How to Grow Vegetables in a Small Space

You don’t need a lot of space to have an abundant vegetable garden. Here’s a raised bed that’ll yield tons of fresh flowers, fruits and veggies in just a few square feet

It’s possible to grow an abundance of vegetables in just a few square feet of space

The “harvest” was a couple of bean pods and four beans total. Not much, but more than enough to get me hooked on gardening in small spaces.

Once I got older and had my own apartment, I experimented with different combinations of pots and planter boxes on a tiny balcony to grow tomatoes, beans, lettuce, flowers, and more, amazing both my (then future) wife and our neighbors with how much I was able to get in such a small space.

These days I have several thousand square feet of vegetable garden where I grow all kinds of things, but I still have a fondness for small gardens, and maintain a little garden up near the house, conveniently close to the kitchen.

It’s a raised bed squeezed into an 8-foot by 8-foot space, but it produces literally hundreds of pounds of fresh food year-round thanks to a clever design.

This little round garden is called a keyhole garden, and it’s designed to pack a whole lot of growing space into a very small area, while also being super easy to maintain. Better yet, unlike some raised beds, this one is a simple do it yourself project that costs very little to build.

The garden is called a “keyhole garden” because in the center of the raised bed there’s a small compost bin into which you throw kitchen and vegetable scraps. Nature turns those scraps into nutrients that leach back into the bed and feed the plants. In bigger versions (i.e., more than 6 feet across), there’s a notch cut in the garden to allow easy access to the compost bin, so it sort of looks like a “keyhole.”

How to build a keyhole garden for a small space

My keyhole garden fits in an 8 foot x 8 foot space

There’s no real trick to building the bed. You simply set up some circular walls, make a “bin” for the center out of wire mesh, and fill the bed with garden soil. The diameter of the bed can be as small as 45 inches or as large as 8 feet. The point is to be able to access any portion of the bed without having to stretch to reach it.

Very Small Space (4 feet and under)

For a bed in a really small space, you can use a hard plastic wading pool as the bed frame. They’re usually 45 – 48 inches in diameter and 12 – 18 inches deep, which is more than sufficient for lots of compact, container variety veggies and flowers.

A plastic wading pool makes a great small keyhole garden

There’s no need to cut out a “keyhole” notch in the side since the bin in the center will be within easy reach. But you do watch to drill plenty of holes in the bottom (or remove it entirely if you’re placing it on dirt rather than concrete) to ensure good drainage.

In order for nature to work its magic, the compost bin should be at least 12 inches wide to allow good air and water circulation. You can make one with a piece of wire mesh, or repurpose a small wire waste basket, which is easy enough to find at your favorite online or discount store.

Small to Medium Space (Larger than 4 feet)

If you’ve got a larger space, you can build your garden bed walls out of rock, bricks, wood, or something similar. It just needs to be able to hold the weight of the soil (I’ve seen one made from cut ABS pipe and pipe hanger straps that looked pretty cool).

My keyhole garden bed walls are made from cedar fence boards

You want your larger bed to be at least 18 – 24 inches deep, so that you can fill the bottom portion with biodegradable material like cardboard, sticks, leaves, grass cuttings, etc., and top it off with garden soil. As the material below breaks down, it not only provides better drainage, but it’ll also provide nutrients to the outer portions of the bed where it’s harder for the compost bin to reach (this is a form of organic “lasagna” gardening).

How to choose vegetables for small spaces

Because you’re working with a smaller garden, all of the things that affect a larger garden — location, environment, soil capacity, etc. — are concentrated, so you need to be more aware of them that you might otherwise be.

The first thing to be aware of with your small garden is its orientation and exposure.

Most veggies want 6 hours or more of sunlight a day. That can be complicated because smaller gardens are more often in areas surrounded by walls, fences, and other structures that can block the sun from reaching the plants, as well as provide protection from weather and radiate heat back into the garden.

If your garden is open all the way around, make note of how much sun it gets and for how long. If it’s shielded on one or more sides by walls, fences or hedges, make note of the direction(s) in which it’s shielded.

Gardens with an eastern or northern exposure will get more sun and warm up quickly in the morning and be cooler in the afternoon. Gardens with southern or western exposure will remain cooler in the early parts of the day, get the full measure of sun in the afternoon (when it’s strongest), and may continue to receive radiated heat from the fence/wall into the evening.

Knowing the exposure will help you select veggies and make smarter choices with companion plants that can provide shade, support, etc.

Veggie Selection

The good news is, there are more veggies than ever bred to grow in small spaces, especially if you’re starting from seed.

Generally, when you’re selecting your veggies for a small garden, you want to look for varieties that are described as being “compact”, “bush” and/or “container” in their growth habits. Unlike their field cousins which sprawl out, grow tall or occupy large areas, these smaller forms will allow you to pack more variety into your garden.

Better yet, unlike pots or planter box gardens, a small keyhole garden gives you more root space and a constant source of soil nutrients (via the compost bin), so you can plant larger (but still relatively compact) veggies such as bush zucchini, sweet corn, and tomatoes, and still enjoy a large harvest.

A keyhole garden’s nutrient density and easy access to all areas of the bed also allows you to plant more densely than you would in a container. I’ve found you can squeeze plants into about 2/3rds of the recommended space (for example, spacing plants 8 inches apart instead of 12 inches) and still have a healthy garden with a higher yield than you might otherwise.

You can pick up plants at your local nursery or garden center, but if you like growing from seed, I recommend Pinetree Garden Seeds, which sells small packets of seeds for a low price, so it’s perfect for the small gardener who likes to grow a variety of different veggies.

Here are the varieties I’ve grown in my keyhole garden and can recommend for small spaces:

Make use of companion planting

Additional considerations for the small vegetable garden are companion planting and crop rotation.

Smart companion planting (such as the “three sisters” method) will boost your yield because the crops benefit each other without competing for soil nutrients. In the case of the “three sisters”, you plant beans which pull nitrogen from the air into the soil; corn which uses the nitrogen to grow tall and leafy and becomes support for the bean’s runners; and squash which grows under the corn and provides shade and weed suppression.

A keyhole garden isn’t dependent on nitrogen from the beans (the compost bin does a good job of providing that), so you can also consider some other companion planting methods like the “Italian kitchen” – tomato, basil and cucumbers – that attracts beneficial insects, or the “high-low” where you plant a low-growing leafy crop such as lettuce or spinach followed by a taller crop like peppers, tomatoes, etc. The leafy stuff provides cover from the tall plants early on, and the tall plants provide cover for the low ones so they don’t bolt as quickly once the weather gets hot.

Extend Your Growing Season

One of the other great things about the small keyhole garden is that it’s possible to extend your growing season without a lot of effort.

As a raised bed, it will hold heat and provide better drainage than pots or planters. Moreover, the microbial activity in the compost bin will continue to radiate heat as well as nutrients into the bed even after it starts to get cold.

For regions where frost or hard freezes eventually bring the bed to a halt for the season (USDA zones 6 and lower), you can get an extra 2 to 4 weeks at the beginning, and an additional 4 to 6 weeks of growing at the end of the season– basically a whole extra crop of leafy greens or cold tolerant veggies like broccoli, cabbage and cauliflower.

If you’re in a warmer area (USDA zones 7 – 10), you can get two months or more of additional grow time. Here in Zone 9, my keyhole garden never stops growing at any point in the year!

Troubleshooting common problems

Too dry / Too hot

The biggest problems with vegetable gardens in small spaces are usually location or environment related. Too much sun and/or heat will dry the soil quickly so the plants will struggle to take up water. You can counter that by watering in the evening or early morning to ensure they’ve had plenty to drink before the sun hits its peak. During the heat of the day you can also provide some shade cover using cheap, plain old burlap or landscape cloth.

Poor drainage

If your soil stays wet even when it’s warm, it’ll impact the ability of your veggies to absorb the nitrogen and oxygen trapped in the airspaces in the soil, both of which are critical for plant growth.

For the small garden, soil that won’t dry is almost always an issue with poor drainage. Either the garden soil has too much clay, which prevents water from being absorbed, or the bed isn’t allowing water to escape.

The easiest way to improve clay-heavy soil is to toss organic materials such as dry leaves, decomposed straw and compost into the bed. This increases the airspace in the soil (air should be around 25% of your soil’s makeup), leaving more room for water to escape.

If your soil is good, then it’s probably your bed container. If you’re using plastic (like the kiddie pool mentioned above), or a non-porous material like rock or brick, you need to increase the drainage out the bottom by creating more holes in the bottom of the bed or breaking up the soil that’s under the raised bed.

Weak compost activity

If your compost bin doesn’t seem to be breaking down organic matter (vegetable scraps, eggshells, coffee grounds, plant cuttings, etc.), or it’s producing off smells (compost shouldn’t smell like a swamp), it’s either because it’s too dry or too wet.

Water is necessary for microbial activity, so you want to make sure the bin stays moist, but not so moist that it’s sloppy and wet. Usually your organic matter will provide moisture all on its own, but if it seems dry, add some water to it and stir it around to kick up the activity again.

If the compost is wet and gooey, help it out by adding dry, carbon-rich materials like newspaper, brown leaves, straw, and even torn up shreds of cardboard. Again, after adding these things, stir it around to kick up the microbial activity again.

Pests

Fortunately, insect pests, fungi, and other nasty critters aren’t usually a big problem in a small garden.

Crawly pests – Snails, slugs, caterpillars, and the like are pretty easy to spot and can quickly be removed by hand. Aphids are often a problem, but if the local predators like ladybugs, etc. don’t keep them in check, they can easily be neutralized with a little soap/oil spray.

Rolli-Pollis are not pests! They’re your friends in the garden!

Note: Rolli-pollis, sowbugs, pillbugs, etc. are not pests!

They’re an important part of the organic process, eating fresh dead matter and turning it into by-products smaller animals and microbes will convert into soil nutrients.

If you find these little guys in your garden, they’re helping by doing cleanup. If, on the rare occasion you find they’re eating living plants, it’s because you’re not providing enough fresh organic matter to your compost bin. They’re eating living plants as a last resort, so you need to add more stuff like vegetable and fruit cuttings, grass clippings, coffee grounds, banana peels, etc. to the compost bin. They’ll stop munching your plants immediately.

In addition the the common bug pests, once in a while you’ll also end up with pests of the feathered or furry kind.

Furry pests – Rodents can be a big issue for the small space garden. Mice, rats, rabbits, squirrels, and gophers may be little, but they can show up in droves and, given the opportunity, will eat everything to the ground (or, in the case of gophers, below it).

You can control these guys easily with nothing more than hot chili powder dissolved in water and sprayed on the plant’s leaves, stems and fruit. It has no effect on the plants, insects, reptiles or birds, but it’s a five alarm fire for any rodent who decides to try it. Applied every couple of weeks, rodents won’t touch your plants or vegetables.

Feathered pests – While some birds will figure out that your vegetables taste good (crows and their cousins – magpies and jays are notorious for this), most are there to help. They eat insects, pollinate the flowers, and add a little of their own “fertilizer” while doing it, so it’s nothing to worry about.

On the other hand, sometimes they can get to be a problem. Sometimes it’s because there’s a nest nearby (nothing like being dive-bombed by mockingbirds), sometimes there’s just too many (there’s nothing “charming” about a charm of finches marauding you flowering basil).

I’ve tried just about everything for bird control, and other than a real life Cooper’s Hawk, I haven’t found anything that’s 100% effective. Decoys like plastic owls, weird big-eyed balloons, and scarecrows work only for a short time before the birds figure the game out. Bird netting is a pain (though sometimes necessary when it’s a big bird) and gets tangled before falling apart.

The only cost effective (semi)effective bird repellent I’ve found is metallic strips.

Dollar store mylar flags do a good job at deterring birds

Most birds don’t like a lot of flashing or movement, so if you spend a few bucks at your local dollar-plus store, you can pick up a bunch of those cheap metallic party banners. String a few in the garden and they’ll keep most birds away because the erratic flashing and flapping makes them nervous.

Crows, not so much. They catch on pretty quick, so just cross your fingers and hope that if they show up, they’re dumb ones.

Make the most of your space and reap the rewards

Growing your own vegetables is a great way to keep food costs down and ensure you’re eating fresh. Better yet, you can grow an abundance of fresh vegetables in a very small space with very little money or effort by using the keyhole garden technique. It’s organic, self-sustaining, and so productive your gardening friends will be jealous.

Try it yourself!