Introduction: Urban Farming: Raised Bed Gardening
To optimize limited space in our backyard, we make use of raised beds for growing vegetables. After several years, we are finally reaching a point of continual success with our backyard urban garden. I put together this instructable to help anyone else thinking of gardening in raised beds or having limited success. Raised beds have the benefit of organizing and easily dividing your gardening space. You can work on one bed at a time and have a sense of accomplishment if you don't have enough time on your hands to do all of them. We place wood chip mulch in between the beds for dirt-free walking paths. Depending on the type of raised beds, they can also be made higher. For some people, like me, this makes taking care of your raised beds a little easier since you don't need to kneel down as much. There are several factors that are important for success with raised beds: soil, watering, plants, and pest control.
- DIY: I'm into DIY, so initially, I made my own. I used 2 x 6" redwood boards and found that good quality redwood is quite expensive. If you make your own, make sure to stay away from pressure-treated lumber. It will last longer, but it will also leach dangerous chemicals into your soils. Natural Cedar, Redwood or Pine all work well.
- Ready-made: When I priced out the lumber and time it would take to buy and make them, it was more cost-effective to buy them ready-made. I am a big fan of DIY, but when ready-made gives you better quality for less price, I will save my time for other projects. We looked through all of our neighborhood home improvement stores and perused multiple gardening catalogues. We knew that we wanted a natural wood like Cedar or Redwood. We did not want to use any plastic boards. We decided on using Cedarbrook. They primarily build Saunas and Steam rooms, and the wood for the raised beds is a recovery product for them. This means that the wood that wasn't good enough for the Sauna or Steam products is used for the raised beds. This was appealing since it it is sort of recycled and the prices are more reasonable. They carry multiple sizes and heights. Additionally, their beds come with a simple interlocking system with an aluminum rod for assembly which makes putting them together a snap. We purchased several beds of different sizes and heights to add variety in the garden. We have four beds at 22" height (4' x 8', 3' x 8' and 3' x 6'), 1 bed at 16.5" height (3' x 4'), and 4 beds at 11" height (3' x 6' and 3' x 8'). I enjoy using them and like having the height difference. It adds a little more variety into the garden. In total, we have 180 square feet of gardening space in our raised beds. One thing to keep in mind with taller beds is that you will need much more soil to fill them.
- One of the benefits of raised beds is you can control the soil going in. For our raised beds, we trucked in a good quality soil to fill the beds with. Good soil will have a proper mix of soil and organic material. This means that over time, the organic material will decay or be eaten by bugs like earthworms and your soil level will slowly sink. Over the course of a year, our beds will sink by 1-2". We add compost with each new planting to bring the level back up to the top.
- Irrigation: It is difficult to find time to get out and water every day, so a programmable drip irrigation system is very helpful. This helps to save not only time, but water. We installed a drip system in each of our beds. We installed the white irrigation pipes into the top of each bed. Then we made a 3-row drip irrigation tubing set-up in each bed. These are held in place with metal stakes. The second photo shows how the drip irrigation is set-up in the bed. Our irrigation is set-up to run for 10 minutes in the morning.
- Hand watering: When you are starting from seeds or small starter plants, you may need to hand water the soil to keep it moist. Drip systems are excellent for established plants, but they don't get to every corner or top of all the soil. For starters or seeds with small roots, it is very important that you don't let the soil dry out.
- We save the cold water from our showers for watering in the yard. Instead of installing an expensive return system, we collect the cold water into a 5 gallon bucket. It gets full every two days and gives us extra exercise and cuts down on our water usage.
- What to plant: If you live on the West Coast of the US, the New Western Garden Book by Sunset is a must have. They do a great job explaining the different climates and microclimates and what works best for your area. For instance, we live in the foggy area of San Francisco. We don't have much success with tomatoes or cucumbers, but we can grow lettuce, arugula, kale, radish like nobody's business. However, just 20 minutes away, the situation can be reversed. Paying attention to your micro-climate and what will thrive in your area and you will have greater success. It's not a question of having a green thumb, but what will grow best in your yard.
- Seedlings: Planting your own or buying them from a nursery gives you a head start in the raised bed. Acclimate them in your yard for a day or two before transplanting. When I buy starter plants, I save the 6-pack containers for planting my own starts. Do not start any root vegetables in starter containers. They don't transplant well and should be started from seed in the raised bed.
- Seeds: We have moved completely over to organic, non-GMO, heirloom seeds. Locally, we are fortunate to have a store called the Seed Bank that carries Baker Creek. I have had very good success with their seeds as well as Botanical Interests.
- How to plant: Our vegetables are planted in rows within the beds. In the 3 foot wide beds, we plant three rows. The middle row is usually for taller plants like Kale, Collard Greens, Chard, Green Onions, Tomatoes, Peas, Beans. On the outside rows, we plant shorter plants like lettuce, carrots, radish. For some plants like lettuce and radish, you don't want to plant too much at once since it will all mature at the same time. You can make successive plantings so they are offset in maturing and you won't have too much on hand all at once. Follow the instructions on the seed packet for planting instructions. For depth, a general rule of thumb is twice the thickness of the seed. Lettuce and Carrot are barely covered, wheres bid seeds like peas and beans are planted 1/2" - 1" deep.
- Supports: Some vegetables will need supports. Tomatoes will do better when they have a stake or cage to help hold them up. Cages are available for a few dollars at any nursery. Peas and Beans do well with netting, string or trellis support. You can use gardening twine to loosely secure them to the supports until their tendrils take over.
- We apply an organic vegetable fertilizer from E.B. Stone. We will mix some into the soil during initial planting. Then, I will gauge the plants growth for the next application. Some plants will grow more rigorously than others and will need more fertilizing. I think of it as when they grow quickly, they are using up the nutrients in the soil. Fertilizing is helping to replace these nutrients. Follow the instructions for fertilizing. Too much fertilizer will burn up your plants. Don't love your plants to death by giving them too much of a good thing.
- Snails and slugs: These bugs can wreck havoc on your vegetable garden. We have had days where dozens of seedlings sprouted only to find them mowed down the next morning. These slow moving bugs can do a lot of damage at night. We tried going out at night to catch them, but you can only catch a few. We've tried copper tape around our beds. This is good at not letting any new ones in, but you have to make sure all of the ones in the raised bed are killed. I tried a beer trip with no success. The best solution so far has been the use of Sluggo. There is a regular and organic version. Both work well and are safe for application up to the day of harvest.
- Moles/Gophers: We had a gopher take up residence in our backyard last year. We would find mounds of dirt, holes all over and a bunch of missing plants. It got so bold that it no longer ran away when we were around. My wife even had a video of it eating one of our plants, cartoon style. A gopher trap was the only thing that worked to get this pest. If your area is known to have moles or gophers, you may want to consider installing hardware cloth along the bottom of your raised bed.
- Birds: Small birds can also cause a lot of damage to young plants. This has been a minor problem for us. Hanging tinsel on posts or branches can help deter them from your plants.
- Harvesting plants at the right time is sort of like selling stocks. If you wait too long, things go downhill most of the time. When your plants are ready, they should be pulled and eaten. With the leafy green vegetables like Lettuce and Kale, you can remove some of the outer leaves and let the plant continue growing. If you take a few leaves from each plant each time, you can extend your harvest and double or triple the amount of leaves each plant produces.
- Cleaning: I keep a bucket of water in the yard for cleaning the dirt off the roots. The water will go back to watering plants, while the sediment is put into our compost.
- For gardening, I have found the following tools to work best.
- Hori Hori Tool: By far, this is my favorite gardening tool. It sort of looks like a survival knife I had when I was a teenager. It has a sharp tip for digging. It is slightly concave, making a very shallow, semi-functional scooper. It has a serrated edge which is extremely useful for cutting through root balls. I purchased the stainless steel version from Amazon. It is kept outside and is still shiny and functional like the day we bought it.
- Scissors: Good for cutting off leaves
- Pruning Shears: Good for cutting thicker stems
- Scoop/shovel: For moving dirt around
- Watering Can/Hose
- I have built and tried a three-stage composter. It didn't work well for me. Primarily because I wasn't constantly in the yard and adding to it and tending it. I have periods where I am in the yard every day, but then weeks where I can't put significant time in the garden. I have now moved to one of those spinning composters. It works pretty well for us. It takes up less space and works for the amount of material our backyard generates. I put in some dirt to start it and then add yard clippings and shavings/manure from our chickens. I will cut stems and really fibrous material down to about an inch long before adding into the composter. Regardless of your composter, the primary factor will be time. I will get about 3 batches completed every year.