DIY tree care before the next freeze?
The collapse of Austin’s tree canopy during the winter ice storm of 2023 is a clear sign of the precarious state of our area’s trees. Some may call for drastically trimming tree limbs to reduce downed power lines in the future. Others may be more prudent and look towards the real problem for the trees, the lack of nourishment.
How are we feeding our trees, particularly those on thinner soils? While soil testing, composting, and mulching are all great actions, another option may have a faster impact at a lower cost. It is called foliar spraying, is best done between November and April.
What is foliar spraying?
Foliar spraying involves spraying nutrients such as molasses and liquid fish emulsion, and possibly additional microbes contained in, for example, whey, onto the surfaces of the leaves, branches, and tree trunks. When applied this way, the nutrients can be taken up by the trees much more quickly and over a broader surface area. This strategy should be seen as a complement to compost, mulch, and soil testing, not as a substitute. However, it must be done during the cooler months, as spraying on hot days can burn the trees and plant leaves.
What is essential to know is that a tree that has an increasing amount of energy is much more likely to resist diseases such as oak wilt than a tree with declining energy. Since many trees may have open wounds or weakened states from the freeze, foliar spraying acts like a quick pick-me-up or vitamin shot.
What is most intriguing is the cost of doing this practice. Backpack sprayers that are modified leaf blowers are highly efficient at spraying nutrients as a fog, up into the tops of your trees, creating a fine mist that falls on the leaves. With some motion, you can see the leaves turn and the mist is falling on both sides of the leaves.
Tools
I own a Stihl backpack sprayer and have sprayed many trees with it. For those with larger properties, there is also a dry fertilizer option that allows you to loft small pellets of fertilizer over your yard, spraying pellets over a radius of 30 or more feet. Since I bought my first Stihl backpack sprayer, prices have decreased considerably. You can now buy a Tomahawk backpack fogger leaf blower for just $400 on Amazon, with free delivery. Another option is the Italian-made Invatech sprayer at $335 (Amazon). Stihl makes an excellent higher-end sprayer called the SR450, priced at $750-$950.
Foliar Spraying Tools: Stihl SR-450, Tomahawk, Invaltal
What to put into your sprayers?
The first consideration is water. If you are doing just fish emulsion and/or blackstrap molasses, then the anti-microbial water from the city is just fine. If you add microbes like those in whey, effective microorganisms, or compost tea, you will want much higher-quality filtered water. You want to make sure that the chlorine and especially the chloramines, are either off-gassed or filtered out.
Another great option in some sprayers is the ability to spray out rock dusts such as Azomite powder, which can provide your trees with valuable trace elements and minerals (get it? The A to Z Of MInerals and Trace Elements = the name AZOMITE)
Rates?
You can add about ½ ounce of fish emulsion (about two tablespoons) to 1 gallon of water and spray up to twice per week. Here is an excellent third-party link about fish fertilizers, emulsions, and foliar spraying.
Microbes
EM
If you want to work with stable microbes, the best option is to use Effective Microorganisms (EM). We provide them at Austin area Farmers' Markets for $5/quart. A solution of 1% is recommended. You can apply them once weekly during the growing season, preferably in the evening when the sun won’t burn the leaves. During wet periods, you can increase that to 1-3 times per week. Surfactants or wetting agents can help. Click here for our EM product.
Whey
Whole Milk Whey and, even better, raw milk whey or the whey from raw milk kefir can be very effective with good soils. I have seen articles written for farmers recommending rates of about 1 gallon per acre. That means diluting the milk in high-quality water.
Compost Tea
Check out your favorite garden center to see if they are brewing compost tea for their own use. It was much more common to find local garden centers brewing compost tea back in the period 2008-2014.
Granulated minerals and soil supplements
Another great application for some tools that can do the job, is to place granulated minerals (see Azomite pelleted) into the hopper and broadcast the pellets in an distribution over your land. You can lob the minerals 30' out in any direction from where you are standing. It's like spraying painting for your soils. I know that you can do that with the Stihl SR-450, but check with the other models to be sure.
Pest Control
Sometimes, the bugs can get out of hand. A simple application of Diametaceous Earth can be the answer in a number of cases. These sprayers are able to provide a fine coating of DE dust to the soil and plant surfaces. Watch out however, that you can go overboard with this strategy. It can be like putting out an A-bomb and reverberating through your soil and plant’s microbial kingdom. Best to apply this strategy multiple times in small doses/areas rather than everywhere all at once.
Limitations
Microbes are crucial to the functioning of our plants, our soils, and our human bodies. It is one of the reasons that we named our farming company Microbial Earth Farms. However, important lessons have been learned about the use of microbes. If your soil is out of balance regarding nutrients, the microbes will only be able to perform as well as the limiting step. Thus a soil test is important for addressing those bottlenecks. In addition to minerals, you need to feed your soil carbon and nitrogen.
If you want to know more about soil testing, sign up for our newsletter at the bottom of this page. We will be blogging more about this in the coming weeks.
Compost
Compost is an excellent addition to your soils, but it will pay for you to become a #soilsnob and seek out quality. The long-term impacts of feeding cheap food to your soil are trees that collapse during stress events, and those events are growing more frequent now. One Rth produces a very high-quality compost using quail droppings high in nitrogen (non-CAFO and non-GMO feed, unlike the vast majority of composts from the waste of the biggest CAFOs).
Climate Smart Compost
Some of the newest thinking about compost involves using the above-mentioned probiotics (EM) as an accelerant in the compost pile. The probiotics can significantly reduce the amount of methane produced by the compost pile. But where does that nitrogen go if it is not becoming methane? That is where the addition of biochar comes into play. If introduced into microbially active composts, the biochar can mop up surplus nutrients as well as provide very long-term housing for the microbes. The resulting compost is worth much more than the stuff that quickly degrades and leaves you needing to buy more from the store. Biochar is effective as a storage structure for the very long term (i.e., longer than humans live). #soilsnob type composts should be seen more as capital improvements to the soil rather than an expense. Like regenerative agriculture, residential soil owners must move on from the chemical party of the past.
Mulch
All of those dead limbs and wood chips have to go somewhere. Get ready for an abundance of offers for mulch. Whether you can get someone to deliver is another question, but the coming spring should be an excellent time to protect your trees with mulch, and, just as importantly the microbes around the roots of your trees.
Remember, the microbes transition your soil’s nutrients into the food the roots can consume.
Micro-Livestock
Finally, you might want to consider the role of micro-livestock on your property. OneRth is developing some new thinking about how we design the penning to capture the nitrogen benefits of manures and enable micro livestock (quail, rabbits, chickens) to exercise their ecosystem services, such as improving our soil fertility. We need to start seeing micro livestock first as tools for improving our environment, not as the source of eggs or meat with messy droppings.
