- Author: Amy Breschini
UC Master Gardeners for their monthly
"Advice to Grow By" Workshops!
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Learn how to Build Raised Beds!
Click HERE to find a great step-by-step instructions by Sunset on building your own raised bed!
The Benefits of Raised Beds
- They warm up and dry out faster in spring, so plants get a jump-start on the season.
- You can grow more vegetables in less space and have less area devoted to paths.
- They create attractive, well-organized planting areas.
- They save on the amount of fertilizer and compost used because it's concentrated just on the planting beds.
- It's less work, especially if you make permanent raised beds bordered with wood, bricks, or stone. You won't have to remake the beds each spring.
- The plants will have healthy root systems because you won't be stepping on the planting bed, compacting the soil, and making it hard for roots to grow.
- You can be more creative with design, making round raised beds for example, and planting vegetables, herbs, and flowers in various designs on the raised beds.
- It's easy to plant climbers such as cucumbers up an A-frame trellis because it fits nicely over a 4-foot bed.
- It's easy to fit season extenders such as row covers with wire hoops over the 4-foot beds.
- Raised beds are designed with the human back in mind – less bending and stooping over.
- Lower maintenance for weeds, watering, pests and replanting.
- You’ll have more control over your soil mixture and you can easily change the soil texture, fertility and tilth.
- Ability to add gopher wiring and copper barrier around edges easily.
- Raised beds are a good way of balancing nature’s resources.
- They're beautiful!
Key points - good drainage for proper aeration and organic matter, organic matter, organic matter!
- Decide whether to use an amended garden soil and organic matter or a growing media like potting soil with amendments.
- Mix the top several inches of native soil with several inches of whatever you put in the raised bed to prevent abrupt soil boundaries that could impede drainage.
- Put down hardware cloth to eliminate gophers.
- Very sandy soils or soils high in clay will have the most benefit from organic matter amendment.
- If you use garden soil, double dig the planting bed to make sure that amendments and organic matter are uniformly mixed.
- Aim for at least 4 to 5% organic matter to soil ratio, good compost works well (good compost doesn't look like the original materials, but has a dark rich appearance and a moist, crumbly texture.)
- Add 2 to 3 inches of compost for every 6 to 8 inches of depth and mix well. 3 cu. yds of compost covers 1000 sq ft 1 inch deep
- Check the pH in the root zone after a week or so - should be around 6 to 6.5. Lime or sulfur can be used to adjust pH up or down, respectively.
- Leave at least 2 inches for a mulch on top of the beds
Other issues to consider:
- Peat moss is often mentioned as an organic matter addition - is this a sustainable amendment?
- Manure also mentioned as an organic matter addition –it can add salts to the bed and should not touch the edible parts of the plants.
- Good quality compost (fully composted, no large pieces of woody material) is best and sustainable.
- Vermiculite and perlite are also referred to as good soil amendments- they can be costly for large beds but may be reasonable for smaller units. They are also very light and tend to rise to surface and wash away.
More information can be found here:
Soil Information for Raised Beds:
Soils and Trouble Shooting:
Chemically Treated Lumber Info:
Vegetable Gardening Basics:
Master Gardener Gardening Resources: http://camastergardeners.ucdavis.edu/files/64772.pdf
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