Plant Growth Regulator for Spruce Trees
Spruce trees are among the trees that I receive the most calls about from concerned customers. These trees are not “native” to southeast Nebraska soils, and as such they suffer from a pair of funguses (rhizosphaera needlecast fungus and cytospora fungus in bark tissue) due to nutritional stress. The fundamental “problem” is that while the soil contains the needed nutrients, Lincoln soil is too alkaline, which results in poor uptake at the root membrane level. Organic and safe copper spraying of the canopy to control the needlecast fungus in April is appropriate for all high value spruce since this is a universal phenomenon. The bark fungus, which is identifiable as globs of crystalline sap accumulating in masses on the stem, is not “directly” manageable by chemical means. Degradation of tree vitality does not happen in one season, these stresses build over a period of years.
All remedies are also are “slow acting,” and help the tree when applied as a program over a period of years. The first and easiest remedies are to make sure your trees are getting enough moisture during the occasional warm and dry period in the middle of winter: early spring of 2022 was and extreme example. Naturally, this can be difficult since your hoses and faucets are typically not ready to use in the winter months. “Evergreen” refers to the fact that spruce hold their “leaves” year round. As such they are subject to moisture loss (dessication) when the ground is thawed during, for instance, a February warmup. Secondly, an acidic fertilizer can be added to the root zone of spruce trees. “Jobe’s Evergreen Fertilizer Spikes (part number 02611)” can be used and are available at Earl May or on Amazon. https://www.amazon.com/Jobes-Shrub-Fertilizer-Spikes-Clear/dp/B001OTR1OE/ref=sr_1_1?crid=1JPHSCK3KCSN2&keywords=jobes+root+feeder&qid=1660575218&sprefix=jobes+root+feeder%2Caps%2C98&sr=8-1 Larger trees under extreme stress are deserving of faster acting liquid fetilzer application using a root feeder. In either case, it’s important to use an “acidic” variation of fertilizer, since we are trying to alter the too-alkaline clay soil that is on top of Southeast Nebraska’s limestone bedrock.
With the above fundamentals out of the way, it is now fair for me to introduce the latest trick to help spruce offered by modern science: Spruce trees are among the several species that are excellent candidates for growth regulator application (chemical name “paclobutrazol”) marketed as Cambistat. ® This product is injected into the soil at the base of your tree once every three years. As the name implies, it does slow the growth of your spruce slightly, which can be a benefit for trees or shrubs that are already too big or up against a fence or walkway. The real magic is what is happening instead when the energy of the tree is tricked at the hormone level into stimulating more root growth. It is here where fine root densidty is stimulated, and this helps to improve the poor nutrient absorption which predisposes the tree to the previously mentioned fungal stresses. While the public should be wary of claims that a new “magic potion” is worthy of their expense, I’m suggesting that this is exactly the case with respect to plant growth regulators.
In the interest providing the “complete picture” with regards to management of stress in evergreens, in closing it is appropriate to discuss one other methodology which is gaining popularity. I want you to have an idea of the “complete” picture when considering plant healthcare options for the future, soas to avoid “changes of heart” or the disappointment of realizing later that your money should have been spent in a different manner. In the coming years I hope to offfer “Air Spade service.” This involves a wand that blasts air in the soil under your tree to remove the soil surrounding your trees roots without damaging the roots. The old soil is hauled away and an ammended soil takes its place. This is the current gold standard in plant health care and it comes with a hefty price which will limit its applicaton compared to the above methods.
Please call or text anytime with your questions regarding plant growth regulator for your spruce trees.
Will Frerichs, 402-476-0499
