Soil Preparation for Color

There are two things that really stir my passion in horticulture?flowers and trees. Naturally enough, flowering trees really get me going. The health of the flowers and trees are what really seem to make or break a landscape. Healthy, strong, majestic trees provide the backbone, while flowers add that special flourish of delicate and breathtaking beauty. Having grown up in the desert southwest, I understand there are many delicious flowering perennials and shrubs that do naturally well in our climate. But there are many other species that struggle in our native soils and extremes in climate. As a wild and crazy horticultural guy, many of these are plants that I can?t help but want to grow. But to subject them to our desert extremes without extra help seems an exercise in cruelty and futility. If we?re going to take the time to plant and irrigate these less than drought tolerant species, then we should do most everything in our power to insure their success. But how do we achieve this? What steps can we take?
 
As with so many other things in horticulture, success or failure may well depend on what we do before we even plant the first of these more delicate beauties. You know the types of plants I?m talking about here?plants like Roses, Vinca, Star Jasmine, Purple Lilac Vine, Wisteria, Crepe Myrtle, Mock Orange, and Trumpet Vine. I?d also include annual color in this batch. They are all plants which will perform better, often much better, if we?re willing to invest time and resources in the preparation of the soils from which they?ll draw their nourishment.
 
Ahhh, soil preparation?that completely unglamorous, time consuming and back straining exercise of the horticulturist.
 
The first and often most important step in good soil prep is the soil test. Unless you already have a very good idea of what the composition and structure of your soils are, it is a step that can save years of future heartbreak. A soil test will give you valuable information on those nutrients that your soil lacks, as well as any toxicity problems that may lurk. You will then have a much better idea of what nutrients you?ll likely need to provide before planting and in years to come, and which nutrients are already present in plentiful quantities. If you don?t know what you?re dealing with, then some of the nutrients you?re providing in the form of fertilization may already be there in adequate quantities, and adding more will cost unnecessary dollars, and may also create toxic conditions. So take the extra time, and spend a little more up front for a soil test from a qualified lab.
 
Once you know the nutritional composition of your soil, and you?ve laid out the fertilizer amendments you?re going to use, the next question that begs to be answered is an age old one. To organically amend, or not to organically amend, that is the question.
 
Well, I?m willing to go a bit out on a limb for this one. (A good saying for an arborist, wouldn?t you agree?) While I?ve spoken with many other fine and highly qualified horticulturists who might disagree with me, I honestly believe that the addition of good quality organic matter as an amendment directly in the soil, as well as it?s use as a mulch, is a key to creating and maintaining health in our ?non-desert? plants.
 
Organic matter in the soil has some wonderful effects. First, it takes our structurally lacking soils and creates nice and clumpy soil aggregates. Organic matter will help to loosely bind grains of sandy soil to one another, increasing micro pores space, and enhancing the ability of sandy soils to hold water. With clay soils, the tiny particles are knit together in such a fashion as to increase macro pore density. This increases a clayey soils ability to retain oxygen, that most limiting element of such soils. Organic matter also increases the cation exchange capacity, also known as its CEC. The higher the CEC, the greater the ability of a soil to receive and release nutrients. And to top it all off, organic matter will also work to moderate our pH imbalances, acidifying to some degree our alkaline soils.
 
But there?s another aspect of organic matter that I want to address. An organic soil is much more likely to be ?alive?. By that I mean, it is much more likely to provide habitat for the multitude of minute and microscopic critters that abound in healthy, rich soils. As a case in point, I maintain that I?ve seen many more earthworms in rich organic soils than I have in our mineral native soils. The conditions that make such soils more ?earthworm friendly?, also contribute to the existence of many other beneficial soil organisms, from beneficial bacteria to critically important microrhizae. Other soil organisms abound. Some are directly symbiotic with the plant, other are less direct in their benefit, such as those that further decompose both the organic matter that we?ve so painstakingly added, and that which occurs as a natural byproduct of plant growth, such as sloughed off root cells. An organic soil is a living soil, and a living soil is a healthy soil.
 
So, now that I?ve sold you on the importance of organic matter for non-desert plants, you need to choose a good quality organic amendment. When I use an organic product based on a mixture of animal manure and wood products, I want to have a difficult time telling what portion of it is wood. I want the woody material to already be broken down to the extent that it?s basically unrecognizable of such. If not, there?s a good chance that much or all of the nitrogen in the organic matter will be tied up for years to come by microbes decomposing the wood. Not only that, but the existing available nitrogen in your soil may also become unavailable to your plants. If however, the wood is already well decomposed, much of the nitrogen robbing work that needs to be done has already occurred, allowing nitrogen to remain free and available. Additionally, the organic matter is closer to that stage known as humus, that stage of organic decomposition immediately preceding the release of nutrient elements. When using animal manures, I tend to stay away from steer manure products, because of their higher salt contents. (I already have enough problems with salts, thank you). If given the choice though, reed sedge peat is what I like to use. It seems to have a tendency to remain as an organic in the soil for longer periods than most other products.
 
It?s important to remember that the organic matter you so painstakingly incorporate into the soil will, in time, disappear, as it breaks down and is consumed. Well, here?s the good news. It?s much easier to maintain the organic content, than it is to create it. To maintain higher levels of organic matter, simply use it as mulch. Undecomposed chipped or shredded wood products work well, for they slowly decompose, replenishing the organic content of the soil beneath. Simultaneously they provide the excellent benefits of increased water retention and temperature moderation. You need only replenish the mulch, as it too slowly disappears.
 
Keep in mind that as the organic matter disappears, it will show up elsewhere, in different form. It becomes an integral part of those healthy perennial flowers we so love to see in our landscapes. I can honestly say that I?ve never yet regretted the extra time and money I?ve put into preparing healthy soils for my non-desert flowering plants.