Gardening Tips: May 23 2012

Raised Beds
The past couple of weeks have been very similar with rainy weather during the first part of the week, followed by beautiful sunny days for the end of the week and the weekend. This has allowed our weekend warriors from the cities and the suburbs to get the required mowing done in a timely manner. I finally broke down and bought myself a new lawnmower that has power driven front wheels, after pushing a borrowed mower for the past two seasons. I think I just added a few years onto my life by doing this! Normally, I spend a lot of time trying to figure out ways to get rid of what little lawn I still have, but now I actually enjoy cutting the grass. (At least for the first mowing!)

Last week I told you I would discuss making raised beds in light of some people wondering if they should grow vegetables in areas that were flooded last August by Hurricane Irene. There is no doubt that raised beds will improve your vegetable gardening results. Not only will the vegetables grow better but you will take better care of the beds also. It is so much easier to plant, weed and water a four-foot by eight-foot raised bed than the same area of bare ground. I have also learned that the older you get, the further away the ground is from your body and the number of bend overs you can perform decreases each year. Even getting a six-inch higher platform from the ground helps. Raised beds are rock free, have better drainage and much softer soil that the good earth as it is.

Raised beds should be framed with some sort of wood, plastic or masonry (cinder blocks work well). Ten years ago I bought some one-inch by 10-inch, rough-cut, hemlock from my local sawmill. Not only was this wood locally harvested and sawed but also it was very inexpensive and bigger than what you would normally get at a lumberyard. These one by 10s were closer to one and-a-half by 11 inches since they were not planed or finished. They have also lasted 10 years and seem to have another five years left before they collapse.

Don’t use pressure treated
In the past I have also used pressure treated wood but the people at Cornell discourage this practice because of the toxic chemicals used to make PT lumber. A study, many years ago, in Texas, tested the levels of copper, chrome and arsenic that leeched from PT lumber, raised beds and found that it was insignificant as little as three inches away from the boards, even after 25 years of Texas weather. I guess I would not use PT wood for new beds but I sure would not dismantle any existing ones that I had. PT lumber is the most common wood for making decks and other outdoor furniture. Although playgrounds with PT lumber have been dismantled locally for concerns over children’s exposure to these chemicals, I wonder how many kids are running around barefoot on their backyard PT decks?

The raised beds should be no more than four feet wide as that is about as far as anyone can comfortably reach from either side and eight to ten feet long is a convenient size also but four by four beds can grow a lot of produce also. They can be as little as six inches tall, however eight to 12 inches is better. This starts to get expensive to buy the wood and to fill it as you get up to 12 inches. A four-foot wide, one foot tall, by eight foot long raised bed will need about a cubic yard of soil.

Make sure you screw the boards to each other since nails will pull out in a few years at best. The beds need to be filled with soil of some sort and here is where you need to do some research. Buy good quality topsoil and amend that soil with peat moss, compost and organic fertilizer. A four-inch layer of peat moss spread on top and worked into the soil will make it much better. I also would add a 40-pound bag of compost, plus a 40-pound bag of dehydrated manure (not barnyard manure) for each four- by eight-foot bed.

Raised beds allow you to squeeze a bit more crop into a given space since you will be able to weed and water much more efficiently and the better drainage and higher fertility will yield more per square foot. A four by four bed can easily grow 16 stalks of corn or four caged tomato plants, or eight broccoli or cauliflower, more beans, radishes, beets, lettuce or salad greens than you can eat, and even enough asparagus to feed a family of four for a few weeks each spring. Right now I am enjoying the eighth year of fresh asparagus from a four by eight raised bed and it is the best crop I grow with the least amount of work.