If your current planting goals involve plants that require good water drainage or retention, I am sure you know how frustrating it is to have a yard that just won’t cooperate. Some plants can handle the excess water that comes about from being in an area that doesn’t drain properly. In fact, it might just cause them to bloom more lushly. However, other plants don’t cope as well, and it will cause them to die a gruesome, bloated death. You should always find out about the drainage required for every plant you buy, and make sure that it won’t conflict with any of the areas you are considering planting it in.
The opposite of this is also true. If you live in an area that is dry and the soil is not as productive, a raised bed will also work. I live in an area where the soil is alkaline with clay and the soil has a hard time retaining moisture. You can add lots of organic matter like peat, compost, and manure to the entire garden or build raised beds and build the soil in the bed. This works great but you may need to water more often and mulch the boxes. Not only is rain on short demand but the air is dry.
In order to test how much water your designated patch of soil will retain, dig a hole approximately ten inches deep. Fill it with water, and come back in a day when all the water had disappeared. Fill it back up again. If the second hole full of water isn’t gone in 10 hours, your soil has a low saturation point. This means that when water soaks into it, it will stick around for a long time before dissipating. This is unacceptable for almost any plant, and you are going to have to do something to remedy it if you want your plants to survive.
On the other hand if the soil drys quickly and does not retain water you will need to add amendments to the soil to offset this. You can either build the soil in the entire garden or just in the box. This way you can control the properties of the box to better suit the plants. I have done both and there are pros and cons in either situation. When you adjust the soil in the entire garden it will retain water better and does not need to be watered as often. The only problem is the cost. Building your box costs less but needs to be watered more often. A side benefit to the box is weeds and pests are easier to control.
The usual method for improving drainage in your garden is to create a raised bed. This involves creating a border for a small bed, and adding enough soil and compost to it to raise it above the rest of the yard by at least 6 inches. Youll be amazed at how much your water drainage and or retention will be improved by this small modification. If youre planning to build a raised bed, your prospective area is either on grass or on dirt. For each of these situations, you should build it slightly differently.
If you want to start a raised garden in a non grassy area, you won’t have much trouble. Just find some sort of border to retain the dirt you will be adding. I’ve found that two by fours work very well. The main problem is that 2x4’s are heavy if you need to tier them high and they are a bitch to move if the need arises. I like redwood or cedar fencing planks that are up to four inches wide. They are easy to move and to add addition height. Raised beds tend to keep getting taller and taller. In fact, you can build a raised bed from any kind of available material you have on hand; cinder blocks, wood, even straw bales. You are only limited by your imagination and material available.
2X4 Raised Bed
After you’ve created the box, you put in the proper amount of soil, compost, peat moss and manure. You need to get the composition of the box just right. If you add too much soil and not enough organic material the box will compact and lose it’s productivity. Depending on how long you plan to wait before planting, you will want to adjust the ratio to allow for any deterioration that may occur. Remember the soil and air are in balance, things come down from the air and the soil returns the favor.
2X6 Raised Bed
If you’re trying to install a raised bed where sod already exists, you will have a slightly more difficult time. You will need to cut the sod around the perimeter of the garden, and flip it over. This may sound simple, but you will need something with a very sharp edge to slice the edges of the sod and get under it. Once you have turned it all upside down, it is best to add a layer of straw to discourage the grass from growing back up. After the layer of straw, simply add all the soil, organic material, and manure that a normal garden would need. Remember the more you add to the box the taller it needs to be. The plant needs enough space for roots to develop. Plants may need 6-8 inches of soil for proper development. Another way is to cover the grass with a layer of card board and this keeps the grass from returning and will decompose over time. I like to plan ahead where I have plenty of extra time and I cover the selected area with a plastic tarp and let the grass die from lack of sun light. This also work if you have a large grassy area you need to prep.
Cedar (31/2 inch) Raised Bed
Planting your plants in your new area shouldn’t pose much difficulty. It is essentially the same process as your usual planting practices. Just be sure that the roots dont extent too far into the original ground level. The whole point of creating the raised bed is to keep the roots out of the soil which saturates easily. Having long roots that extend that far completely destroys the point.
But if the soil is well drained and dry this will keeps the soil under the box free from drying. Your plants can them extend the roots as deep into the ground as necessary. This way you can keep the height of the box from becoming a sky scrapper. Check your building codes.
Once you have plants in your new bed, youll notice an almost immediate improvement. The added soil facilitates better root development. At the same time, evaporation and decomposition are limited, you do need some decomposition that’s where the nutrients come from. All of these things added together makes for an ideal environment for almost any plant to grow in. So don’t be intimidated by the thought of adjusting the very topography of your yard. It is a simple process as Im sure you’ve realized, and the long term results are worth every bit of work. Just check the box frequently to keep it from drying out, having the soil above the ground level can facilitate the need for more frequent watering.
There are many books and articles about raised bed so do some research and get your hands dirty!