There is always more to learn in the world of home gardening and horticulture at large. I’m going to test your knowledge with the latest batch of grower’s terms. Chances are some will be familiar, others will be new, and some you will know precisely what is being referenced.
Do you know what these words mean as they pertain to our yardscapes and gardening craft? They are: noxious, invasive, degree day, vector, systemic, graft union and cold frame.
• Noxious – This is not a term to describe the people in your life who are irritating or that loud, interrupting talk show host. The term noxious is usually referring to a classification of weeds. While we may think that all weeds are obnoxious and troubling, noxious weeds are harmful or injurious and have been designated by an agricultural authority as being highly detrimental to crops, livestock, people, or natural habitats. Some of these types of weeds were accidentally introduced by earlier generations or transported inadvertently as part of grain shipments and have characteristics that allow them to displace naturalized and locally adapted beneficial species.
• Invasive – This, too, is generally used to describe plants, trees and even some organisms that rapidly take over an area and displace other natural or planted varieties. Many noxious weeds are highly invasive, but not all invasive plants are classified as noxious. In addition, there are various degrees of invasiveness. A plant may by described as being mildly or moderately invasive. Once we know that a plant possesses invasive qualities, we can decide if we want to include it in our gardening plots and gauge the amount of effort it will take to control it.
For instance, larkspur is beautiful, but will spread readily if a large amount of its early spring seedlings are not removed. Mints will rapidly grow into adjacent areas if they are not contained effectively. Some ground covers can become invasive, with the trade-off being that open ground is covered, more greenery is created, and weeds are better controlled.
• Degree Day – There are different types of degree days, but we’ll focus on the one that pertains to agriculture. More accurately called a growing degree day (GDD), this is a measure of heat accumulation that can be used to predict such things as the time when a flower will bloom, an insect will emerge from dormancy, or a crop will reach maturity. Since there are differences in temperature from year to year, GDDs provide a method to predict when key events are highly likely to occur, including when certain insects will hatch, when it’s best to apply pesticides or fertilizers, when certain weeds will germinate, or when it’s likely a crop will be ready to harvest.
• Vector – When we gardeners use this term, we are referring to any means that an infectious disease or organism is transmitted or brought to another living organism. An insect that carries a virus and then transmits it by piercing the surface of a plant is said to be the vector that brought that virus to the plant. The same term is used in diseases that can affect humans. For instance, the common brown tick is a common vector for Lyme’s disease. Knowing what vectors have negative consequences for our gardening efforts allow us to intelligently work to control pests and hosts that can bring disease to our crops.
• Systemic – This term is usually heard in conjunction with insecticides or pesticides. These types of substances are water soluble, and can be readily absorbed by a plant or tree where it will move around in the majority of its tissues. For instance, I use a water-based systemic pesticide to drench the soil at the base of ash trees. The substance is taken up by the trees and moved to their tissues, where the pesticide protects the tree from highly destructive borers. If we are talking about plant diseases themselves, systemic symptoms are those that are involving either the majority or all of the plant, such as yellowing, stunting or wilting. This would be in contrast to localized symptoms such as leaf spots or cankers.
• Graft Union – This sounds like some association of dishonest business people or officials. In reality, this simply is the location of where tissues (a scion, stem or bud) were grafted to a desired rootstock. Many fruit and ornamental trees are grafted varieties. This allows rootstocks to be used that have desirable characteristics (such as anchorage, resistance to disease, dwarfing characteristics to highly influence tree size, ability to thrive in a local soil condition) while growing a specific variety of fruit or ornamental.
The graft union is usually quite visible due to a slight direction or color change. Generally speaking, the tree is planted with the graph union right at soil level. This helps the rootstock to focus its energy in root development and supplying resources to the top growth, while minimizing the tendency for the roots to “sucker” and create competing top growth (which rarely will have desirable fruiting or vegetative characteristics).
• Cold Frame – Seed starting time will be upon us shortly, and a cold frame is an important tool to assure that the seedlings we start make it successfully from under grow lights and warmer areas to the outdoors. Plants will do much better if there is a period of acclimation, and a cold frame provides that transition space. A cold frame is not refrigerated as its name could imply; rather it is an unheated but protected growing space used to moderate the wide temperature swings that happen in late winter and early spring days. It may be a bottomless wooden box on the ground with a hinged window top that can be closed overnight to retain heat, but opened during the day. Mine is a series of hay bales with a moveable plastic sheeting top and weights. When seedlings are the right maturity, they are moved into the cold frame to harden off (acclimate) before they are planted.
Before we end this week’s column, mark your calendar for a couple of great gardening events. First, the annual Spring Expo is almost here. It will be held on Saturday, Feb. 24 at 10 a.m. There are several great classes and workshops being offered, as well as a presentation by Kevin Shields, landscape architect for the LDS Church. The cost is only $5. Watch for more information on class offerings online, and elsewhere in the Tooele Transcript Bulletin, as we get closer to the event.
The Master Gardeners will also be hosting a free public presentation on seed starting. If you want to have a productive garden faster when the warmth settles in for the season, there is no substitute for starting plants early. There’s both technique and art to it, and you can learn how to succeed by coming to the class on Wednesday, Feb. 28 from 7-8 p.m. at the USU Extension Offices at 151 N. Main St., Tooele.
In the meantime, be patient. We are fully in the middle of sucker weather. There will be fits of cold and freezing before real warmth settles in. But before you know it, we’ll be in the full swing of gardening again.
Jay Cooper can be contacted at firstname.lastname@example.org, or you can visit his channel at youtube.com/dirtfarmerjay for videos on the hands-on life of gardening, shop and home skills, culinary arts and landscaping.