(Click on photos to enlarge)
Wood is the most popular frame for a raised bed and is the easiest to build, but concrete block in this neck of the woods lasts longer. With end caps resting on top of the block I also have a nice wide sitting area to work from. The thought of gardening on my knees is NOT how I see myself spending my golden years! So, after calculating what I needed for two 4' X 8' beds, I went about purchasing the following:
Since my last post two years ago I retired from the credit union after 34 years of service. I was blessed with a rich and wonderful career and find I am still passionate about the credit union movement. BUT, retirement is awsome and I am excited with every morning the Lord gives me.
My desert garden keeps me busy, but since adding battery operated automatic timers to my irrigation system, including all outside potted plants, I have found time to start a vegetable garden. I have always wanted to grow my own vegetables, but it took the urging of my 8 year old grand daughter Amber Rose to get me going.
In the Tucson mountains, much of our soil is quite horrible. Most of it is interlaced with caliche - a hard white crumbly substance that prevents easy planting. It is also rocky and alkaline and needs amendments galore to support growing vegetables and anything else not native. To get around this, many desert gardeners construct raised beds to allow for easy soil management and planting. Using Mel Bartholomew's book "Square Foot Gardening" http://squarefootgardening.com/. I began constructing my raised beds towards the end of July. Square foot gardening allows you to grow more in less space. Gone are the 3 foot spaces between rows and the majority of labor normally associated with tending your garden.
My first challenge was finding a location for my beds. Javalina and rabbits would love the tender vegetables, as would the many birds that now visit our desert sanctuary daily. My grand daughter suggested using our old dog run area which is protected by a chain link fence on the Northwest side of the house. NOT the perfect location exposure wise, but being already protected and close to a water source I decided it would do.
Wood is the most popular frame for a raised bed and is the easiest to build, but concrete block in this neck of the woods lasts longer. With end caps resting on top of the block I also have a nice wide sitting area to work from. The thought of gardening on my knees is NOT how I see myself spending my golden years! So, after calculating what I needed for two 4' X 8' beds, I went about purchasing the following:
Split faced block (8" X 8" X 16") and end caps (8" X 2" X 16")
Heavy duty pond liner (Home Depot)
Wire mesh (heavy duty, 1/4" openings)
Weed Block
I laid the block without mortar and directly on the ground. If you want an attractive looking structure keep a level and string handy to make sure the block is level and straight. The split faced block is very handsome looking and costs just a little more than regular block. I considered the newer inter-connected block you can find at the big box improvement centers, but be prepared to pay about double the cost of split faced block.
I used pond liner to cover the inside sides of the bed. It is not necessary, but I was concerned about excess evaporation. DO NOT use the liner to cover the bottom of the bed (unless you change your mind and want a wading pool instead of a garden bed). Weed block fabric is placed in the bottom of the bed and covered with the wire mesh to keep both weeds and gophers out. Don't skip this part. We have gophers all around us who would love to take up residence in a nice cool, dark place.
IRRIGATION: I love drip irrigation. It is cheap, easy to work with and conserves water. Mel Bartholomew recommends watering your plants by hand using a pail of sun warmed water. This would be fine with a smaller 4' X 4' bed back East, but in Tucson where 100 plus degree days are common, I would be spending all of my time watering and worrying. All you need is enough 1/2" irrigation hose to go from an outside faucet to each bed, and then enough to run two hoses adjacent to each other the length of the beds. (Click on photos to enlarge)
The sprinkler heads I chose are made by "Dig" and allow you to adjust the volume of water that is emitted by turning the heads clockwise and counter clockwise (truly a tremendous leap forward for drip systems!). I have placed one every 12" in between two squares. I may change this to one every 6 inches, but want to experiment with this placement for the time being. Having two beds and seven large pots I ran three 1/2" lines, one to each bed and one to my collection of fiberglass whisky half barrels and two old enameled sinks. You can purchase a multi-hose connector (up to four) which allows control of your three zones plus faucet connection for your garden hose. The timers are battery operated, and will allow you to water each section separately. All of these items can be purchased at Home Depot.
SOIL PREPARATION: OK, here is the IMPORTANT part. Mel Bartholomew has been working on his soil mix since the 80's. According to Mel, his soil mix allows superb moisture retention (a must in the desert) excellent drainage, all the proper nutrients WITHOUT adding fertilizers and you will never have to turn your soil. Too good to believe? I'll let you know, but so far the stuff is fantastic. His recipe follows:
1/3 compost - compost must be made from at least 5 different types of bagged compost. Weird, yes, but he has his reasons.
1/3 COARSE Vermiculite - You can also find this at some Home Depots. Very expensive, but a must have. I had to settle for medium grade. Mel stresses coarse if you can get it. Don't substitute Perlite.
1/3 Peat Moss
Mel's tip to use a tarp to mix the ingredients together makes this part go much faster. I started by dumping 2 shovel fulls each from the 5 different compost bags on the tarp and mixed together by pulling the corners of the tarp around. After the compost is well mixed add 10 shovels full of the vermiculite and 10 shovels full of the peat moss. Again, pulling the corners of the tarp around mix the whole batch together. Mel's mix is light enough that I was able to heave it easily over the walls of the raised bed. Mel swears you only need a 6 inch depth of mix to grow most vegetables. I went a bit farther and ended up with 10 inches on average. The ingredients for this mix is expensive stuff, but if his claims are true, I shouldn't have to replenish ever again.
The secret to keeping Mel's mix nourishing and maintaining your plants for years to come is home made compost. About 10 years ago my wife went to a beginner's composting class and came home with a roll of vinyl with large holes in it. Until now, it has taken up space in my storage room. Knowing home made compost is an essential step for success, I've taken the plunge. I'll let you know in future posts how all this works out.
The "hoops" constructed over the beds provide a means to easily protect your garden from sun, birds and varmints. Using 1/2" PVC conduit the hoops are easily constructed and connected by small screws at the top. I used rebar for the ends of the conduit to slip over to provide additional stability. Now I can place bird netting, sun screening, tarps etc. over the beds to control just about any situation that would be harmful to the garden.
Vertical Structures
The whole idea behind square foot gardening is growing more in less space. I urge you to read Mel's' revised book called "All New Square Foot Gardening" and visit his website listed at the beginning of this post. Eventually, anything that can climb (tomatoes, cucumbers, peas, beans, etc. ) should be trained to climb away from the garden to allow more space to grow other vegetables. Based on Mel's' recommendation, I used 1/2" electrical metal conduit and polyester netting to construct four 6' structures for this purpose. Cutting the conduit is easy with a hack saw and slipping the ends of the metal conduit over 24" rebar provides the necessary stability needed. 90 degree corners and the necessary connectors hold all of this together. Again, Home Depot is the place to pick these things up.
The Grids
I must admit I was a bit reluctant to install square foot grids as Mel recommended at first. They looked gimicky to me. BUT, if you want to save time sowing seeds and organizing your garden it is a must. I used slats
from four foot vinyl blinds and stapled them together with a regular hand stapler - cheap, quick and easy. When it comes time to calculate the spacing between seeds or transplants you'll be grateful you did. I also diagrammed my two beds and collection of whisky barrels to help me remember what I planted where, the date planted, and seed/plant type. This way, if something works (or doesn't work) I won't have to rely on my memory.
So that's it for now. I'll keep posting to this site to keep you updated as to my progress.
from four foot vinyl blinds and stapled them together with a regular hand stapler - cheap, quick and easy. When it comes time to calculate the spacing between seeds or transplants you'll be grateful you did. I also diagrammed my two beds and collection of whisky barrels to help me remember what I planted where, the date planted, and seed/plant type. This way, if something works (or doesn't work) I won't have to rely on my memory.
So that's it for now. I'll keep posting to this site to keep you updated as to my progress.
3 comments:
That's a great garden you've made!
For years I have done straight row gardening and was always limited to my tiny space. I have just created some square foot gardens and cannot believe how much I was able to plant. It also looks so professional that my neighbors keep coming over to admire. The book was so helpful and has all of the necessary pictures to create everything you will need! I strongly recommend this concept to anyone with limited space!
Great website, continue the Excellent work!
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