There are many aspects to good garden care, but there are two in particular that are crucial for a healthy, beautiful and thriving natural landscape - and two that most landscapers do poorly - namely how your prune your woody plants, and how you take care of your soil.
Soil stewardship involves working with the soil food web - the billions of tiny creatures that are present in healthy soil - so that they can work for you and your plants by providing them with the nutrients, soil structure, and disease resistance they need in order to reach their full potential. Most landscapers work against the soil food web by removing all of the organic matter, and effectively starving these beneficial organisms, in an effort to leave things neat and tidy. In the long run this leads to stressed, unhealthy and sad looking plants. You can practice good soil stewardship AND have a beautiful, tidy landscape, all the while reducing greenhouse gas emissions by turning the abundant organic matter in your yard into compost and mulches.
To prune well requires in-depth knowledge of not only the plants being pruned but also how they will grow in response to the cuts you make. Most landscapers rely far too much on the hedgetrimmer which, like all tools, has it’s place, but when used inappropriately can greatly diminish the beauty and vitality of your plants. In contrast, making precise and deliberate pruning cuts can enhance the health, vigor, and even flowering of your woody plants.
Read the sections below to learn more about how I use the principles of good pruning and soil stewardship to enhance the natural beauty of landscapes in a holistic and sustainable way.
To me, probably the most important part of garden care is using practices that enhance the soil and work with the soil food web. Through the use of compost and mulches, I can improve the health of your soil, help your plants look healthy and beautiful and your landscape tidy, and save you money in the long term, as well as reduce greenhouse gas emissions. Contrast this approach with what most landscapers do when they scrape away every last bit of organic matter, leaving landscapes that are starved of nutrients, less resilient to drought, and open to pests and disease.
I've seen first hand the effect that this has; before starting my own company I worked at a few sites where I saw how year after year of taking away all the organic matter and never replacing it with compost or mulch, the plants became more sickly and unpleasant with each season. This was a particularly sad thing to see in gardens that started with a beautiful design, and something that I'm committed never to repeat.
Aside from the need for starting with a good garden design where plants have been placed where they are most likely to do well, it should be obvious that in order for plants to thrive and be healthy they need to be rooted in good soil. But what exactly is meant by “good soil” is not as obvious.
The answer is that good soil is “alive” soil - teeming with literally billions of microscopic organisms, comprising a food web that starts with invisible bacteria and fungi all the way up to earthworms and other clearly visible insects. In the course of their living and dying, eating and excreting, they make the mineral nutrients that plants need available in forms that plants can readily absorb through their roots.
What’s more is that plants and these microorganisms have evolved together and have formed symbiotic relationships that benefit both. Plants can create sugars via photosynthesis, and through their roots they share these foods with microorganisms in exchange for greatly increased access to nutrients and water, like these micorrhyzal fungi which have formed a network with the roots of this plant.
Nobody has ever had to water or fertilize an old-growth forest, instead they are able to get all the nutrients they need for their spectacular growth from the richly diverse soil ecology they are rooted in. Consider that the next time you are walking under their towering heights!
The same is true for the ornamental plants in your garden. The wild ancestors of these cultivated species would have depended on the soil food web for all of their nutrient needs and through the specific symbiotic relationships with microorganisms in their environment would have received those nutrients in their preferred form.
Not only does the soil food web provide plants with nutrients, but all of the tunneling and eating and excreting of organic material creates ideal soil structure. This allows for both water and air to penetrate easily, both of which are essential to healthy root development. And while water can enter and is retained, it can also drain easily. When soil structure is poor soil can become compacted, waterlogged, and will impede roots from growing.
The soil food web also provides excellent disease resistance. Some bacteria and fungi are harmful to plants, but when there is an abundance of diverse microorganisms all competing for the same nutrients and preying on each other, the good ones tend to keep the bad ones in check. However, when the microbiology of your soil is absent then conditions are ripe for an invasion of pathogenic bacteria or fungi.
You can clearly see the effect when microorganisms aren’t present in the soil in new landscapes that are installed around condos, houses or mall parking lots. Tonnes of virtually dead soil is trucked in from all over, and unless biologically active compost or mulch is added, then the shrubs and lawns will start to visibly suffer within a matter of months. This problem is made much worse when all the organic matter is scraped away and lots of fertilizer and herbicides are applied, which has the effect of starving and poisoning the soil biology.
You can use fertilizers to supply nutrients to your plants, but it’s kind of like getting nutrition through candy and meal replacement drinks instead of well balanced meals with all of the food groups. And use of inorganic fertilizers can start a vicious cycle. In the short term they can provide the nutrients your plants need, but they are salts which are toxic to most microorganisms. When the soil food web is diminished plants require more and more fertilizer, which the soil can no longer hold due to poor soil structure, all the while leaving the plants more susceptible to disease.
The remedy for all of this is adding good compost and mulch to your garden beds. Compost in particular is absolutely full of biological activity, and adding it generously has the effect of inoculating your soil with all of the beneficial microorganisms it needs. If you have a big yard with lawns and lots of leaves in the fall, these along with the other green waste and debris from your yard can create rich compost and mulch right in your very own yard.
There is a lot of work in setting up and maintaining a good compost/mulch system, but there is also a lot of work involved in hauling every last leaf out to the boulevard for the city to take away or to be driven to the yard waste dump. That approach leads to way more greenhouse gas emissions with all of the trucks going around to pick up leaves, and having them dumped in massive piles that get incredibly hot and release methane and CO2 to the atmosphere. And once it’s broken down you get the privilege of paying for it to be delivered back to you in the form of mulch or compost, leading to more emissions.
Instead of that you could have them composting in tidy piles or bins in an out of the way area of your yard, to be used later to enrich your soil and feed the microorganisms that are hard at work making the plants in your landscape look their best. And all for free!
Assuming your garden began with a good design then most of the woody plants in it will benefit from wise and deliberate pruning - some require a lot while others hardly need any. Pruning will always have an affect on how a plant grows in the following season, however when it’s done well and in harmony with the plant’s natural growth habit, then only a trained eye will be able to tell that anything’s been done to it. In contrast, when it’s done poorly and when it forces a plant to be a shape it doesn’t naturally want to be it can look like a chainsaw massacre - or more likely a hedgetrimmer massacre!
The hedgetrimmer is an extremely useful tool, but in general it’s best when it’s limited to clipping young stems before they’ve ripened and become woody on plants that are dense and bushy in their growth habit, and that have small leaves or foliage. It’s a great tool for keeping an escalonia to a decent size, and crucial for the proper formation of a cedar or cypress hedge. However, for a lot of other plants it’s way better to reach for the secateurs, loppers, or pruning saw.
Making a distinction between heading and thinning cuts is another crucial part of deliberate pruning. Heading cuts cut a stem part way down, and cause new stems to grow below the cut from nodes or buds on the stem. Generally this means that heading cuts will lead to bushier growth, and if done correctly can lead to more flower buds on new growth on plants like abelia grandiflora , or the development of flower spurs on older wood on an apple tree (malus) or wisteria vine. If done improperly they can spoil the elegance of a plant’s natural branching pattern by adding a tangle of new stems.
A thinning cut removes a stem at a point where it branches off. It usually doesn’t lead to any new stems popping up, but instead channels the plant’s energy to the branches that remain. This can be a great way to reduce or limit the size of a tree or shrub while keeping it looking natural instead of like a cube or beach ball, and doesn’t cause it to become bushy. Thinning cuts are also great for plants like forsythia that have multiple stems from the ground in that it can remove the oldest ones and encourage healthy new shoots from the base every year. If done improperly, it can cause extreme stress on a plant by removing too much wood.
Knowing whether a pruning cut is good or bad depends on the plant in question, the time of year, how it’s been pruned in the past, and many other factors.
Good pruning is also essential for the development of most fruit trees and many ornamentals as well. Poor pruning can lead to trees that are unbalanced with weak branches that can break off due to wind or heavy snow, or the weight of fruit that has
become too heavy for branches that should have been pruned back to encourage strength and thickness.
One of the main problems related to pruning that I see far too often is actually a problem of design where a tree or shrub has been planted in a spot where it is destined to grow many many times too large for the allotted space. “Can’t you just cut it back?” is often the question that follows, to which the answer is usually “yes, but you probably won’t like the result!” While some shrubs and a few trees will respond well to a severe reduction in size through pruning, most will not and will look terrible as a result, especially when subjected to such treatment regularly.
All plants have a genetically determined size they will try to grow to, and trying to keep them significantly smaller than what they want to be is just a bad idea. How small you can keep a plant varies with each one, but very generally trees should be allowed to grow to at least 75% of their preferred size, shrubs to 50%, and hedging plants to ⅓ their preferred size. Trying to keep them smaller is futile, and money and time would be better spent on planting something that is more appropriate for the space than on severely hacking the poor plant back every year. I’ve seen far too many english laurels - which can grow to 50+ feet tall and 30+ feet wide - forced to be a 4 foot high hedge row that looks sickly and bears the scars of many savage encounters with the hedgetrimmer. Again, all of this can be solved with good garden design.