I’ve literally done thousands of consultations pertaining to horticulture.
As an ISA-certified Arborist with many years in the nursery industry and even more designing landscapes, I’ve seen just about every problem that can be encountered when it comes to maintaining a healthy garden. The potential for having a garden that thrives is simple when you have the basics implemented when you start.
After thousands of visits to people’s homes I will share my findings. Countless times the problems are the same for plant disease and failure.
First, let’s examine a tree and how it functions. The stem, which will become the trunk, is the support device of the tree, but just under the bark is the water and nutrient pipeline. That pipeline is tissue that brings water from the extensive root system to nourish thousands of leaves or needles, depending on tree species and age. It is paramount to protect and preserve this tissue. Once this tissue zone is damaged from either rot or mechanical damage, the tree above that point will die.
Water saturation around the stem from standing water for days at a time is and can be deadly for many species of trees and plants. Cherry trees .dogwoods and azaleas are especially problematic.
Now look at my photo of a nearby almond orchard in Wilton, as the rancher is doing a great job creating a healthy growth environment. Notice how the trees are planted on either a mound or ridge, as all orchards usually are. Ever wonder why? This planting technique is one of the most important steps in clay soil for tree longevity in clay soils.
By planting high, during high rainfall periods, the stem of the plant will never become overly saturated at the soil grade. Water may stand in the road areas during and after rainy periods, but the crown of the tree will have air infiltration.
So with that, remember to plant slightly higher than the grade – it doesn’t need to be a giant mound – just slightly higher to drain water away from the crown. I have seen hundreds of dead and sickly trees because they were planted in low-swales – this creates the rot as well by making a soggy bath for fungi to breed and attack the thin skin or tissue of the tree.
Just think of it as being like your tooth that’s anchored into your gum line. What would happen if you put a sugar packet around your tooth every day for a couple of weeks. The sugar would create a rot situation similar to our tree/water scenario.
Improper watering is the single biggest problem in new plant establishment. When you buy a tree from the nursery during this time of the year, it’s a risky time for a number of reasons. First off, the nursery is watering every day. Yet, many salespeople instruct you to water your planted tree at home once or twice a week – that’s utter nonsense when temperatures are 80 and above. Until the plant roots out into your native soil, the roots are still in the nursery pot soil. So with that, you’ll want to continue to keep that zone evenly moist, and provide moisture in the transitional zone of your native soil to allow exit growth roots to venture out.
I am always asked “how often do I need to water and for how long.” Sorry to say, there is no definitive answer, as every irrigation system is different depending on many factors such as spray or drip system, how many gallon per hour emitter are being used and how many are on the line, and so on. The only way to really know what’s down there is to run the system for an amount of time and then physically examine the soil. Is the root ball fully moistened and is the soil beyond moist as well? This is what you’ll need to do. It’s happened to us all. You buy a plant in August, plant it, and four days later it’s brown and crispy. Fess up, it was you, not the nursery that did something wrong – it didn’t get enough water.
Next in the photo you’ll notice the watering of the almonds by the soil darkening. The drip system provides adequate water for the small trees, but do remember that roots continue to grow in an outward fashion. The weight mass of a root system can nearly match the above ground portion of a tree so as time goes by, both the upper and below ground structure spreads. Because the roots aren’t seen, we don’t think about them. It’s now known, that 60 percent of the root mass, in most species, spreads beyond the tree canopy. Roots won’t grow into dry soil. You can see how important it is to provide water further and further away from the trunk of the tree as it grows.
With the recent homebound situation one good outcome is the back-to-roots feeling that abounds now. Trees are important – now more than ever.
Rod Whitlow is an ISA Cert. Arborist and Plant Science Editor for the Sunset Western Garden Book. www.RodWhitlowDesign.com.