At the beginning of the pandemic lockdown, after experiencing the minor supply-chain disruption that it wrought, I took it upon myself to ease our dependency on supermarkets by attempting to grow some, or all, of our vegetables.
As much joy, and legitimate “self-care”, as gardening provides, actually producing enough food to support your family is an entirely different goal to pursue than “growing your own tomatoes”. A few grow bags of veggies is a wonderful hobby, but I quickly learned that supplying your own food is another matter entirely.
By the time I got started the spring season was already half over, so I rushed to get a few plants in place while evaluating what to do next. I bought seedlings at the hardware store and local nurseries to get going and planted them into two 4×4 grow bags; a mix of tomatoes, summer squash, peppers, okra, cucumbers, and basil.
Packed densely into these first two bags, my small garden was off like a rocket. Quickly squash and cucumbers flowered and overwhelmed us with produce. Those warm spring months in Texas are exceptional for cucurbits (squash, cucumbers, gourds, etc).
The 3 squash plants and 2 cucumbers in that initial round produced impressively and, for a hot minute, we had more than we could consume. But the peppers and tomatoes languished a bit and were very slow to produce. Needless to say, planting and farming are two different things. There’s obviously room for improvement in the details here but the reality is that while growing plants is easy, getting massive production is not.
A single bell pepper plant will grow a half dozen or so peppers in a season. That’s lovely, but we eat 3-4 bell peppers a week, at least. Making a dent in our food supply dependency will require better output, but more importantly, it was obvious that I needed more plants, and that meant more garden space.
So I expanded the garden. But as I did, I was also consuming a large amount of very useful YouTube education (thank you to all the urban farming content creators) which opened my eyes to (literally) an entire other dimension to urban gardening.
Once you’ve maxed out your garden space, as they say, you can only go up from here…
How to turn 16 sq ft of raised garden bed into 64 sq ft of growing area
Plants want to grow. They’ll work very hard at delivering their payload (fruits and seeds) in adverse, or challenging, conditions. As gardeners, we’re both custodian and customer, in different senses, so we have to seek a balance between what’s right / natural for the plant and what delivers us the most useful resource (produce).
Letting your plants run wild may give them the freedom that they deserve, but it won’t help you live off the food from your garden.
Conversely, ordering your garden into neat, industrial rows, spaced according to the generic planting instructions on the back of your seed packet, will also fail to maximize the food you can grow in your garden. Those instructions are accurate to a point, but aren’t designed to efficiently use the small gardening spaces that most of us have available.
Like in corporate hell, the two keys to maximizing your returns are synergy and vertical integration.
I say this ‘tongue-in-cheek’, but it’s actually true. Synergistic relationships between plants you grow together are important levers you can pull to increase your garden’s efficiency.
In this post I’ll show how to maximize your growing space by planting different species together according to their height and light needs and how to stake/tie lateral growers and train vines to climb vertically.
The science of anti-gravity gardening…
A typical 4×4 raised bed provides 16 sq ft of lateral growing space. You could conceivably fit 4-6 plants in this space, if you’re cramming them in beyond the typical planting instructions’ recommendations. That’s a small handful of daily produce, which is lovely, but isn’t going to make much of an impact on your supermarket dependency.
Now consider what happens if you add 4 ft growing walls on 3 sides of that raised bed (leaving one side open for access). That gives you 16 sq ft of growing space on each wall.
16 sq ft + 16 sq ft + 16 sq ft + 16 sq ft (original bed + 3 vertical growing areas) = 64 sq ft of garden space.
For example, I built 10 4×4 garden beds for 160 sq ft of raised bed gardening space. Then I added 3 walls to the majority of those beds (for simple math, let’s pretend it was all of them) bringing the total to 640 sq ft of growing space.
160 sq ft vs 640 sq ft… That’s a big difference.
Obviously you’re not getting any more dirt from the vertical walls, so you’re not adding any square footage to your planting area, just your growing area. But that’s sufficient –IF you supply enough compost or plant food, and the necessary minerals, bacteria, etc for more plants to flourish in the same dirt.
Teaching plants to stand up tall is easy.
Many plants don’t grow vertically in the wild, because there’s no point in fighting gravity in their natural setting, but it’s not hard to convince them with a little gentle training.
Each plant is a little different, based on their growing habits, but there are some general guidelines to vertical growing that are more or less universal.
The stem of a plant is the highway of nutrients flowing from the roots to the growing tip and is your greatest area of vulnerability with pests and physical damage. If the stem is badly damaged the plant will usually die, so it’s important to provide the stem with sufficient support.
This usually means staking the plant, or training it to climb a fence or pole (depending on its natural growing habits). Likewise, once fruit develops, you’ll need to provide support as the produce grows heavy as it ripens. Slings can be fashioned from old clothes, pantyhose, and other lightweight and stretchy materials, which can provide anti-gravity support for heavier fruits and veggies.
Fashioning vertical walls from sturdy fencing is your best defense against the pull of gravity but even chickenwire can work (that’s what I used). For difficult angles and especially heavy fruits, you can add additional support by putting a stake in the ground and typing/stapling a sling between the fence and the stake (with the fruit in between).
Plants in the wild, grow wildly. Left to their own devices, plants do what comes natural and they grow as many leaves, shoots, and suckers as they can manage.
This isn’t ideal for two reasons: First, lots of leaf growth means nutrients aren’t going to developing flowers and fruit. Second, when you have many plants growing in a small area, congested leaves and branches will block light from reaching plants under the top canopy and provide insects more access to move between the plants and infest your garden.
The solution is regular pruning to improve light and air flow.
Nutrients / Water Balance / pH
A lot of plants in a small space means your soil biome will be working overtime. Getting the right mix of nutrients and bacteria has been my greatest learning curve in vertical gardening…
I’m still honing in on the perfect ratio, but just know to watch for yellowing leaves, slowed growth, delayed fruiting (not due to pollination issues), and preferably, pH test your soil frequently.
Feed slightly less food than recommended but twice as often.
Precise details will depend on the food you’re using, etc. The point is to feed your plants A LOT more than you typically do -because there are a lot more plants using the same soil.
Each type of plant grows in a slightly different shape and to different heights, etc. so if you grow too much of one type of plant you won’t be able to maximize your use of the space. By growing a variety of complimentary (guild/companion) plants with different growing habits in the same bed you can use every nook and cranny of your space.
Picture tomatoes growing in cages in the center of a 4×4 bed, with vining cucumbers, squash, and “pole” bean varieties growing on the inside (and outside) of 3 vertical walls on the outer edge of the box. Cages or stakes and regular pruning ensure the tomatoes don’t sprawl, and the vining plants will cover the outer edges without competing for light (caveat: see next item).
This is just one example. Look through companion planting or guild planting schemes and pick plants of varying heights that grow well together and create your own combinations.
Growing a lot of plants in a small space means that your plants will compete for light. A little friendly competition is healthy but you want to keep an eye on your most aggressive growers to make sure everyone’s getting the light they need.
Fundamentally though, you can only add 3+ walls to your beds if your growing space receives several hours a day of top-down unimpeded sunlight.
If you’re working with directional light only, because you’re up against a wall on one side, or similar, you’ll need to be careful not to create shaded areas once your plants fill up your vertical walls.
It’s simple really.
Vertical gardening requires a lot of maintenance. It’s not for the faint of heart or those short on time. You’ll need to frequently monitor, prune, feed/adjust minerals, pH test, and so on. You’ll also need to be clever about supporting the growing fruits with slings, stakes, cages, etc.
Typical rules don’t apply and you’ll need to plan ahead. Success with vertical gardening requires the ability to think ahead, imagining what your space will look like when it’s filled in with greenery. It also requires agility and leaving yourself enough room to adapt to unexpected circumstances.
I discovered (a little late) that leaves were yellowing in all my boxes and that the problem is a high pH due to overwatering because of the heat. The heat here in Texas demands extra watering and my beds are packed full. Gardening is full of delicate balances like this and keeping a keen eye on the little details is the key to getting a lot of healthy production in a little space.