A new publication for nursery growers has been released! This publication, a joint venture between Purdue University and Indiana Department of Natural Resources, informs that nursery and landscape industry about new state regulations regarding invasive plants. The rule goes into effect in two stages. As of April 18, 2019, it is illegal to introduce a plant species (from the list of 44) if it is not already in Indiana. Listed plant species already in trade will be restricted from sale one year later (April 2020). The one-year grace period is designed to reduce the economic impact on the nursery industry by allowing time to sell down existing stock and adjust production. Click here to read or download a free copy: https://www.extension.purdue.edu/extmedia/ho/ho-305-w.pdf
Archives for April 2019
Oak leaf blister is caused by the fungus Taphrina caerulescens. Infections occur as buds swell and open during wet, spring conditions. Leaf blister symptoms usually appear within several weeks following infection as 1/4-1/2 inch circular, light green bulges on the top surface of leaves.(Fig 1) From the underside, the affected areas are sunken or depressed. These distortions may cause leaf bending or curling of narrow-leaved oak species. Some insect galls may resemble symptoms of oak leaf blister at first glance. (Fig 2) Upon closer inspection, the insect gall is a solid mass of leaf tissue as opposed to the distorted leaf blister caused by Taphrina. As the blisters age, they become dry, brown spots; severely diseased leaves may drop prematurely. (Fig 3.) Although this disease is quite conspicuous, it does not seriously harm healthy trees and control with fungicides is not usually recommended.
Q: I’ve attached pictures of the only tree we have on our property. Because it is our only tree, I am deeply concerned with the possibilities of irreparable damage to it. As you can see, one of the branches broke off during a November windstorm. Unfortunately, that left a bare gap on the trunk. Please let me know how to treat this damaged area so no further damage is done to it and tell me what can be done to preserve its longevity. I do not know the name of this tree but it’s local. It is found almost everywhere in this area. It blooms white flowers in the spring that fall off shortly after and changes to beautiful colors in the fall. As you can see, it is a beautiful tree. Please help and thank you so much. – L. G., Valparaiso, Indiana A: To answer the second part of[Read More…]
We all know that plants take up nitrogen in significant quantities, compared to some of the other essential nutrients. What most don’t know is that elemental nitrogen (N) is not what is taken up by plants. In fact, nitrogen can be taken up in only two forms, ammonium (NH4) and nitrate (NO3). Fertilizer labels will list the elements contained within, including the various types of nitrogen (Fig.1). What you should know about pH….. The definition of pH is the negative logarithmic of the hydrogen-ion concentration. What does this even mean? More simply put, the more H+ (hydrogen) ions, the more acidic, while the more OH– (hydroxide) the more basic. Always remember that the pH scale is logarithmic, which means each number on the scale is 10 times more acidic or basic than the next number on the scale. A pH of 6 is 10 times more acidic than a pH[Read More…]
People with lawn equipment can accidentally damage a tree, especially young trees which can cause the tree to die.
Hakone grass (Hakonechloa macra), also known as Japanese forest grass, is often used for massing in beds in where a low maintenance ground cover is needed in semi-shaded areas. The graceful arching stems along with the availability of gold or white striped variegated cultivars make it an attractive option. There are few reports of disease problems on Hakone grass but one problem seems to show up with some regularity in both nurseries and landscape beds: gray leaf spot and blight, caused by the fungus Magnaporthe (= Pyricularia). Fig 1 and 2: Hakone grass in a landscape bed with gray leaf spot. Reports of this problem from studies done in Ohio indicate that blight found on hakone grass is caused by the same fungus that causes gray leaf spot on perennial ryegrass and fescue. Gray leaf spot on perennial ryegrass is a widespread problem in the Midwest, especially on golf course[Read More…]
The Invasive Terrestrial Plant Rule was signed by Governor Holcomb and published on March 18, 2019. The rule goes into effect 30 days after publishing, so it will be effective later in April. The rule states with respect to the 44 plant species included on the rule: “a person must not: (1) Sell, offer or grow for sale, gift, barter, exchange, or distribute a species; (2) Transport or transfer a species; or (3) Introduce a species. (4) Subdivisions (1) and (2) of this subsection are effective one year after the effective date of this rule.” Note that section (3) “Introduce a species” is effective immediately (around April 16, 2019). Selling, offering, distributing and transport doesn’t go into effect until April of 2020, so nurseries will have some time to sell down their stock. This is an important component of the rule to minimize economic loss to nurseries that grow and/or[Read More…]