Spring is almost here in the Rockies! I have been diligently checking my soil temperatures in the high tunnel and the day finally arrived! My raised beds were above 40 degrees and the cold crops of vegetables can go in the ground!
For the last two years I have been working on a grant through the NRCS on extending the growing season for fruits and vegetables. What that means is….I try to dream up any way I can think of to extend our zone 5 growing season.
After constructing our high tunnel, one of our first order of business was to construct raised beds. These can be made of any material you wish – anything from 2 x 4s, 2 x 6s, even larger lumber like 2 x 12s. You can use cement block or bricks. Please avoid railroad ties and pressure treated lumber! They contain chemicals that could leach into your soil and get into your plants. We only want you to grow goodness in your beds.
We used 2 x 6s in our high tunnel, but dug the soil within the bed down 6″ and mixed it with the organic matter and new soil we had brought in to fill our bed. You want to avoid just putting your new soil on top of the existing soil – it can seriously impede your plant roots from going down. Mix it up!
Raised beds give the gardener a jump on the growing season as they dry out faster after a snow or rain, and the soil warms at a faster pace than regular ground-level soil. It is easy to check the fertility of the soil within your bed and to apply any fertilizer you may need because you know how many square feet you are dealing with within the bed itself.
It's important to make your raised bed only as wide as you can reach across from each side. For me, my beds are four feet wide. I can easily reach two feet across to the middle – which is very important! One of the secrets to gardening in a raised bed is you never ever want to step in it! Soil compaction is a gardener's enemy!
Have you ever heard of block planting? It's relatively new in the gardening world, but it's benefits are astounding. I remember, as a little girl, following my Dad around the garden with my bucket of seeds. One seed spaced perfectly from another in a long row. Thirty feet of beets, fifty feet of beans. A nice walkway in between each row. A beautiful garden – brings back great memories!! But even better are the results you can get with block planting.
Take carrots, for example. By planting a carrot seed every three inches, every direction, you not only increase your yield up to five-fold, but the foliage will block out the sunlight to the weed seed in your soil. Without sun, your weeds cannot germinate! We are all for less weeding – for sure! Here are a few examples of how your raised beds will look during the growing season.
As you can see, I have been able to pack a lot of beautiful vegetables into my 4' x 8' raised bed. It is easy to reach into, I have installed four 1/4″ drip line with emitters every 6″ to put that moisture right where the plant can easily receive it. Mulch is necessary in most of my beds in the high tunnel. Colorado has very low humidity and great temperature fluctuations. The mulch allows us to keep that soil moist and cool in the hot sun and helps to shield the weed seeds from sunlight and germination. The taste quality of your crop is improved also. Think of it this way…have you ever been in your garden on a hot July day? Your corn plants had received an adequate watering that morning but now the foliage is drooping and they look thirsty? You are right! Not only has your water dissipated in the sun or wind, but the plant's taste is affected with the stress. A three inch layer of mulch would have helped protect your corn from the loss of the moisture, shield the weed seeds from germination, and make your crop taste better. Bingo!!
Compare the taste of your home-grown tomatoes to any store-bought one! There is none!