Lawn Doctor Our Service

advice

Subjects covered : Drought Stressed Lawns / Watering / Mowing / Red Thread

Drought stressed lawns

Information:

Turf grass is a plant that consists of approx. 85% water and 15% dry matter, therefore irrigation or application of water is fundamental to survival and growth. The soil acts as the reservoir , supplying the major proportion of this water to the plant. The UK has just experienced the 2nd driest Winter / Spring for the last 100 years.

During dry periods the soil has a tendency to dry out, and without water the turf grass will enter into a period of dormancy and will eventually deteriorate leaving the lawn brown and disheveled, if no action is taken.

There are several things that can be done to reduce the problem :

Raise the cutting height on your mower to 11/2 inches .This will reduce drought stress in your lawn and help to reduce loss of water by evaporation.
Water your lawn : Not in the heat of the day , either the morning or evening , water the lawn during dry periods every 2/3 days ( little and often can encourage shallow rooting making the plant susceptible to drought stress
Water your lawn : for 20-30 minutes each time .This will ensure the water gets deep into the soil and will encourage a deep rooted , more drought resistant plant.
Application of a wetting agent/ penetrate . This can be applied with other treatments to heavily drought stricken turf, and will allow dry soils to hold water better , thereby assisting in the recovery of your lawn.

Watering your Lawn

Information:

During the summer months there is often less natural rainfall than your lawn needs to be healthy and to look its best. Irrigation is one of the most important things you can do to ensure a healthy and green lawn.

The average lawn consumes about 1" (25mm) of water per week. When there is not enough rain to meet this need, watering is the answer to keep the plant green and healthy and to encourage deep root growth.

Soil type and the landscape can dictate how often and how long you need to water, i.e. sandy soils absorb water fast but lose it just as quickly and may need more than 1” per week. Clay soil holds water and dries out slower and is difficult to irrigate because it absorbs water slowly and runoff is a real concern. Loamy soil is ideal for grass. It has the necessary organic materials and nutrients and can absorb water well and release it to the roots extremely well.

The landscape can affect irrigation practices. If the lawn undulates or slopes water may tend to runoff, or to pool in low areas. When watering, you need take into consideration these factors and compensate accordingly. Dry or brown patches of grass indicate that water is not penetrating to the root zone and steps should be taken to improve that penetration.

How much to water:

It is recommended that you water your lawn twice a week and that you apply at least ½” at a time. Place some plastic containers on the lawn and measure the amount of water you are applying to see how long it takes for your system to apply ½”. With this plan you would water twice during a week to achieve the 1” goal. A ½” of water will penetrate into the soil and will encourage roots to grow down – more than ½” is even better. Less than ½” of water will stay at the top of the soil and will actually encourage roots to stay very shallow or even grow up to get to the water. This will result in weak grass plants with very little resilience. Frequent, light watering can result in the formation of an undesirable thatch layer on top of the soil.

When to water:

The best time of the day to water your lawn is early in the morning and next best is during the day. The goal is to have the grass dry before nightfall. Lawn diseases, fungus, mould and mildew all like moist, cool and dark conditions. Watering the grass at night or leaving it wet as night falls helps to create these exact conditions – and is to be avoided if possible.

Mowing your Lawn

Information:

The first principle is mowing height. A lawn cut at the correct height has more ability to produce food for itself, will stay greener in adverse conditions, will reduce weed germination and is more resistant to diseases. Weeds and weedy-type grasses need plenty of sun and heat to sprout. Taller grass shades the soil and is one of the best weed prevention tools that can be used.

As much as possible, your grass should be at least 1 ½ inches after it has been mowed. This is not, unfortunately, a “bowling green” appearance, but it will result in a much healthier and vigorous lawn.
Mowing higher will result in taller grass with will shade the soil and will reduce water loss from evaporation.
When the grass is cut too low, most of the food producing parts of the plant (the leaves) are lost. This can result in a brownish lawn that can take weeks to recover.
Grass that is cut too short is also very susceptible to disease. Because there are not leaves the grass plant has no strength or reserve to fight off disease and is much more susceptible.

The second rule is frequency of mowing. Lawns grow at different rates from season to season and year to year. During the spring and autumn, turf produces more top growth. Your mowing schedule should match the growth of your lawn. Once a week may not be enough during periods of heavy growth, but every ten days might be fine during the summer.

The key to mowing frequency is to never remove more than 1/3 of the total blade height in a single mowing.

Type of Mower:

The best quality cut is obtained with a cylinder mower having a large number of cutting blades. This is the only type of mower that should be used on the fine grass types that make up a luxury grade lawn.

As well as cylinder mowers, rotary and hover mowers can be used on the coarse and mixed type grasses that you may find on the utility or amenity turf of a family lawn. You should also alternate your mowing pattern to avoid ruts forming which may cause compaction, poor drainage etc.

It is very important to sharpen your mower blades at least once a year. If you use a rotary mower, the blades should be sharpened at least twice a year. Dull blades do not cut the grass as much as they beat it off or tear it. This will show up, soon after mowing, as a whitish cast to the tips of the grass leaves. The whitish material is the sap of the grass which has flowed out of the broken and beaten tips of the leaf. As it dries is has a whitish appearance. A close examination will actually show this. After a day or so these same tips will have a light brownish cast as these damaged tips dry up.

Recommended Cut Heights:

For coarse and mixed grass types used in utility or amenity family type turf: In Winter, Spring and Autumn: Cut to 1 ½”. Because summer can have some hot, dry spells, the grass plant should be a bit higher in order to better handle these adverse conditions. So, in Summer cut the grass to between 1 1/2” and 2” dependent on the current weather conditions and rainfall.

For fine leaved varieties of grass that go to make up a luxury grade lawn:
In the Winter, Spring and, Autumn: Cut to ½ “. In Summer: Cut to ¾ “.

Red Thread

A fungus that lives in the turf causes Red Thread disease. Most turf has fungus of some kind in it, but normally you do not see the fungus or disease that it causes. During conditions of high humidity or wet periods, red thread may appear. In the beginning, you may notice small patches of grass leaves turning brown or pinkish in colour, starting to die on the surface. A few days later, on closer examination, you may notice red, thin threads in the pink patches. This is in fact the fungus ,fungus can also be spread by your lawn mower. Turf containing rye grass can be more susceptible, but it can be found on all species of turf grass in the U.K. , on very fine grasses Red Thread can be treated with a fungicide but in most cases is easily corrected with the right feeding regime.

Mushrooms Toad Stalls

Effected areas: All turfgrasses

Description: Heavy rains can result in the appearance of numerous slime molds and mushrooms in home lawns. Although these organisms are often spectacular in colour and size, most are relatively harmless to the plant life.

Slime molds are primitive micro organisms that can produce white, purple, orange or brown blobs or patches of fungus-like material known as sporangia (spores). They can cover turfgrass, strawberries, ornamentals, and numerous other horticultural plants. Slime mold spore masses, when mature, are powdery and break apart easily during rain or when knocked around by your shoes. The spores of the slime mold survive in soil or organic debris and germinate during wet weather to form motile swarm spores. Some of these spores fuse to become amorphous amoeba-like structures that engulf other organisms or organic matter. Slime molds can actually move or flow across soil or plant surfaces. Although unsightly, these organisms are not pathogenic to living plant material. Frequent mowing, raking, or brushing of the spore masses is usually sufficient to control the problem.

Many different mushrooms can also appear in lawns. Some of these mushrooms are associated with arc-like or circular patterns in turfgrass called fairy rings. The ring pattern is caused by the outward growth of fungal mycelium. The mycelium forms a dense, mat-like structure in the soil that decomposes organic matter. This decomposition releases nitrate into the soil, which in turn stimulates the growth of the grass at the outer portion of the ring. This results in a dark green appearance of the grass at the margin of the ring. Unfortunately, the thick fungal mat formed by the fungus does not allow for water penetration. The fungus may also release certain by products that are toxic to the turf. This can lead to dieback of the turf in the ring. Fairy rings are difficult to control. You can sometimes eliminate the ring by digging to a depth of 6 to 12 inches and 12 inches wide on both sides of the ring, refilling the hole with non-infested soil. Alternatively, you can try to mask the symptoms by fertilizing the rest of the lawn so that it is as dark green as the ring. This really isn't a good idea because it tends to promote other turf problems.

Recommendations:

Some mushrooms in lawns are not associated with fairy rings. These may be mycorrhizal (symbiotic association with tree roots) or live on dead organic matter (wood, etc.) in the soil. Since some of these mushrooms are beneficial, you don't really want to kill them. Besides, a fungicide spray to the mushroom itself does little good. Most of the fungus is below ground and inaccessible to the chemical. If the mushrooms are a nuisance, pick them and dispose of them as soon as they appear. Also remove any sources of large organic debris from the soil. Some of the mushrooms in the lawn are edible, but others are poisonous. Never eat any mushrooms unless you are sure of their identity.