Lawn care

1. Lawn care in each season

Spring

As soon as the topsoil layer dries, the essential tasks can be commenced, which shall awaken the lawn from its winter slumber. Begin with a thorough clean-up of the lawn’s surface, which is tied in with further expedient measures:

• Remove all fallen or windblown leaves, branches, and, if need be, stones
• With a sharp rake (or even better, a scarifying rake), rake up or scarify the existing sod to a depth of 3–5 mm. This aerates the lawn and removes moss and emerging felt – the lawn is as if newborn. A lawnmower can then be used on the piled up matter. The collected matter can then be composted.
• Yellowing or browning lawn growth is the result of major soil hardening or an over-watered or otherwise unsatisfactory condition, or sometimes even the work of a fungus disease. In that case, aerification must be applied by evenly distributing highly silicate sand on the lawn (1000g per 1m2)
  
• One must also not forget the proper nourishment of grass sod, which is best applied as fully combined fertilizer (30 g per 1m2). Keep in mind that large amounts of mowing during the growing season drain many nutrients out of the soil, which must be added back to the soil and be periodically maintained to ensure the lawn’s successful growth. For the rapid regeneration of damaged grass, small doses of calcium nitrate can regularly be scattered (10g per 1m2).

• In cases where some areas of the lawn are heavily damaged, it is a good idea to sow some grass mixture used for establishing lawns or the RENEWAL grass mixture (25 g per 1m2), which will rapidly fill out damaged lawn areas.
• Lawns which are over 50% damaged are best renewed as a whole.
• At the end of spring, take chemical or mechanical action against broad-leaved weeds, which definitely do not belong in decorative or heavy-duty lawns.

Summer

The treatment of existing lawns consists primarily of several minor measures that must be carried out timely and accurately. Particularly in July and August, in the full summer period, which tests the quality of an established lawn and the care that one puts into it.Lawns established in the spring should be treated very gently until they have thoroughly taken root. All lawns should be mowed in appropriate intervals according to the purpose for which the lawn is grown, as well as according to the speed of overgrowth. One should stick to the rule that the grass should be shortened by one-third in temperatures exceeding 25°C; by one-half in temperatures between 20 and 25°C. In temperatures below 20°C, one can cut off as much as two-thirds. Otherwise, in the harsh sunlight, one can be sure that the lawn will begin turning yellow, thin out, and generally become an unpleasant sight.

The lawn must never start to dry out and wither. In such cases, the lawn must be watered in larger doses, best at the rate of 20 mm/m2 every three or four days, or every day in smaller doses in the early morning or after sunset. Never water the lawn in full sunlight – this will give the grass a bad sunburn, and cause fungus and mould to develop rapidly, which will markedly damage the grass.

In order to maintain the lawn’s fresh green look and replenish nutrients drained by mowing, fertilize grass areas with nitrogen fertilizer in 14 to 20-day intervals. Only establish a new lawn in July or August on the condition that effective irrigation is at hand, since the area sown must not be allowed to dry out. Water with a fine sprinkler continuously from the time of sowing until the grass emerges.

Autumn

The autumn months facilitate, or rather require, the entire system of lawn care measures, since it is a very good time to establish lawns as well as to conduct further regenerative measures. The goal is not only to improve the lawn, but also to prepare it for winter hibernation.

At the beginning of autumn, it is a good idea to repeat the measures taken in the spring, such as scarifying, or even aerification if needed. One must also not forget the proper nourishment of grass sod, which is best when applied as fully combined fertilizer, since frequent mowing in the previous season has depleted the soil of a large portion of its nutrients. It is necessary to re-add these nutrients to the soil for lawn growth in the autumn and for the grass’ successful winter hibernation. If one still wants to correct undesirable soil reactions with calcium (a pH level between 5.5 and 6.5 is optimal), use ground limestone, or, even better, dolomite limestone, which contains the most magnesium. Never put calcium and fertilizer on at the same time, and also do not mix calcium fertilizer with industrial fertilizer. For the rapid regeneration of damaged grass, small doses of calcium nitrate can regularly be scattered (10g per m2).

In view of the biological development of weeds, autumn is just the time to liquidate and suppress them. Dicotyledonous weeds don’t look good in the grass and serve no purpose – they only deprive the grass of water and nutrients, and will gradually start to drive the grass out. Therefore, treat grassy areas with commonly accessible chemicals. If there are heavily damaged areas in your lawn, it would do good to sow it with grass mixtures for the establishment of new lawns or the RENEWAL grass mixture. New lawns can still be established as late as the end of October, since the rapidly cooling temperature will make the grass emerge in the spring of the following year. Depending on weather conditions, one can mow the grass for the last time in November when autumn leaves and other organic remains are raked up and removed. If mice appear, wait for dry weather and put poison traps in any holes. Before the arrival of winter, it is possible to spread a layer of ripe compost on the lawn, which helps level the surface off and improves the lawn’s nutrient content.

Winter

Lawns should be moderately overgrown during winter. Waste (dead grass) must be removed from the lawn by the onset of winter. Otherwise, there is a risk of major fungal diseases during winter’s course. During the seasonal frosts without snow cover, do not walk on the lawn or put pressure on it, since this can seriously damage the grass. Likewise, do not walk on the grass during thaws, since walking on the softened earth will make it uneven.

2. The Principles of Lawn Establishment

Soil Preparation

The preparation of the soil is important for establishing a good foundation. Remove stones and other undesired objects and smooth out the area so that the soil can be properly loosened and dug up to a depth of 12–15 cm. If need be, the soil can be loosened up moderately with fine sand. Apply spare fertilizer with phosphorous and potassium to the soil profile. In preliminary preparation likewise dispense the nutrients (NPK) in doses of 30–50g/m2. When weeds subsequently emerge, clear them all away from the area either mechanically or with chemicals. Repeat this step if weeds appear again.

Sowing the Seeds

The appropriate selection of grass mixtures determines the qualities and character of the future lawn. The selection of grass mixtures should therefore never be underestimated.

Sowing can be done from spring up to the end of autumn with consideration of soil and climate conditions. Sow the seeds with a sowing machine or – broadly– by hand. Before sowing, it is a good idea to mix the grass mixture seeds and divide them into two equal portions. The first portion of seeds should be sown lengthwise, and the second perpendicularly to the first. That way, a uniform sowing pattern is achieved.

After sowing the seeds, lightly rake to a depth of 2–3 mm. Pack down the surface with a garden roller, for instance. Water moderately until the grass emerges.

Depending on the grass mixture selected, the seeds should germinate in 20–35 days. The sowing rate of the grass mixture should be within a range of 10–30g per m² depending on the quality of soil preparation, type of grass mixture, and sowing technique.

Principles of grass seed dosage while sowing:

Grass seed weight	For an approx. area of
0.5 kg	20 m2
1 kg	40 m2
2 kg	80 m2
10 kg	400 m2
25 kg	1 000 m2

Watering an established lawn

During germination of a newly established grass area, it is necessary to keep the topsoil layer constantly moist until the grass emerges. If the soil starts to form a crust during the germination period, it is essential to break it up carefully using a rake or fluted roller.

While watering, take heed that sown seeds do not start floating in the stream of water. For that reason, use a garden sprinkler with a fine spray. It is best to water intensively in the morning or evening hours.

Mowing the grass

A newly established lawn should be mowed at a height of approx. 80–100 mm and, as a rule, with a sharp instrument (scythe, sickle, or reaping knife). The height can maximally be lowered by one third of the total grass height. In the first cutting, liquidate at least 90% of the individual weeds, which emerge at the same time as the grass seeds (weeds from the soil supply). After the third cutting of a newly established lawn, one may start mowing at the height desired. Repeat further mowing according to grass type and increase in grass mass at an average of 1 or 2 times per week.

Recommended lawn height

Grass type	Recommended lawn height
Newly established lawn	60-70 mm (for the first three mows only)
Park grass	40-60 mm
Playfield grass	25-35 mm
Technical grass	50-70 mm
Profession grass fields
Football field	25-35 mm
American football	25-35 mm
Rugby	25-35 mm
Golf fields
Tee	10-15 mm
Fairway	25-30 mm
Fore green	10-15 mm
Green	5-8 mm
Rough	30-70 mm

3. Agro-technical principles and measures

Generally, agro-technical measures are applied primarily in the spring and autumn.

Nutrition and fertilizer

The foundation of a perfect lawn is sufficient and balanced nutrition, which influences the quality of grass growth and its resistance to stress, diseases, and being walked on.

Frequently mown park, golf, and high-wear lawns are very demanding when it comes to nutrition. The amount of nutrients needed is best determined by analysing the soil and visually appraising the grass growth and recommended doses of fertilizer.

Nutrients should be supplied by using organic fertilizer, or industrial fertilizer in granulate or liquid form. Organic fertilizer improves the physical qualities of the soil, increases nutrient fixation in the soil, and increases the effect of the soil’s micro-flora and water absorption.

Try the new AROS POWER^® grass fertilizer.

Basic nutrition elements:

• Nitrogen (N) - promotes grass growth and rootstock intensity
• Phosphorous (P) - influences rootstock setting and root structure growth
• Potassium (K) - increases the grass’s resistance to diseases, damage from winter frosts, and lack of water

Supplementary elements:

• Calcium (Ca) - a building block for plant cells
• Magnesium (Mg) and Iron (Fe) - important green leaves and the formation of organic mass

Dosage of pure nutrients (Nitrogen, Phosphorous, Potassium, Magnesium) in kg/100m²/year

Grass type	Nitrogen	Phosphorous	Potassium	Magnesium
Park grass	0.55-0.75	0.25-0.45	0.8-1.2	0.1-0.2
Playfield grass	0.75-1.6	0.25-0.45	0.8-1.2	0.1-0.2
Technical grass	0.30-0.75	0.25-0.45	0.8-1.2	0.1-0.2

For professionally-maintained lawns (especially golf courses and football fields), increase nutrient dosages shown on the table by 10–15% as needed.

Scarification

Scarification is the vertical cutting of lawn sod. It is accomplished using a special scarifying rake, or a motorized scarifying on larger surfaces. The blades dig to a depth of 3–5 mm into the root zone, cleaning the grass sod of dead grass and enabling the access of water, nutrients, and light to the grass. Raked-up remains can be used as compost. After taking this step, it is important to fertilize the lawn, best with a fully-combined fertilizer if the lawn is in good condition, or, for a damaged lawn, a quick-dissolving nitrogen fertilizer for timely regeneration.

Aerification

Aerification means the airing-out of the soil with an aerification fork or aerification roller. The hollow tips of this tool penetrate to a depth of 100-120mm, from which they bring brome soil up to the surface. The apertures that appear are filled in with high silicate sand, which helps improve the air and water proportions in the soil. Apply it in instances where the grass sod and soil gets packed down hard or if the surface gets over-watered.

4. The AROS range of grass mixtures

As one of the prominent Czech grass mixture manufacturers, AROS-osiva ltd. markets a wide offering of mixtures and packaging on the market in individual product lines.

Grass mixtures

5. Most widespread lawn diseases and measures to limit them

Snow mold (Fusarium nivale)

Grass begins dying in a round, elliptical, or irregularly shaped area. Grass blades are covered with a mycelium fungus off-white or pinkish in colour. The disease mainly manifests itself after the fall of snow. It is primarily caused by the failure to clean up and remove organic matter, snow on unfrozen ground, solidified surface soil, and an overabundance of nitrogen in the autumn. The affliction is stronger in shady places. The lawn takes on a brownish to brown colour and regenerates very slowly.

Countermeasures: Thoroughly rake up dead matter and fertilize with calcium nitrate or ammonium nitrate with lime. In the event of a serious attack, apply fungicidal treatment.

Typhula blight / Grey snow mold (Typhula incarnata)

Brownish spots of various sizes that appear after snowfall, the colour of which turns grey to white. The development of this disease is caused by long-term laying snow, temperatures between 0–10 degrees Celsius, and high air moisture. An abundance of waste likewise forms a microclimate, which causes the disease to thrive.

Countermeasures: Thoroughly rake up dead matter and fertilize with calcium nitrate or ammonium nitrate with lime. In the event of a serious attack, apply fungicidal treatment.

Powdery milder (Blumeria graminis)

An off-white coating that forms on blades of grass and turns into more extensive brownish spots. The grass blades gradually die. Caused by over-dense grass growth and trimmings, high air humidity, and shady areas.

Countermeasures: Growing resistance species, balanced nourishment, and frequent mowing limit the spread of the disease. In the event of a heavy outbreak, apply fungicidal treatment.

Crown rust (Puccinia coronata Corda)

Fuzzy yellow and orange bumps appear on the grass blades accompanied by chlorosis and necrosis, which turn into shiny black spots. Gradually leads to the destruction of leaf tissue. Caused by extensive piling up of chopped grass, inadequate nourishment, high temperature and air humidity.

Countermeasures: Balanced nourishment and more frequent mowing are effective in inhibiting this disease.

Black stem rust (Puccinia graminis)

Dark, rusty, fuzzy summer spore sacs appear around the joint and on the lower portion of the stalk. Later, winter spores appear dark black and bulging. This gradually leads to tissue destruction, and to the grass blades twisting up and drying out. Caused by excessive watering, frequent dew and heavy rain showers during higher temperatures.

Countermeasures: The disease can be limited by watering only during the evening hours.

Red thread (Laetisaria fuciformis)

Irregular spots appear in grassy areas, which later turn yellow and take on a rice straw colour. Pink coloured air mycelia fuzz appears during high humidity. The disease mainly strikes in autumn. Caused by insufficient nitrogen nutrients, long-term wetness, and frequent mist or fog.

Countermeasures: Effective methods of limiting this disease include regular and balanced nourishment, cutting the lawn back, and, if need be, fungicide treatment.

Fairy ring toadstool (Marasmius oreades)

Mushrooms of the Basidiomycetes order, which primarily emerge in older lawns, poor and sandy soil, densely packed soil, and former forest soil. It emerges looking like a dark green circle with an abundance of nitrogen from the decomposition of wood, or in the form of zones of dead grass with whitish mycelium fungus or circles of sporophores.

Countermeasures: The disease can be eliminated by replacing the topsoil layer to a sufficient depth and sowing grass mixture over the new topsoil.