First, it is critical to have your soil tested. Rather than buying a pH plus NPK kit at the nursery, I suggest mailing samples to a quality soil testing facility. Starting at around $15 per sample (about the price of a DIY kit that does much less), these labs will analyze your soil based on the crop you plan to grow. So in addition to telling you if your pH is off or if your Potassium levels are off the chart, they'll tell you how to adjust the soil to correct for such problems. Plus, labs will be able to warn you if your soils contain toxic levels of heavy metals like lead or cadmium. Frankly, you can't test for these with a cheap DIY kit. And, you shouldn't be growing food without confirming your soil is safe. Remember: a plant can take up, store and then feed you toxics without you knowing! (UMass Amherst Soil lab is a great option for starters.)
Okay, so now that you know your soil is safe for growing food, your second step is to decide where you want to grow your crops. Most seasonal edibles require a minimum of six hours of quality sunlight to produce well. When you select your best veggie bed location, remember to consider what the sun will be like during the time of year you plan to do your growing. A bed in full shade in January may be in hot, late day sun come June!
· In a lot of shade? Consider native berry shrubs like Serviceberry, Evergreen Huckleberry or Salal.
· Only have room for a couple of containers? Consider mixed leafy greens like lettuce, colorful beets, trailing rosemary, mingled with pretty, edible nasturtiums and Johnny-jump-ups.
· Need to finish the edge of a patio? Try low-growing herbs like thyme, creeping oregano, a carpet of baby mixed greens or even seasonal bush-beans.
· Or maybe you want something low maintenance with low water requirements that offers evergreen interest. Consider woody herbs like rosemary, lavender and sage.
· Have room to grow up or need a fence-like structure? Contemplate adding trellising or hogwire fencing on which to grow vine-like plants such as squash, cucumber, scarlet runner beans, or tomatoes.
· Boxed in by walls? Try planting espalier fruit trees against it to decorate the space, increasing your harvest and adding interest.
· Love your colorful annuals but want to add texture to your beds? Opt for carrots for mid-tier fluffiness or combine rich-colored coleus with blood grass and rainbow chard annual eye-candy.
Before you get started, it is critical you know your tolerance. Pests will attack your edibles. However, if you know which pests like which plant groups, you will be able to protect your crops with techniques that preclude pesticide applications. Through the use of hardy, locally grown starts and seeds your plants will be armed to survive in your area. By employing careful crop rotation management you will break pest and disease lifecycles. By tolerating hiding a few plants now and again with floating row cover, you will keep pests from making your crops tasty homes for their young. And, by being ruthless and removing and destroying any infected plants the moment they show disease issues, your overall cropping will likely be salvaged.
Truly, the possibilities for gaining maximum bounty in minimal spaces are nearly endless. In my own mid-sized residential garden in Seattle, I took on a personal challenge in 2009 to grow enough food to feed my family and share with others. For 28 weeks running during the high growing season, I was able to take a plentiful harvest each week to our local food bank while still feeding my family, preserving food, and sharing with friends from our partially edible but mostly ornamental garden beds. In 2010 I hope to increase my donation volume while exploring new crops and trying new techniques. I encourage you to do so as well.