Fall is prime time for lawn and garden weed management for several reasons:
Switchgrass (Panicum virgatum) is a native, warm season prairie grass that has slowly found its way into the popular ornamental grass market. This is a big plant, generally growing 3-7’ tall and probably about 3-4’ wide. The plant develops upright but spreading clumps of medium green leaves with fairly large, open, generally reddish panicles containing relatively large seeds. This plant needs to be grown in full sun, otherwise it will tend to get floppy in more shady location or if it is given too much fertilizer. The seed of the native switchgrass is fairly easy to get but one would be better off to look for one of the many cultivars that are now available. Many of these have a more upright growth habit and may also develop a nice reddish orange fall foliage color that continues on until mid-winter when the plants turn tan. The seed heads make attractive cut flowers for use fresh or dried. Plants will slowly spread by scaly rhizomes beneath the soil and will also often self-seed, but the cultivars to not come true from seed so best propagation is by division.
Though some pests migrate into the garden, many that infest your fruit and vegetables overwinter in your garden or landscape. Weed seeds can survive the cold temperatures while insects and diseases can live within plant debris or in the soil. Cleaning up the garden at the end of the season can help reduce inoculum or the number of existing pests, decreasing the chance of infection or infestation the following season.
Gardeners and homeowners who are thinking of taking a soil sample this fall or next spring need to be aware that South Dakota State University will no longer be offering commericla testing after October 22, 2011. A list of nearby state or private laboratories that can be used for garden and lawn samples is given below. The private laboratories are not necessarily recommended or endorsed. Gardeners with questions on sampel submissions, analysis charges and recommendationss hould contact the laboratory of interest.
After a flood, garden soil may not be safe for growing fruits and vegetables. Flood water may contain agricultural runoff or other chemicals, or disease causing organism from fresh manure, sewer systems or lagoons.
According to the SDSU food safety specialist, foodborne illness has been associated with garden vegetables contaminated with flood waters containing pathogenic bacteria, parasites and viruses. The most common pathogens involved in these outbreaks include E. coli 0157:H7, Cryptosporidium parvum, Cyclospora, Giardia, Campylobacter and the Hepatitis A organism. The pathogens will eventually die out, but they can remain persistent for several months.
Applying mulch to a vegetable garden can help you reduce weed competition, maintain moisture in the soil, modify soil temperatures, and create a barrier that will reduce disease infection.
Weeds are reduced because the mulch becomes a barrier that weeds cannot penetrate through. Additionally, many seeds are also less likely to germinate. Some perennial weeds may still penetrate the barrier, and will require mechanical removal, but over all labor on weeding will be reduced with this approach. Water will not evaporate as quickly and soil will not erode away as easily under mulch. Plastic mulches can be utilized to increase soil temperature and speed up plant growth in the spring. Organic mulches will keep the soils cooler in the heat of the summer. A layer of mulch will reduce the amount of soil that splashes up on plants during irrigation or a rain shower. This will reduce the incidence of disease infection.
Xeriscape comes from the root words xeric and scape. Xeric means characterized by or adapted to extremely dry habitat. This term for ‘dryland landscaping’ was established by the Denver Water company in the early 1980’s. This technique can reduce water usage, soil erosion, maintenance costs, and maintenance time. These plants will also attract butterflies, native wildlife and beneficial insects. This is an ideal technique for South Dakota’s semi-arid climate.
Drought stress symptoms in home lawns are occurring in some areas of South Dakota due to dry conditions. Brookings, for example, has received only 0.57 inches of rainfall between July 29 and August 24, but has lost about 4.7 inches of soil moisture through evapotranspiration during the same period.
Injury to cool-season turfgrasses may be severe during mid-summer to early fall when plants are stressed from high temperatures and insufficient moisture. For example, high levels of stress at this time of year often increase susceptibility to injury from certain insect pests, such as white grubs. These root-infesting larvae are the immature stages of scarab beetles. Larvae are easily recognizable, having a C-shaped, white to cream-colored body, tan to brown head, 3 pairs of legs, and transparent abdomen. At this time of year, larvae are near the surface and are actively feeding on turfgrass roots. The affected turfgrass may turn brown and die from drought stress due to the inability to take up water from loss of roots. Oftentimes, the turf can easily be picked up in large sections, exposing the feeding grubs. Additional, and perhaps greater, turf damage may be caused by animals feeding on grubs, including skunks, moles, and birds.
People often assume that Kentucky bluegrass is the best option for a lawn in this region, and though this type of turf has several ideal qualities, there are other options that may even be a better choice for your location or maintenance approach.
Kentucky bluegrass is a great choice if you live in Lead or Deadwood, SD for a full sun setting. This type of grass has underground rhizomes that allow it to form a nice sod. It has a deep green color and high wear tolerance. It will survive the cold Dakota winters and will survive drought by going dormant. This grass can be installed as seed or sod. There are new cultivars that will tolerate shade and hybrid bluegrass (a cross of Kentucky and Texas bluegrass) that is more drought tolerant. Disadvantages include thatch formation, susceptibility to disease and insects, poor salt tolerance and a higher nitrogen requirement.
Many riverside communities are experience flooding and many homes and families have been directly impacted by this event. Once the water recedes people are going to be inspecting and repairing their home. Homeowners will also need to inspect their trees for symptoms of flood injury.
Summer flooding is of a particularly concern with respect to trees. Trees are actively growing during the summer months so the impact of summer flooding is quite different from winter or spring floods. While most people are aware of photosynthesis, the process where trees “take in the bad air (CO2) and give back the good air (O2)” most are unaware that living tree tissue is also respiring, essentially taking in the good air (O2) and giving off the bad air (CO2). This also applies to roots and during the growing season roots have a surprisingly high oxygen demand. If trees are standing in water during the growing season, tree root systems will begin to decline as there is not enough soil oxygen to support growth. As the roots die, the tree’s ability to absorb water decreases and the foliage begins to wilt. Paradoxically the tree dies from the lack of water because it is standing in water, a phenomenon referred to as physiological drought.
While everyone is enduring the summer heat, the first hint of cool fall weather is probably only a few weeks away and with that the fall planting season will begin. Container and balled-and-burlapped trees can be planted throughout the growing season but usually the combination of cooler weather and warm soils in the fall allows for newly planted trees to quickly adapt to their new home. Surprisingly one of the best times to plant many evergreen trees is around Labor Day.