and they’re still in great shape.
Fabric containers come in all sorts of sizes with varying widths and depths. I’ve grown tomatoes in them, and the results were phenomenal. After a couple of years growing everything in straw bales, I’m switching to everything but tomatoes grown in Smart Pots. Growing in a 70/30 mix of black topsoil to composted cow manure gives you excellent air flow for roots while maintaining both drainage and moisture retention. It’s a lot cheaper as a growing medium than potting mixes, and plants go nuts in it. But the straw bales’ heat gives me an earlier ripening tomato harvest. Next year I’ll test straw versus black fabric pot results to see if it gives me earlier warm root conditions with less hassle.
I know a #30 is great for a huge tomato plant, but what about everything else? Figuring out how many pots and what sizes I need, led me to a great planting chart put together by Les Urbaincultures. They’re an urban farming company in Quebec that does a ton of growing in Smart Pots. In fact, Nicolas Ste-Marie from their Montreal office wrote an article about it for Issue 6 of our print magazine. So, they’ve got the good harvest planting for container vegetable gardening down to a science.
One other cost saving benefit to container gardening using real soil is you don’t have to replace it every year. Over the winter, the top 2-3 inches of dirt in the Smart Pot blows away, but that’s okay. You want to replenish the compost/cow manure content each time you plant to give your plants the best growing environment. I shovel out about 60% of what’s in the container into a wheelbarrow to amend it. This makes it a lot easier to mix the two together well with a shovel. Saves the container walls from wear and tear too.
Once you see how much faster, and bigger your plants grow – you’ll never go back to plastic for growing veggies.
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