Unless you are already endowed with good soil and a ready site, you will need to prepare your soil for planting. Preparation involves laying out your site, removing anything that has to go, making beds, and amending and grading your soil. Depending on your design and your site, this could be very easy work or long, involved work. Whatever the case, thorough preparation on your part will pay big rewards later. The following are some important details and hints to help you prepare your site.
First, a word of caution: As we mentioned in Module 1 Lesson 2, before you prepare your garden, be sure to check the depth of your soil. You don’t want to discover that there is bedrock 3 inches below the surface after you have stripped the grass from your future perennial bed!
Outline the bed using stakes, a hose, or powdered lime.
If the proposed bed is currently part of your lawn: cut out the bed with an edger or spade, being careful to cut a smooth line along your outline. Use a spade or sod cutter to remove the grass. Be sure to remove the grass roots below the surface but try not to remove too much soil. Shake the dirt from the grass into the bed, and dispose of the grass.
If you have another area in need of grass, you may want to consider transplanting the dislocated grass to the new area. If you do, don’t shake the dirt out of the roots (a sod cutter is best for this).
Note: A spade will be fine for a small bed. If you have to strip a large bed, you may want to rent a sod cutter. Sod cutters work by slicing an 18 inch wide strip about 2 inches deep so you can often roll the cut sod up like a carpet to haul away or reuse elsewhere on your property.
Your next step is to turn the soil in the bed, using either a tiller, shovel, spade, or spading fork. Try to work at least 8 inches of the soil, breaking up large clumps and removing any roots or rocks.
If the soil below the surface is compacted, you may want to try double digging to loosen it up. This is harder work, as you must turn the soil to about 20 inches deep. Still, in some cases you may find it very worthwhile.
Dig a trench down to the compacted hardpan (usually about six to twelve inches below the surface). It should be about two feet wide. Pile the excavated soil along the edge of the trench. Spread a layer of amendments along the bottom of the trench and turn the soil (do not mix this layer with the already excavated soil). Fill the trench with the topsoil you removed and repeat the process in the next row.
Now is the time to amend the soil. Evenly spread any fertilizers or amendments over the bed and turn the soil one more time. Then grade the bed with an iron rake, leveling and smoothing the soil.
If the bed is next to a building, smooth it out with a gentle slope away from the building to channel water away from the foundation. Take your time and try to get a good smooth grade—it will make a big difference in the quality of your installation.
If you are installing edging, in-ground sprinklers, drip irrigation, filter fabric, etc. you should do so now. You may have to re-grade after doing this.
Hint: When using an iron rake for grading, the rake should be held close to your body and at a steep angle (between 5 and 40 degrees). By holding it at such a steep angle you will have more control over it, which in turn allows you to get a more even grade. Try it—it may seem awkward at first, but you’ll soon see the results!
Woody Plant Preparation
If possible, dig a generous hole for the plant—about two times the width of the root ball or container but just as deep as the ball or container. Do not amend the planting soil or hole: research shows that doing so encourages the plant roots to stay in the hole rather than branch out. The plant becomes, in essence, a large potted plant. After planting, you can spread an inch or two of compost over the top of the entire planting area to amend the soil. If you will be planting a bunch of trees or shrubs in a large bed you can prepare the entire bed as discussed earlier.
Tip: When planting in your lawn, put the excavated soil into a wheelbarrow, tarp or piece of cardboard. This will make cleaning up easier.
For people growing vegetable gardens, preparation will be similar to garden bed preparation. When you create a vegetable garden consider a few things before you plant:
- Do you have full sun conditions (at least six hours of direct sunlight)? If not, you may want to grow leafy vegetables, which often fare better than other plants in shady conditions.
- Do you have enough room to plant what you want? A 10′ x 10′ plot will not yield a successful harvest of pumpkins, melons, cucumbers and corn.
- You can build up plant beds to help vegetables grow better. Mounds should be at least 5 inches high and 10 or more inches wide. Space these beds to provide walkways.
- Avoid using treated wood in vegetable gardens. The chemicals used to treat the wood can leach into the soil over time, and any chemicals in your soil are likely to end up on your dinner table.
- Use a filter fabric to cover the ground and keep weeds at bay. If you don’t like the appearance, put a layer of light mulch on top of the fabric.
- Plant the tallest plants on the north end of your garden and the shorter ones on the south end so that the short plants don’t get shaded by the taller ones.
Before resorting to installing drainage systems consider double digging if possible. Double digging is covered earlier in this module. In addition, many drainage problems can be solved, or at least diverted, by simply adding enough soil to help shed excess water to another area of your property. Just be certain you are not creating a new drainage problem for you or for someone else when you change the slope of your new garden beds.
These are a simple but effective way to improve drainage in areas where soggy soil is a problem, but puddles don’t stand for a long time. With an auger, post digger, or shovel dig a hole through the hard packed soil horizon. The hole needn’t be more than 3 feet deep, and can be anywhere from 8 inches to 2 feet wide.
You can use filter fabric sleeves and zip ties to create “socks” that you fill with washed ¾ inch crushed stone. Alternatively, you can fill the hole with crushed stone up to the top of the hardpan and cover the top with filter fabric to keep fine particles from working their way into the crushed stone and plugging it up.
Install chimneys at three to four foot intervals where needed.
Corrugated pipe drainage systems:
A common but labor-intensive method is to install corrugated pipe drainage systems, as they are good for most soggy soil and standing water conditions. They are also good for areas where excess run-off causes flooding and erosion during heavy rains because they shed water quickly.
Dig a trench about 2′ deep and 1′ wide. Start the trench in the lowest part of your drainage problem and continue it to the nearest area where the water can run-off to. Be sure to pick a discharge spot that will not create new drainage problems for you or someone else.
After digging the trench and before you lay the corrugated pipe make sure the trench can support a slope of at least 1/8“ per foot. So for every 8 feet the slope of the pipe should drop one inch. You can use a string and a string level that has slope increments on it to maintain this slope over the length of the drainage pipe. Or you can position the string and set the slope manually using your Garden Tutor measuring tape. Once you have set the slope, line the trench with a filter fabric, then line the bottom with a layer of 3/4 inch stone and follow the slope string you placed in the trench.
Consider using a filter fabric sleeve that can be fitted over the corrugated pipe. This provides an additional layer of protection against sediments building up inside the pipe and eventually clogging it. Add a catch basin or drain at the main water collection point.
Then lay 4″ perforated drainage pipe in the trench. Make sure the perforations (small holes/slits) in the pipe are facing upward. This helps keep sediments from building up inside the pipe over time. Double check the slope and adjust as needed by adding or removing the crushed stone, then cover the pipe with about 4 inches of 3/4″ crushed stone. Cover the stone with filter fabric, then back fill the trench with good soil. For long drainage runs you may need to dig a deeper trench.
Note: You can run a garden hose at the high end of the pipe to make sure water is draining properly and you have the right slope. Be sure you get the slope right before you begin covering the pipe with stone. Once the pipe is covered it will be very difficult to adjust.
If you have major drainage problems you should consult with a drainage expert.