How much sun does the site receive? Ideal areas for vegetables, fruits and many flowering plants will receive 6 to 8 hours of sunlight each day. A good number of perennials, ground covers and shrubs can tolerate or even prefer partially shaded conditions. Few plants, however, perform well in heavy shade. It usually makes sense to select plants that have light requirements similar to those your site offers.
Another factor to consider is drainage. Does water puddle in this spot for long periods after a rainfall? This may indicate compacted soils, a hardpan layer, or a site with a high water table. Since most plants require good drainage, these areas could be physically amended, avoided or in the case of soggy soils, planted with species adapted to moist conditions.
Is the site especially sandy or gravelly? Water drains too fast and plants may be susceptible to drought. Additions of organic matter will increase the amount of water the soil holds. Otherwise, seek out plant species that tolerate dry soils.
Soil nutrient testing is an easy and efficient way to determine the pH and nutrient levels of a garden soil. Soil tests are inexpensive and recommendations are made for the amounts of limestone and fertilizer to apply if necessary. The pH of the soil is very important as it affects the availability of all plant nutrients.
Adjusting the pH and nutrient levels before planting ensures a healthier more productive garden. For information on soil testing, contact the UConn Soil Nutrient Analysis Lab at 877.486.4274 or visit their website atsoiltesting.cahnr.uconn.edu.
METHODS TO ESTABLISH A GARDEN BED
The traditional way to establish a garden bed is to remove the existing vegetation, loosen the soil and mix in amendments such as organic matter, limestone and nutrients. This tried and true method has worked well for generations of gardeners. Sod and other vegetation can be dug up by hand, rototilled and raked, or sometimes eliminated with a sod cutter.
If an organic amendment containing low levels of nitrogen or phosphorus is used, like peat moss or leaf compost, the soil can be tested before the organic matter addition. This way the organic material along with the recommended amounts of ground limestone and fertilizer can be incorporated at one time.
When organic materials that contain high levels of nutrients such as manures and some composts are used, it is better to mix no more than 1 inch of these into the soil first, then test the soil for pH levels and nutrients. Applications of organic materials containing relatively high levels of nutrients can increase the phosphorus content of the soil to levels that can be environmentally harmful. Often limestone or other sources of nutrients may not be necessary.
When preparing garden beds in the fall it does not make sense to add a source of nitrogen unless beds will be planted shortly after preparation. Nitrogen added in the fall will likely be leached from the soil during the winter and early spring. Nutrients like phosphorus and potassium can be added if a soil test indicates that they are at insufficient levels. Slow release, organic sources of phosphorus include rock phosphate and bonemeal. Greensand is slow-release mined mineral containing potassium.
BEDS IN HEAVY SOILS OR COMPACTED SITES
In areas where the soil is very compacted, fine-textured and heavy, or where an underlying hardpan layer exists, double digging can be performed. Double digging loosens the soil to two spade depths. It is hard work but yields impressive results. To double dig a bed, start at one end and dig a one-foot wide trench to the depth of your spade or shovel. Place the topsoil in a wheelbarrow. Next, using a garden fork, loosen the subsoil to the depth of the tines. Limestone can be worked into the subsoil when loosening it if the pH is low. Repeat this procedure with the next one-foot strip placing the topsoil into the first trench. Continue until the end of the bed is reached using the soil stored in the wheelbarrow to fill the last trench.
To finish the double dug bed, top with 2 to 3 inches of organic matter and work it into the top six inches or so of soil. A mixture of organic materials is best. For example, one inch of a high nutrient manure and two inches of low nutrient leaf compost or peat moss. The goal is to incorporate adequate amounts of organic matter but not to boost the nutrients to excessive levels. The incorporation of organic matter is a key step. Organic matter will improve the soil structure creating a more porous rooting medium that will drain well and be permeable to air yet hold moisture and nutrients. Organic matter also provides food and energy to beneficial soil inhabitants like earthworms, moderates soil temperatures and releases nutrients as it decays. An ideal organic matter level for many cultivated plants is between 4 and 8 percent. Some native plants and those adapted to especially well draining soils may prefer lower organic matter levels. A soil test can evaluate organic matter levels. Ground limestone, phosphorus and potassium if necessary, can be mixed into the soil along with the organic matter.