This ties to something I was thinking about yesterday, while wandering around neck deep in brambles with a brush-cutter.
We live in a steep sided river valley in northern Portugal, and the place came with 5 Ha of woodland, on a SE facing slope.
We’ve only lived here some six months, and we’ve gradually realised that almost every square inch of the hillside has been terraced - the process is to build hefty walls along the contours, and then let the hill slump into the gap, making a level growing area.
The thought that occurred to me/thing I noticed was just how much IR the wall I was working next to was emitting after the sun went down - felt like a patio heater pointed towards my face from a few meters away. I then realised that the reason that they’re all so incredibly overgrown is likely the combination of thermal mass warming the surrounding area, water being forced to ground level at the foot of each wall, and accumulated mulch being trapped by each wall.
I can’t count the number of times since starting here that I’ve marvelled at the simple ingenuity applied towards working with nature, from the terraces creating a better growing environment than the now-farmed planes above us, to the positioning and orientation of the mill - it’s situated at the one point along the bank that gets sunlight all day, all year, apart from two weeks in midwinter - which just happens to coincide with an outcrop that they co-opted into a weir.
Anyway. I wonder to what extent the idea of a fruit wall stemmed from people seeing this sort of terracing, and deciding to do it without a hill.
High efficiency houses use this principle (thermal mass) behind glass to soak up the sun during the day and to release the warmth during the evening and night. More complex systems use roof and wall collectors and store the heat underground in large amounts of insulated thermal mass.
If you’re willing to share, I’d love to see photos! This sounds very much aligned with permaculture philosophies (which can be extrapolated to areas of life beyond food production) [0]
May I ask for a little more information about these designs, in how they're structured and if it's local only? I've been thinking about buying land in, you guessed it, northern Portugal, and I'm interested in mixed old-agricultural and forested land nearby a river. Sounds pretty similar to your area!
What are the terraces made of? Landscaping blocks? Wood? Rock? I have a nice south facing hill that i would like to terrace but don't know what to use for the walls of the terrace.
This is mostly about the heat absorption properties of walls. Another property of walls, which they do allude to, is the protection from wind, which can be even more important in more hostile environments. When wind hits a wall (or obstacle) there is a period of space behind the wall where the shelter is actually higher than the wall. I think this is called the Law of the wall[0] in fluid dynamics. If you place your fruit trees the optimal distance from the wall you can provide maximum shelter, and if you place the 2nd tree an optimal distance from the 1st tree then the 1st can shelter the 2nd, and so on. My parents were able to use this theory to grow some of the only fruit trees on a windswept island notable for its almost complete lack of any sort of trees.
So while a walled garden has something of a negative connotation in technology, in horticulture it seems much more positive. Interestingly, looking at the definition of walled garden on wikipedia "A walled garden is a garden enclosed by high walls for horticultural rather than security purposes"[1] (emphasis mine).
"Another issue with a solar powered greenhouse is the lack of a CO2-source. In modern greenhouses, operators aim to have a CO2-level at least three times the level outdoors to increase crop yield. This CO2 is produced as a byproduct of the fossil fuel based heating systems inside the greenhouses. However, when no fossil fuels are used, another source of CO2 has to be found. This is not only an issue for solar greenhouses. It’s also one of the main reasons why geothermal energy and electric heat pumps are not advancing in the modern glasshouse industry."
I'm sure I remember reading about some kind of solar setup that used part of the electricity generated to extract CO2 from the air and feed it into a greenhouse. Seems to be hard to google for, given that CO2 and greenhouse automagically translate to climate change, instead of actual greenhouses.
I wonder if anyone uses greenhouses as carbon capture for traditional power plants, rather than running their own mini-power plant mostly for the CO2 output.
I live in Paris in I have been very aware of the old peach and raisin we used to have from neighborhood villages in East suburbs ( Montreuil is touching périphérique so just an arm away from Paris).
It was the 19th century. wethear could be cold like minus 8 for a few days in winter so yes thick wall protected them also from extreme cold winter waves.
But do not forget that,at that time, Parisian did not often eat peach or raisin.
I am quite sceptical that indoor farming or other (re)new trendy technique could ever produce mass market fruit we are used to have.
In-season, local fruit, is a million times better anyway. We’ve traded taste for shelf-appearance and the ability for fruit to travel from New Zealand to California. If people really want strawberries in January (and as a parent of young picky eaters, believe me I understand) they’ll just have to pay a carbon tax on it.
Fun. I've grown, uh, certain plants. Everyone said you should do it indoors, in a controlled environment. But with the availability of sun I have it makes little sense to waste so much energy on growing them indoors.
Last year I had 6 plants grow perfectly happy outdoors, and these were from seeds of plants bred indoors for probably generations. The last plant was ready in freaking November.
Some of them cross pollinated (yeah, if you buy "feminised", that's not a guarantee lol), and now I have a few hundred new seeds that I plan on growing outdoors come May. Should be fun.
On that note, everyone around here has a small garden, mostly staple vegetables and fruits. But the soil is perfect for anything. And yet I see people growing stuff in controlled greenhouses even in the summer. Wasteful, if you ask me.
In Germany this is called "Spalierobst" and is still widely practiced. As far as I know certain fruits like apples are also produced on plantations with trees that are forced into specific shapes for easier harvesting.
Great article. Query though, it says “Protruding roof tiles or wooden canopies often shielded the fruit trees from rain, hail and bird droppings“
I get most of that but are bird droppings really a problem?
If the greenhouses are built wall-to-wall like pictured in the article, the thermal losses through the walls should be minimal? Only the outermost perimeter would need any insulation
It is about thermal mass and staying above a minimum temperature. An infinite greenhouse has a better insulated roof (compared to no roof) but lower thermal mass.
They have fruit walls in the George Washington museum at mont vernon in Virgina. At first I just thought is was for adorning the garden, but it is very practical too.
“ This website runs on a solar powered server located in Barcelona, and will go off-line during longer periods of bad weather. This page shows live data relating to power supply, power demand, and energy storage.”
Does anyone have a handy 20 minute guide to getting started with balcony farming for apartments?
1) sunlight requirements, different for plants
2) soil and replacement.
3) water, frequency and outlet.
What are some other things to care about? Where do I get soil? Is it okay to dig from an existing farmland? I live quarter mile from a river. Should I collect from river bank?
The limited area you have at your disposal will not be able to actualy feed you. With intensive farming one would need around 200 - 500 m² to produce the calories required.
So with balcony farming I'd recommend focussing on greens that make your meals better. Microgreens are easy to do and add a lot of flavor to your salads and meals. For the rest herbs and leafy greens are the way to go. Herbs as perennials can be grown in soil pots. The plants in pots you can get in the supermarket usually do not last long. They are produced for maximum harvest yield at market time and usually have a hard time when trying to keep them. Get some heirloom seeds or cuttings and make soil from coco coir and perlite. For leafy greens hydroponics can make sense. Jeb the gardener on YT is funny and informative. It is easier to automate hydroponics than soil culture. Chili Chump on YT has a good series on that.
Consider running a bokashi indoor compost. The liquid collected from that is excellent organic fertilizer for the coco coir and the hydroponics.
Start small. Scale up as you gain more experience. Microgreens have a 10 - 14 day culture, so starting with those will give you a fast turnover and quick iterations for improvement. Try to purchase seeds in bulk, otherwise cost will be prohibitive. Organic seeds for commercial growers come in larger quantities at a reasonable price. Try to source those.
Me and my wife have grown stuff on the balcony, but the main reason that we don't anymore is that we go away for four weeks during the summer where there is the most need to water. We can grow things in the spring and in the autumn, but we miss the warmest period in the middle.
We bought four large clear plastic containers from IKEA that are intended to store stuff under the bed, drilled holes in the bottom of two of them for drainage, and put them in the other containers. We filled them with LECA pebbles and dirt, and watered with large PET bottles. It was all very easy.
One summer we grew kale in one container, but were discouraged when we harvested it and only had enough for one pie. Your first sentence triggered this memory, which is the point of my comment. Growing kale on that small scale was terribly inefficient, and the amount of work to water it far surpassed the joy of eating the pie.
Another summer we had curled leaf lettuce that was much better than kale. It grew so quickly that we could continuously harvest it and still have more growing. Of course you can't eat it for the calories, so it's just for fun.
We've also had windowboxes on the inside of the balcony railing with flavorful sallads and herbs, like rocket sallad, basil, chives, and so on. As you say, those add a lot to a meal without taking up too much space, and are easy to start with.
Maybe you mean square feet instead of square metres?
Less than 50 sq m (approx 500 sq ft) per person using conventional row gardening would be the norm - and with intensive gardening, that same plot could support a 4-person family.
Yea, but there's one problem I have with this estimate. It requires near perfect efficiency. There's almost no buffer here for poor crop yields, less than ideal climate conditions, weeds overtaking, pest destruction, wrong breed of crop for conditions, soil/hydroponic management, etc. For 500 sq ft to be viable for 4 people, it needs to be taken care of in a very regiment fashion.
Not saying it's impossible. But that number shouldn't be advised for beginner homesteaders or people with less than ideal time to spend on the garden. It's great if at least one person out of four can devote a good amount of their time everyday to it and are already well experienced (hands on experience, not just internet articles) in horticulture.
Plus, you generally want plenty extra to harvest so you can jar, can, preserve however you want. That way in case you do happen to have a bad next yield, you still have something. Don't forget about seed-saving too. Most plants you have to sacrifice from eating to some capacity so you can plant again next season. Let's not forget the compost pile too to help re-fertilize soil and some rest time for the soil if you can't properly maintain it.
Oh and back on climate. Here in Florida, yea, I could probably figure it out with 500 sq ft. I have like a 10 month growing season here. Easy. Throw up a greenhouse with a heater that only needs to be ran maybe 10 days out of the year, at most, then I have 12 months. I can compost small piles fast all year round. It's near perfect here. Michigan? Ha! I know there are certain types of greenhouse designs that extend the growing seasons in places like Alaska to a certain extent and somewhat efficiently. But that's a lot more effort and work that most people aren't willing to do.
Long way of me just saying, that 500 sq ft for 4 people year round needs a heavy asterisk of "Under ideal and perfect conditions".
But my rant also requires an asterisk. I'm not saying that if you can't grow all your food, then don't grow anything. I think everyone should grow at least some of their own food in a manner that fits their wants, conditions and lifestyle. Just... have realistic expectations. I hate to see people have unrealistic expectations with gardening and be disappointed. Misses the point to the whole venture. There are downsides too. As a kid we grew our own tomatoes for fun. Nothing serious or wide scale. Like 10 plants a year. Problem with that (besides caterpillars), I absolutely hate most store bought tomatoes, even 20 years later. I have to have organic farmer's market grown or my own. Anything conventional store bought is just red-dyed, solidified water.
The USDA recommendation is just to provide the small amount of vegetables a family normally eats, not to provide all their calories. 50 sq m is absolutely tiny, and even with the most calorically dense crops like a 300 bushel/acre corn crop, that 50 sq m is producing less than 1000 calories a day, it won't support anyone.
I actually mean square meter. If you can feed yourself on 50 m² of conventional gardening, fine, go ahead. Not my experience. Put up a blog, don't buy any food anywhere else, post your body weight on a daily basis.
But the OPs question was about balcony / window shelf gardening anyway. I don't think a lot of people living within cities have a >50 m² balcony.
I think you are talking about two different things. He said "With intensive farming one would need around 200 - 500 m² to produce the calories required." You seem to be talking about producing some vegetables and still getting the bulk of your calories from the store.
I had a small 'jungle' on a balcony less than 3m2.
- Learn the hardiness of your area. This will tell what type of vegetables you can grow.
- Check how many _direct_ sunlight hours your balcony gets every day.
- Choose the vegetables you want to plant based on the two points above (hardiness and sunlight hours). Example: if you have lots of sunlight plant full size tomatoes. If you have less than ideal sunlight exposure plant cherry tomatoes.
- Learn what you can plant in each season and when to fertilize. Liquid fertilizer is your best bet in a small apartment.
- In a balcony on a tall building, wind is the enemy.
- If you get many hours of direct sunlight (6+) and your balcony faces south you can grow almost anything there.
- Prefer a few big pots to many small ones: A few big pots means less variety but will require less maintenance, watering and the plants will be stronger because their pot is bigger. I have 70L pots and they're great. I would bother with less than 20L.
- Some fruit plants will take more than 10 years to give you fruit and others can't self-pollinate. Avoid those at least when starting out. Radish grows in less than 30 days.
- I've successfully planted and harvested Raspberries, cherry tomatoes, broccoli, peppers, strawberries, carrots, parsley, radish and basil in a small balcony that isn't even south facing in Lisbon. It never produced enough calories but it was fun and the produce was very tasting. I tried to plant cantaloupe twice but it failed mostly because of the wind (I think).
- I prefer store bought soil with added perlite and textile pots. Perliet and textile pots improve root health in small pots.
I have an entire apartment floor but with small balconies so not much sunlight. Did you catalog your journey somewhere? I'd like to grow beets carrot and tomato (cabbage bonus)
Planting is very easy. Bury some seeds in the soil (not very deep) add water and if the temperature is right a plant will grow :)
The biggest mistake beginners do is too much water/to frequent waterings. When pests/disease appear ask in reddit until you start identifying the problems yourself but if a plant has enough sun, water and soil (don't overcrowd a small pot) and the temperature is correct for it to grow don't expect many problems.
If you don't have enough sunlight for fruits you can start with herbs like basil, parsley and coriander. Cherry tomatoes will probably also work but don't expect a huge harvest without appropriate sunlight. Carrots are a tiny bit harder to grow but I got a few to grow in a pot near a window so it's not impossible but they do like a lot of fertilizer.
I tried to grow round carrots in a plastic container on the balcony, with the idea that round carrots wouldn't need as much soil depth as pointy ones. But one day the green parts above ground was completely covered in some white web, so I gave up on them.
I still like the idea of round carrots, so I may have to try again some day. I don't think I've seen them in the supermarket.
I've been researching about this since I moved to a more urban area. I think the best bet is hydroponics in terms of cost and logistics. I know some people have a hybrid indoor/outdoor solution using the IKEA stuff[1]. The biggest problem with soil is bugs. I've had problems even with miracle grow bags. The only way to prevent this is to let the soil dry up in the sun for a day or two but it's very difficult for a small apartment balcony.
Its important to think in multiple layers: For example carrots and salad on the ground, tomatoes on top and way above beans.
One thing I would always recommend: potatoes - one of the most robust crops, that almost always work out.
For a balcony, the fun and the created atmosphere should play a role alongside the yield. You won't match your need for calories anyway...
Can you elaborate or link to a picture, please? What you're saying does sound interesting and I would love to have tomatoes too, besides beets and carrot. But I'm not sure how I would do it.
To give you an idea of what I have at my disposal- 3 balconies (except east), all small, 2ft by 20ft. All have iron railings which could come handy for the right type of veggie I guess. ..
I recommend an iterative approach: Plan -> Do -> Evaluate -> Change plan accordingly -> Do...
With limited space you will not have a high yield so planting potatoes etc. will not be that "profitable".
If you like to use herbs for cooking it can be a delight to grow your own.
Maybe you don't cook at all and think about plants which are expensive to buy so you can sell them as a side business.
So to maximize the return on invest you probably want to choose plants that:
1) don't need much space
2) survive the conditions at the location (try several plants and strains and only keep the survivors)
3) have a high-yield and are not consumed that often or in huge amounts (e.g. very hot peppers)
The soil you need and the ability to survive the conditions depends on the plants and their strains. I had some bad experience with "normal" basil and it would die very quickly but then I found some African Basil which has very fleshy leaves and strong trunks it would survive for years without changing the soil.
Some plants can survive more easily when combined with others. Philodendron[0] does not need or want full exposure to sun so putting some peppers in front of it increased it's life-time considerably.
You may want to do some research on the frequency of watering depending on the kind of plants you grow but also look for the condition of the plants while applying a certain amount of water, sun, fertilizer etc.
They won't die instantly if you water them too much or less but you will recognize that their growth rate is inhibited or the leaves and fruits don't get the "right" color or size. You will have to look for these indicators and experiment a little bit until you know the conditions of your place and the needs of your plants and therefor have more success with your growing efforts.
You can take the soil from pretty much everywhere but of course you should not take it from near some factory that may have contaminated it. Just think about the kind of plant and what it's natural soil would be like. Aloe prefer soil with some amount of sand while Philodendron maybe don't like that much of sand.
The soil from a river bed is probably a good choice for Mint, Philodendron etc. but not for Aloe (I assume it may not be dry enough for their taste).
I wish you all the best and hope you can use some of my advice. Happy planting :)
Thank you for taking the time to write a detailed response! Some of what you've written has indeed been helpful in corroborating a few of my learnings, and some new- eg. Soil type requirement is plant dependant and not universal.
While I was hoping for a very general and very quick guide for people to just dip their toes and figure out the rest as one goes, my specific intention is to grow carrots, beets, tomatoes and maybe cabbage.
With today's pollution this is no longer healthy. Fruits will absorb pollutants and the acid rains will stick to their skin slowly penetrate as well. That's why we have currently trees that are very resilient against cities harsh conditions, like Linden Birch Beech and Poplar (Populus).
Where is this coming from? There are certainly things you can do to grow fruit in the city or at least reduce the effect pollutants have. I've seen so many figs that thrive in cities.
We live in a steep sided river valley in northern Portugal, and the place came with 5 Ha of woodland, on a SE facing slope.
We’ve only lived here some six months, and we’ve gradually realised that almost every square inch of the hillside has been terraced - the process is to build hefty walls along the contours, and then let the hill slump into the gap, making a level growing area.
The thought that occurred to me/thing I noticed was just how much IR the wall I was working next to was emitting after the sun went down - felt like a patio heater pointed towards my face from a few meters away. I then realised that the reason that they’re all so incredibly overgrown is likely the combination of thermal mass warming the surrounding area, water being forced to ground level at the foot of each wall, and accumulated mulch being trapped by each wall.
I can’t count the number of times since starting here that I’ve marvelled at the simple ingenuity applied towards working with nature, from the terraces creating a better growing environment than the now-farmed planes above us, to the positioning and orientation of the mill - it’s situated at the one point along the bank that gets sunlight all day, all year, apart from two weeks in midwinter - which just happens to coincide with an outcrop that they co-opted into a weir.
Anyway. I wonder to what extent the idea of a fruit wall stemmed from people seeing this sort of terracing, and deciding to do it without a hill.
0: https://en.wikipedia.org/wiki/Permaculture
So while a walled garden has something of a negative connotation in technology, in horticulture it seems much more positive. Interestingly, looking at the definition of walled garden on wikipedia "A walled garden is a garden enclosed by high walls for horticultural rather than security purposes"[1] (emphasis mine).
[0] https://en.wikipedia.org/wiki/Law_of_the_wall
[1] https://en.wikipedia.org/wiki/Walled_garden
It says:
"Another issue with a solar powered greenhouse is the lack of a CO2-source. In modern greenhouses, operators aim to have a CO2-level at least three times the level outdoors to increase crop yield. This CO2 is produced as a byproduct of the fossil fuel based heating systems inside the greenhouses. However, when no fossil fuels are used, another source of CO2 has to be found. This is not only an issue for solar greenhouses. It’s also one of the main reasons why geothermal energy and electric heat pumps are not advancing in the modern glasshouse industry."
But do not forget that,at that time, Parisian did not often eat peach or raisin.
I am quite sceptical that indoor farming or other (re)new trendy technique could ever produce mass market fruit we are used to have.
A bit from 2015: https://news.ycombinator.com/item?id=10788619
https://solar.lowtechmagazine.com/2018/09/how-to-build-a-low...
Last year I had 6 plants grow perfectly happy outdoors, and these were from seeds of plants bred indoors for probably generations. The last plant was ready in freaking November.
Some of them cross pollinated (yeah, if you buy "feminised", that's not a guarantee lol), and now I have a few hundred new seeds that I plan on growing outdoors come May. Should be fun.
On that note, everyone around here has a small garden, mostly staple vegetables and fruits. But the soil is perfect for anything. And yet I see people growing stuff in controlled greenhouses even in the summer. Wasteful, if you ask me.
https://www.google.com/maps/@52.4618655,4.6455238,3a,48.9y,1...
The fruit trees are long gone but the wall still stands.
Until a few weeks ago there was an old pear tree trained against one wall - presumably to take advantage of the effect.
Also, notice how the walls are not in a grid formation. Maybe I missed that when skimming through, but I imagine that's for a reason?
Neat!
https://solar.lowtechmagazine.com/power.html
8 months ago: https://news.ycombinator.com/item?id=20038619
11 months ago: https://news.ycombinator.com/item?id=19407847
2018: https://news.ycombinator.com/item?id=18075143
https://solar.lowtechmagazine.com/about.html
1) sunlight requirements, different for plants
2) soil and replacement.
3) water, frequency and outlet.
What are some other things to care about? Where do I get soil? Is it okay to dig from an existing farmland? I live quarter mile from a river. Should I collect from river bank?
So with balcony farming I'd recommend focussing on greens that make your meals better. Microgreens are easy to do and add a lot of flavor to your salads and meals. For the rest herbs and leafy greens are the way to go. Herbs as perennials can be grown in soil pots. The plants in pots you can get in the supermarket usually do not last long. They are produced for maximum harvest yield at market time and usually have a hard time when trying to keep them. Get some heirloom seeds or cuttings and make soil from coco coir and perlite. For leafy greens hydroponics can make sense. Jeb the gardener on YT is funny and informative. It is easier to automate hydroponics than soil culture. Chili Chump on YT has a good series on that.
Consider running a bokashi indoor compost. The liquid collected from that is excellent organic fertilizer for the coco coir and the hydroponics.
Start small. Scale up as you gain more experience. Microgreens have a 10 - 14 day culture, so starting with those will give you a fast turnover and quick iterations for improvement. Try to purchase seeds in bulk, otherwise cost will be prohibitive. Organic seeds for commercial growers come in larger quantities at a reasonable price. Try to source those.
Most important of all: Have fun!
edit: fixed typo.
Me and my wife have grown stuff on the balcony, but the main reason that we don't anymore is that we go away for four weeks during the summer where there is the most need to water. We can grow things in the spring and in the autumn, but we miss the warmest period in the middle.
We bought four large clear plastic containers from IKEA that are intended to store stuff under the bed, drilled holes in the bottom of two of them for drainage, and put them in the other containers. We filled them with LECA pebbles and dirt, and watered with large PET bottles. It was all very easy.
One summer we grew kale in one container, but were discouraged when we harvested it and only had enough for one pie. Your first sentence triggered this memory, which is the point of my comment. Growing kale on that small scale was terribly inefficient, and the amount of work to water it far surpassed the joy of eating the pie.
Another summer we had curled leaf lettuce that was much better than kale. It grew so quickly that we could continuously harvest it and still have more growing. Of course you can't eat it for the calories, so it's just for fun.
We've also had windowboxes on the inside of the balcony railing with flavorful sallads and herbs, like rocket sallad, basil, chives, and so on. As you say, those add a lot to a meal without taking up too much space, and are easy to start with.
Less than 50 sq m (approx 500 sq ft) per person using conventional row gardening would be the norm - and with intensive gardening, that same plot could support a 4-person family.
Not saying it's impossible. But that number shouldn't be advised for beginner homesteaders or people with less than ideal time to spend on the garden. It's great if at least one person out of four can devote a good amount of their time everyday to it and are already well experienced (hands on experience, not just internet articles) in horticulture.
Plus, you generally want plenty extra to harvest so you can jar, can, preserve however you want. That way in case you do happen to have a bad next yield, you still have something. Don't forget about seed-saving too. Most plants you have to sacrifice from eating to some capacity so you can plant again next season. Let's not forget the compost pile too to help re-fertilize soil and some rest time for the soil if you can't properly maintain it.
Oh and back on climate. Here in Florida, yea, I could probably figure it out with 500 sq ft. I have like a 10 month growing season here. Easy. Throw up a greenhouse with a heater that only needs to be ran maybe 10 days out of the year, at most, then I have 12 months. I can compost small piles fast all year round. It's near perfect here. Michigan? Ha! I know there are certain types of greenhouse designs that extend the growing seasons in places like Alaska to a certain extent and somewhat efficiently. But that's a lot more effort and work that most people aren't willing to do.
Long way of me just saying, that 500 sq ft for 4 people year round needs a heavy asterisk of "Under ideal and perfect conditions".
But my rant also requires an asterisk. I'm not saying that if you can't grow all your food, then don't grow anything. I think everyone should grow at least some of their own food in a manner that fits their wants, conditions and lifestyle. Just... have realistic expectations. I hate to see people have unrealistic expectations with gardening and be disappointed. Misses the point to the whole venture. There are downsides too. As a kid we grew our own tomatoes for fun. Nothing serious or wide scale. Like 10 plants a year. Problem with that (besides caterpillars), I absolutely hate most store bought tomatoes, even 20 years later. I have to have organic farmer's market grown or my own. Anything conventional store bought is just red-dyed, solidified water.
As it stands US Department of Agriculture says that 120 sq m is enough for a family of 3 - thats using conventional gardening techniques.
But the OPs question was about balcony / window shelf gardening anyway. I don't think a lot of people living within cities have a >50 m² balcony.
- Learn the hardiness of your area. This will tell what type of vegetables you can grow.
- Check how many _direct_ sunlight hours your balcony gets every day.
- Choose the vegetables you want to plant based on the two points above (hardiness and sunlight hours). Example: if you have lots of sunlight plant full size tomatoes. If you have less than ideal sunlight exposure plant cherry tomatoes.
- Learn what you can plant in each season and when to fertilize. Liquid fertilizer is your best bet in a small apartment.
- In a balcony on a tall building, wind is the enemy.
- If you get many hours of direct sunlight (6+) and your balcony faces south you can grow almost anything there.
- Prefer a few big pots to many small ones: A few big pots means less variety but will require less maintenance, watering and the plants will be stronger because their pot is bigger. I have 70L pots and they're great. I would bother with less than 20L.
- Some fruit plants will take more than 10 years to give you fruit and others can't self-pollinate. Avoid those at least when starting out. Radish grows in less than 30 days.
- I've successfully planted and harvested Raspberries, cherry tomatoes, broccoli, peppers, strawberries, carrots, parsley, radish and basil in a small balcony that isn't even south facing in Lisbon. It never produced enough calories but it was fun and the produce was very tasting. I tried to plant cantaloupe twice but it failed mostly because of the wind (I think).
- I prefer store bought soil with added perlite and textile pots. Perliet and textile pots improve root health in small pots.
The biggest mistake beginners do is too much water/to frequent waterings. When pests/disease appear ask in reddit until you start identifying the problems yourself but if a plant has enough sun, water and soil (don't overcrowd a small pot) and the temperature is correct for it to grow don't expect many problems.
If you don't have enough sunlight for fruits you can start with herbs like basil, parsley and coriander. Cherry tomatoes will probably also work but don't expect a huge harvest without appropriate sunlight. Carrots are a tiny bit harder to grow but I got a few to grow in a pot near a window so it's not impossible but they do like a lot of fertilizer.
I still like the idea of round carrots, so I may have to try again some day. I don't think I've seen them in the supermarket.
https://www.ufseeds.com/product/parisian-carrot-seeds/
What type of fertilizer do you use for carrots? The regular indoor flower variety or something special?
[1] https://www.ikea.com/gb/en/cat/hydrophonics-pp002/
To give you an idea of what I have at my disposal- 3 balconies (except east), all small, 2ft by 20ft. All have iron railings which could come handy for the right type of veggie I guess. ..
With limited space you will not have a high yield so planting potatoes etc. will not be that "profitable".
If you like to use herbs for cooking it can be a delight to grow your own.
Maybe you don't cook at all and think about plants which are expensive to buy so you can sell them as a side business.
So to maximize the return on invest you probably want to choose plants that:
1) don't need much space
2) survive the conditions at the location (try several plants and strains and only keep the survivors)
3) have a high-yield and are not consumed that often or in huge amounts (e.g. very hot peppers)
The soil you need and the ability to survive the conditions depends on the plants and their strains. I had some bad experience with "normal" basil and it would die very quickly but then I found some African Basil which has very fleshy leaves and strong trunks it would survive for years without changing the soil.
Some plants can survive more easily when combined with others. Philodendron[0] does not need or want full exposure to sun so putting some peppers in front of it increased it's life-time considerably.
You may want to do some research on the frequency of watering depending on the kind of plants you grow but also look for the condition of the plants while applying a certain amount of water, sun, fertilizer etc.
They won't die instantly if you water them too much or less but you will recognize that their growth rate is inhibited or the leaves and fruits don't get the "right" color or size. You will have to look for these indicators and experiment a little bit until you know the conditions of your place and the needs of your plants and therefor have more success with your growing efforts.
You can take the soil from pretty much everywhere but of course you should not take it from near some factory that may have contaminated it. Just think about the kind of plant and what it's natural soil would be like. Aloe prefer soil with some amount of sand while Philodendron maybe don't like that much of sand.
The soil from a river bed is probably a good choice for Mint, Philodendron etc. but not for Aloe (I assume it may not be dry enough for their taste).
I wish you all the best and hope you can use some of my advice. Happy planting :)
[0]: https://en.wikipedia.org/wiki/Philodendron
While I was hoping for a very general and very quick guide for people to just dip their toes and figure out the rest as one goes, my specific intention is to grow carrots, beets, tomatoes and maybe cabbage.
You are basically stealing sunlight from x% of the land to somewhat improve the 1-x%
The in-efficiencies of the past are quite beautiful.
i.e. https://academic.oup.com/bioscience/article/67/9/868/4080176
Check out permaculture, it's entirely possible.