Soils ain’t Soils ….. A Dirty Story
First it should be pointed out that dirt is always called soil in gardening. Soil is arguably the most important component in a successful garden,. And, while you may work with “soil” in your garden, you end up “dirty” …. go figure!
So take care of the soil and the plants will take care of themselves as most garden problems are caused by poor soil.
Good Garden Soil
Soil is generally evaluated on fertility and texture. The combination of essential nutrients and a pH that makes these nutrients available to the plants determines fertility. Texture refers to the size of the soil particles and their cohesiveness.
The three primary nutrients used by plants are potassium, phosphorus and nitrogen.
Nutrients
Nitrogen gets used up by your plants and by decaying matter in the soil and so is exhausted fairly quickly. Being water soluble it washes out of the soil rather quickly too. But, remember don’t over compensate when applying nitrogen – an excess of nitrogen will result in a lot of foliage growth at the expense of flowers and fruit.
Nitrogen provides for healthy leaf and stem growth.
Nitrogen fixing bacteria converts nitrogen into nitrates, into a form plants can use.
Phosphorus, on the other hand is for flowering and fruiting and root growth. Hence something like bone meal is great for bulbs. Look for products that say “flower boosters”.
To keep plants growing and healthy is the role of potassium. It boosts the natural plants immune system, but like the others is water soluble and needs to be replenished periodically, especially in pots.
Besides the three primary nutrients, there are several trace elements that are necessary for good plant health like: calcium, magnesium, zinc, molybdenum, etc.
pH
The only sure way to know what your soil’s pH is, is to have it tested. If you are changing the ph in your soil, remember that it will revert to the original ph unless repeated treatment occurs. Most nurseries have inexpensive test kits which are easy to use.
A lot is made of soil pH. In laymen’s terms, pH is a measure of the soil acidity or alkalinity. The scale goes from 1.0 to 14.0, with 7.0 being neutral.
The lower the numbers go from 7.0, the more acidic the soil. The higher they go above 7.0, the more alkaline.
Ph is important as nutrients only become available to plants if the soil falls into certain range they require. This varies with plant types.
For example, rhododendrons, azaleas, blue hydrangeas, heathers and blueberries favor very acid soils and white to pink hydrangeas, lilacs and clematis will thrive in alkaline or even chalky soil.
The low acid to neutral range (6.2 – 6.8) is generally suitable for most plants, but check to see if your plants requires more extremes of ph.
Texture
Texture Refers to the size of the soil particles.
Sandy soils have very large particles which allows water, air and plant roots to move more freely. At the other end of the spectrum is clay.
Sandy soils can be problematic in that the drain too much, washing away nutrients too quickly.
Clay as the opposite tends to become water-logged – and is only good for plants that require wet feet. It is also harder to work with a shovel or fork.
Luckily, most soils come in-between – though even then they will need good compost and mulching. The ideal is sandy loam. It allows for air movement and water penetration without excessive retention or too little. Organic matter assist maintain this state.
An easy test for soil texture is to make a ball of damp garden soil. If it breaks apart when you tap it, it’s sandy. If you can press it between your thumb and finger and make a ribbon, it’s clay.
Don’t try to change your soil texture by adding sand to clay or vice versa.
That is a recipe for cement. Some amendment recommendations for clay do include a portion of very fine sand, but there are better ways to change your soil texture, such as adding gypsum or organic material
