If you are one of the unlucky few this summer season that has discovered grub related lawn damage than please read on. Everyone loves a beautiful healthy lawn that makes a property stand out, but you should know that your lawn can be destroyed in just a few days if white grubs (in particular) are allowed to feed freely on your lawn’s root zone. Grubs are the larval stage (four stages of development = egg, larva, pupa and adult) of various scarab/flying beetles that call your lawn and landscape home. The main beetle varieties found in Northern Illinois are the masked chafer and Japanese beetle. Several other beetle varieties include Asiatic garden beetle, European chafer, green June beetle, May and June beetles and Oriental beetle. Grubs can be described as dirty white colored, soft bodied, and robust with a brown head and six well-developed legs, with exception of green June beetle grubs, which do not have well developed legs. When the turf is lifted to expose the grubs, they usually will be lying on their sides in a C-shaped position. The life cycles of the above mentioned beetles are completed in 12 months with the exception of the common May or June beetle, which has a three-year life cycle. Adult beetles lay eggs in the ground during the summer. As soon as grubs hatch, they start feeding on the lawn roots until cold weather drives them two to eight inches deeper into the soil where they overwinter. As temperatures warm in the spring, the grubs move up from the lower soil regions and resume feeding near the surface until they become mature and pupate from May through early-June. Later emergence can occur and is dependent on local weather conditions. Heavy white grub infestations can destroy grass roots, causing the affected area to become spongy, which allows the sod to be rolled back like a piece of carpet. Even though grub infestations are not always obvious, damage is routinely discovered in spring (April or May) and late summer and fall (September and October). When you see grub eating skunks, raccoon’s or crows in your yard you need to inspect your lawn to see if grub populations are beyond 5-10 grubs per square foot. Please keep in mind that grubs do not typically appear in shade lawns. Since adult beetles usually lay eggs in full-sun green lawn areas with adequate moisture, if your lawn is dry, dormant and/or poorly rooted you will have little risk of grub damage. It is highly recommended to prevent grub damage by applying a preventative insecticide such as Imidacloprid (Merit) between late June and the beginning of August seasonally. However, if no preventative insecticide is applied and a grub outbreak is discovered than a curative insecticide like Trichlorfon (Dylox) is highly recommended to prevent large scale turf damage. If significant grub damage has occurred, the lawn will need some renovation work in early fall or the following spring to rebuild lawn density. If you suspect your lawn has grubs, please contact Pacocha Landscaping Services, Inc. to schedule an on-site visit to have our team professionally analyze your lawn and offer control and repair recommendations for your review.
The challenge we turf grass managers face every spring season (in particular) is that in order to prevent the annual unwanted grassy weed called crabgrass from growing in a lawn we either need to maintain great turf grass density to stop undesirable crabgrass (seed) from ever germinating in open soil or we need to apply a preventative herbicide to create a short lasting “barrier” that will stop any/all crabgrass seed from growing or fully maturing. Even when we have decent overall lawn density and have applied a pre-emergent crabgrass herbicide there is still a strong possibility that crabgrass will grow in weakened lawn areas like those found in heavily compacted soil areas, lawn areas cut too short (usually along curbs, roads, walks, base of trees, etc.), areas that are exposed to extreme heat for long periods of time or lawn areas that were simply left bare (not repaired) from growing seasons past.
When a granular pre-emergent crabgrass herbicide is applied it will generally provide between 6-10 weeks of crabgrass protection. The life of this synthetic “crabgrass barrier” is dependent on the amount of rain or irrigation following the application and the amount of possible soil disturbance that takes place (post application). The lower the amount of soil surface disturbance or lessor water applied will extend the life and effectiveness of a crabgrass pre-emergent herbicide application.
No grass seed should ever be planted in a lawn that recently had a pre-emergent crabgrass herbicide applied (+/- 6-10 weeks post application).
The majority of crabgrass pre-emergent herbicides will not allow desirable grass seed to germinate over the course of its effective 6-10 week life span. The crabgrass herbicide has no way to distinguish between unwanted crabgrass seed and desirable grass seed. We highly recommend applying a crabgrass pre-emergent herbicide in the spring and planting grass seed mid-August through September especially in full sun exposed lawn areas where crabgrass is more prevalent.
Lawn renovation is the process of rebuilding your lawn’s density by mechanical and manual means. To begin we normally core aerate all lawn areas to relieve soil compaction and allow for improved air-water-nutrient flow to the existing lawn’s root system. After all lawn areas have been aerated, we will mechanically slit-seed across all existing thin/stressed lawn areas. Mechanical slit-seeding is the process of planting site specific premium grass seed directly into the soil by slicing through a weakened stand of turf grass. This service ensures great seed to soil contact which translates into excellent germination rates. After all existing lawn areas have been mechanically slit-seeded, we will apply a granular seed starter fertilizer that is especially high in phosphorus to all lawn areas to further enhance the seed germination process. Next we will repair all remaining completely bare (little or no grass) areas by delivering and installing additional top soil (1/2”- 1”), plant premium grass seed and install seed germination blanket or peat moss covering to complete the bare area repairs. The absolute best time (in my opinion) to perform these services will be from mid-August through September. Actually, it is only during this time of the growing season that we have optimum seed growing conditions (warm soil temperatures, less weed competition, little chance of frost or freezing temperatures, adequate natural rainfall and cooling temperatures). The spring season will be the next best time of the year to renovate a lawn, especially for lawns partially covered by shade tree canopies. It is only in the spring season that trees have not yet fully grown their leaves and greater seed germination/plant vigor can be derived from this short term abundant sun light. Lawn renovation services in addition to properly scheduled mechanical maintenance, lawn fertilization, weed control and insect management will greatly enhance any failing stand of turf grass over a short period of time.