When something goes wrong in the garden or yardscape, the first inclination most times is to look for a bug, pest or other invader. It’s true that insects, animals, viruses and bacteria can cause problems. However, there are a lot of areas where we can cause problems and not even know it.
These are self-inflicted wounds to our garden space that can be avoided with just a bit of knowledge and implementation of different practices.
At last month’s Master Gardener public presentation, my friend Justin Wiker gave a talk on “What’s Wrong with my Garden?” Justin is a really smart guy, so I’m unabashedly plagiarizing his comments.
Starting out, he gave us two words that are used for two different categories for things that go wrong in our gardens. Those terms are biotic and abiotic.
The things that are living in your garden or an ecosystem are termed biotic factors. This would include stuff like fungi, plants, animals, bacteria and people.
Those parts of an ecosystem that aren’t living are called abiotic factors. These would include soil, rocks, temperature, sunlight, wind, the atmosphere, water and conditions around a planting such as sidewalks, roads, walls and reflected light from adjacent structures.
Well, it doesn’t take a rocket …, um, I mean, a soil scientist to see that both abiotic and biotic factors can have strong influences on success or failure in your horticultural pursuits. There are some things in these lists that you have very little, if no control over.
Some you can influence to a degree, but not totally eliminate. A few you have almost complete sway over. Once we understand what some of the outcomes of our gardening choices and actions are, we are a long way toward solving a strong majority of horticultural challenges.
Justin believes that somewhere between 80 and 90 percent of plant and tree problems are caused by … us. And with that declaration, here’s Justin’s top 10 abiotic issues and what to do about them.
•Issue number one is iron chlorosis. This is when the plant can’t produce chlorophyll in adequate quantities and the typical leaf color is significantly different (green leaves will look light lime green) than the same plant without an iron deficiency.
How would we cause that? Typically, poor plant or tree choice for our area. You see, there is plenty of iron in our soil, but it’s not in a form that is readily accessible for plants. That’s because of the high clay content and electrical charge between the iron and clay molecules. The attraction is so high that the roots of the plants can’t pull off the iron (so forget about adding old iron or iron filings to your tree wells – it won’t work).
Early in the season, all looks fine, as less iron is needed. When the iron moves into the leaves, its location is fixed; it can’t move.
So, earlier growth looks green, but as the season progresses, the leaves suffer from the lack of iron that is needed to make chlorophyll. What to do? Choose varieties that do well in our area and don’t suffer from iron shortages. Existing trees will have to either stay that way, be treated with forms of iron that will give short term boosts of iron (a chelated form, making the iron more water soluble), or be removed and replaced with a more suitable choice.
•The second main problem is planting depth. Yep. This seems to be too simple to be true, but it is. If the plant is too deep, it can rot. If it’s a variety that is grafted to a rootstock, deep planting can allow the root to produce top growth.
If the plant is too shallow, it will likely die as the roots dry out and their tissues are exposed to an environment they were not designed to be in. Being precise in planting depths will pay strong dividends.
•Number three is girdling roots. These are roots that can be formed when the tree or plant is in a pot and is actively growing. The roots are going to go “on the hunt” for additional space and nutrients. As they do, the circular shape of the pot creates the problem.
Sometimes these types of roots will form on their own in a planting hole that we didn’t make the hole sizable enough or we neglected to rough up the side of the hole to give roots something to grip onto and penetrate into. The solution? Cut these types of roots off before planting from a pot, then be sure to give the new planting plenty of water for the first season. Water can be reduced the second year as the planting gets established.
•Mechanical damage takes slot number four. This ranges from string trimmers to mowers, tractors, cat scratching, glancing blows from shovels and the like. Exercise caution around your trees and plants, and in some cases, consider some loose fitting sleeve materials until tough bark forms.
•Number five is a head scratcher, but it happens when shortcuts are taken during planting. Would you believe that a lot of plant and tree problems occur because the packaging material was left intact or not completely removed? The cure for this one is self-explanatory. Yes, even remove burlap bagging.
•Our sixth issue is more common than you would think for our arid valley. Overwatering. This happens when our mindset is something like, “if a moderate amount of water is good, then extreme amounts must be even better.” The fact is, overwatered plants will behave strangely like plants that are in drought. There are two primary reasons for this.
First, the roots need oxygen. It is typically delivered when appropriate amounts of water moves down through the soil, bringing oxygen with it into the micro-spaces in the soil. If too much water is applied, these spaces are filled with water, and the plant suffocates, in essence drowning. Roots don’t have gills, after all.
Second, having roots trapped in soil that is constantly wet leads to rotting. This kills the roots and starves the plant from the nutrients and air it needs. When it comes to water, do the minimum. Water deeply and less frequently, and you’ll see the difference.
•The seventh is one that many of us have seen around here; summer scorching of leaves. Again, while it is not us, but the sun, that is doing the scorching, we are complicit in the matter as well because of our planting choices. Large-leaved tree and shrub varieties will tend to scorch significantly more than smaller leaves. If having scorch is a problem with the existing plantings you have, consider augmenting them with alternatives.
•Number eight is herbicide damage. This usually occurs when an adjacent area is treated with a broadleaf weed killer. Depending on the type of application, toxicity can migrate through the soil and enter your plants via the root systems. If the herbicide was sprayed when it was very warm or hot, or when it was breezy, the product can atomize and easily drift to your plants, where the poison enters via the leaf surfaces. Be careful how you apply, and keep an eye out for applications by others on properties and spaces adjacent to your yardscape.
•Winter damage comes in at number nine. Planting varieties that are not well adapted can be one reason. An equally common one is fertilizing and significant water application in early fall. This stimulates growth that is tender and still full of moisture when the cold arrives. This new growth has little chance of survival over the winter.
•Last, but not least, is salt damage. This can be from street surfaces or when we salt sidewalks and driveways. Most plants are not salt resistant and can only take a moderate amount of sodium chloride before they are compromised. Salt enough to maintain safe surfaces, but take it easy. Your yard and plants will thank you.
Again, a special thanks for Justin Wiker for these great insights. I hope you find them as useful as I did.
Jay Cooper can be contacted at firstname.lastname@example.org, or you can visit his channel at youtube.com/dirtfarmerjay for videos on the hands-on life of gardening, shop and home skills, culinary arts and landscaping.