Create a Raised Vegetable Bed, Part II
Let us continue the process of building a raised bed vegetable garden, which I began in last week’s column.
After laying out the boundaries, paths and beds on graph paper, plans for watering must be made. Hand watering is workable only for a small garden. Overhead watering with sprinklers wastes water. A drip system is easier for the gardener and preferable for the plants. It can be installed by professional irrigation companies and can even be put on automatic cycles, requiring minimal attention thereafter. These pipes will last for years and the cycles can be readjusted as needed. Or you can install a system yourself.
The system I put in my garden is made using soaker hoses. They’re connected from bed to bed by heavy duty garden hoses. The garden hoses are buried between the beds and are connected to the soaker segments with plastic pluming parts (PVC irrigation nipples and clamps). Using this method, several beds can be connected and several zones can be created. Each zone is connected to a hose manifold (available at a hardware stores) that is attached to your spigot. Each zone-hose needs a valve at the manifold. To water the garden, open the spigot and open the valve. This system is less expensive than a professionally installed one, but the soaker hoses will need to be replaced in 5–6 years. Regardless of how the system is installed, at the end of the season it should be “blown out” to prevent bursting hoses. Note that my system will need to be installed as you install the boxes.
Amendments like compost will be added to the beds each year, and they will not become compacted by foot traffic. The soil level will thereby grow in height so the boxes should be as tall as possible. I use 2”x12” treated lumber that is available at a lumber yard. It is safe for food growing. Locate the boxes according to your graph paper plan. They must be level and set on the soil with no spaces between the ground and the boards. Join them at the corners with a “but” joint. It is best to reinforce the corners with long 4x4s that are dug 12–18 inches into the soil. This reinforces the corners and fixes the boxes securely in place. Install the underground irrigation hoses at this point.
A product called top soil is available from several sources in this area, but I have found none that is useable for raised beds so the method I use is as follows: After placing the boxes and installing the hoses, I turn over the soil inside the boxes as deeply as I can manage (ideally at least 12 inches) being very careful to turn any grass completely upside down. This prevents the soil from growing and begins aerating the soil. Let this soil lay for two weeks. It does not need to be raked out but, if it is still clod-like after two weeks, chop it with a sharp bladed spade. This will level it out. Take a pH test at this time to determine if it needs to be adjusted. If so, add appropriate amendments now. Then add two inches of compost. Let this lay another two weeks and then chop the top with a shovel or trowel, going down 6–8 inches. This is all of the mixing necessary. (Hence the need to build these boxes as soon as possible, or even in the fall)
Well-composted manure or dried manure can be added before the compost. However, I am probably one of few organic gardeners that use no animal products in the garden. Food animals are given hormones and antibiotics throughout their lives, and I do not want these in the soil. I have read that even composting under ideal conditions does not remove all of them.
In my experience, by building the soil in this manner, it is ready for planting the first year. I never turn the soil over again. Each year I add at least two inches of fresh compost, worm castings and any other appropriate amendments. They will be mixed into the soil by earthworms (the more in the soil the better) and with the act of planting seeds and plants.
Though beginning a garden like this involves time and money, if done right, it only needs to be done once.
Jeanelle Myers is a professional gardener and consultant. For gardening discussion you can call her at 631-434-5067.