Learning Centre
Want to learn more about groundworks and how to take care of your greenery better? Peruse some of our learning topics, based on Ken’s expertise and learn more.
Grubs
Grubs – they’re almost as ugly as the damage they cause. These pests are so sneaky it’s often difficult to even know they’re doing damage until it’s too late. Worse yet, they usually pick the most lush lawns to feast on.
Grubs are actually larvae of beetles. Most are off-white with brown heads, and known by the “C” position they take when disturbed. Grubs over winter bury underground and begin feeding on turf roots during the spring and summer.
Grub feeding leaves irregular brown patches and the lawn may have a spongy feel. Sod will roll up like loose carpet if the roots are already destroyed. The only way to know for sure, though, is to gently pull up a small section of sod. If you see more than four grubs per square foot, you have a problem. Lawns with severe grubs can have 40 – 60 per square foot.
There are numerous treatments to combat grubs. However a new treatment, imidacloprid (one brand is Merit), takes a new approach to grub control. The treatment is applied to soil and is taken up by plant roots, making the plant the toxic substance. It doesn’t harm the grass, you, or other plants, but it turns your lawn itself into a deadly choice for hungry grubs. Imidacloprid is 90-95% effective, it lasts longer and it requires a lower dosage than other types of traditional grub treatments. Imidacloprid must be applied early in the season before the grubs become active to allow for the plant to absorb the chemical. Imidacloprid also has a residual factor of up to 4 months, so frequent reapplications are not necessary, however depending upon your season, you may have to reapply imidacloprid for seasonal grub control.
For those who are environmentally concerned, here is a friendly approach to fighting grubs which is through the use of beneficial nematodes. Nematodes are very small worms found naturally in our soil and other habitats. How do nematodes kill grubs? Nematodes in their immature infective stage, search, find and kill insects. Nematodes then grow and multiply inside the insect. Nematodes enter an insect and release their own unique bacteria that infect and kill the insect in 36 to 48 hours. The nematodes then reproduce, resulting in more grub snatchers for the lawn and garden!
Though nematodes can be an effective and safe pest management options, there are limitations to their use. The first is related to their manufacture and storage. It is difficult to synchronize the development of infective juveniles under laboratory conditions. Also, the nematodes must be shipped in the proper media and stored at the correct temperature. So, it is a good practice to purchase nematodes from reputable manufacturers (many guarantee the count) and to check the percent viability of a package of nematodes before applying them. This can be done by placing a small amount of nematode-containing material in water and observing the live nematodes under a microscope or hand lens.
The other factors to consider relate to their actual usage. In order to ensure maximum effectiveness, it is crucial to apply them at the optimum environmental conditions needed for their survival. It is best to irrigate the target site, both before and after application, because nematodes need moist conditions to prevent dehydration and aid with movement to find hosts. Also, the best results are obtained when the relative humidity is high, ambient temperature is neither extremely hot or cold, soil temperature is between 55o and 90oF, soil is moist and direct sunlight is minimal. All of these factors help prevent the nematodes from drying out and increase their survival.
Root feeding
Your trees and shrubs are a growing investment that should increase in beauty and value with each passing season. But often, landscape plants fail to flourish and may even go into decline due to lack of proper nourishment.
Proper feeding of your ornamentals offers many benefits, including improved flowering, increased resistance to disease, and increased ability to ward off insect attacks.
Root feeding injects the proper plant foods directly into the root zone of the plants, which allows the fertilizer to be easily absorbed and quickly put to work.
Feeding helps compensate for poor soil or less than ideal planting locations. Over time, poorly located plants may gradually “decline” if not given proper care.
Feeding your trees and shrubs at least once per season is good preventive maintenance. The right diet helps to prevent many types of stress that weaken plants. When your trees and shrubs are in top health and are growing well, they’re often strong enough to fight off many infectious diseases or insect attacks without serious or permanent damage.
Balanced root feeding, scheduled on a regular basis, helps to improve and protect your growing landscape investment.
Slide Seeding
When thatch builds up to over one half inch, it begins to interfere with the healthy growth of your lawn. A thin, sickly lawn is often the result.
Older or neglected lawns may become infested with many varieties of unwanted grass which should be removed and replaced.
Serious disease or insect damage can also thin a lawn so badly that renovation is the only answer.
Lawns that are planted with grasses that require much water may need to be converted to more drought-tolerant types. For all of the cases above slice seeding is one of your best and most economical solutions.
A slice seeder is made up of three basic parts:
- slicing knives that cut through the thatch and into the soil, creating furrows and mixing soil with the thatch,
- seed tubes which place the seed into the prepared furrows, and
- disks or rollers that close the soil over the seed.
Slice-seeding provides proper seed-to-soil contact and results in much better germination and growth rates than seed that a broadcast or spread by hand.
Lime
When your soil pH is too low (acid) it needs lime to bring it back into balance. Soil that is too acid causes “fertilizer lock-up”.
This means that fertilizer and important micro-nutrients become locked up in the soil and unavailable to the grass plants.
A lawn in this condition is called “unthrifty” because even when properly fertilized, it can’t make use of the plant food applied to become thick and stay green. We suggest annual liming for acid soils. It helps everything else work even better. That’s what makes lime such a great lawn value for you.
It is recommended that lime be applied in the fall to enable the material to break down over the winter for the next season’s growth. However, lime can be applied any time. If a soil test in the spring indicates lime is needed, apply it at once. Lime begins to react immediately and reduces acidity and improves turf growth through the summer and fall. However, if urea fertilizer is used, apply it three weeks before the lime to permit the urea to react with the soil. If urea is applied at the same time as lime, nitrogen will be lost due to the increased pH around the fertilizer granules.
Lime is safe to use! The common forms of lime applied to turf – calcitic lime and dolomitic lime – are non-toxic to humans or grass and will not cause pollution problems.
An application to bring the soil pH to 6.5 should last four to six years, depending upon your area. Soils tend to revert to their natural acidity levels, and most nitrogen fertilizers used on lawns are acid-forming, gradually decreasing the soil pH. Ammonium nitrate and urea, two commonly used nitrogen fertilizers, break down in the soil to produce nitric acid. Approximately 1 3/4 lbs. of pure lime is needed to neutralize the acidity caused by 1 lb. of nitrogen from either of these fertilizers. In a yearly fertilization program where a total of 4 lbs. of nitrogen is applied per 1000 sq. ft., approximately 7 1/4 lbs. of pure lime would be needed to neutralize the acidity the nitrogen fertilizer produces. You should test the soil periodically and apply lime when needed.
Lime materials available for purchase are calcitic lime, dolomitic lime, burned lime, hydrated lime, marl, and pelletized lime. However, not all of these are appropriate for use on established lawns.
Calcitic lime is mined from natural, limestone bedrock deposits. The soil is bulldozed off the bedrock; holes are drilled in the limestone, then it is blasted out with dynamite charges. It is crushed to about 1-inch stones, then pulverized or ground to screening specifications. Calcitic lime, also called aglime, has a neutralizing value between 85-100 percent. In addition to neutralizing soil acidity, calcitic limestone supplies calcium, an essential element for plant growth.
Dolomitic lime is mined in a manner similar to calcitic lime. It has a neutralizing value between 85-109 percent and supplies both calcium and magnesium for plant growth.
Burned lime (calcium oxide) is also called quicklime or unslaked lime and is manufactured by roasting crushed lime in a furnace to drive off carbon dioxide. It has a neutralizing value between 150-175 percent, which is the highest of all liming materials. It is a powdery, caustic material that is difficult to handle because it absorbs water very quickly. When applied, use only on the soil surface and incorporate immediately to prevent the formation of granules or flakes which decompose slowly.
Hydrated lime (calcium hydroxide), also called builder’s lime or slaked lime, is manufactured by adding water to burned lime. It has a neutralizing value of between 120-135 percent. Hydrated lime is a caustic, powdery material and should not be applied to established turf since it can burn.
Marl is mined from deposits that lie below peat bogs. It is calcium carbonate material that was formed by shell deposits or produced in aquatic plants. The material, deposited along with clay and organic debris, is somewhat impure, and has a neutralizing value between 70-90 percent.
Pelletized lime is finely ground agricultural lime to which a cementing agent has been added to form “pellets.” It has been in use for several years, and while it is more expensive, this material is easier to spread than regular liming materials and eliminates the dust problem commonly associated with them. The lime pellets dissolve with a soaking rain or irrigation. If pelletized lime is used for establishing new lawns, apply to the soil surface and water thoroughly before tilling. If intact pellets are incorporated, neutralization will be confined to pockets within the tilled soil since lime moves very slowly in soil.
Lawn Disease
Of all the pests that damage lawns, fungus diseases are one of the most difficult to tame. There are hundreds of diseases that can infect your turf.
Some are relatively harmless, others can destroy an entire lawn in a very short time.
Fungus spores spread on the wheels of lawn mowers, on the shoes of children, on the droplets of rain that bounce from plant to plant during rain or watering, or blow like microscopic seeds across your lawn. Every lawn has disease organisms. The trick is not letting them get the upper hand.
To reduce disease, keep the lawn healthy and growing with proper feeding, mowing, watering, and thatch control measures. Some grass types are much less susceptible to fungus attack. Consider planting disease-resistant varieties when you seed.
Disease treatments do not usually eliminate the disease from the lawn. Instead, they suppress activity for a period of a few days to several weeks. The goal is to keep the disease in check long enough for the grass to recover or the weather conditions to change. Often, several treatments are needed.