Vikrom Suebsaeng's one-storey house in Muang Ake was submerged in 2.30m of stagnant water for more than six weeks. The flood took almost everything away and repairs have been estimated at about one million baht. About 70% of the trees and plants on his 325 wah (1,300 square metres) of land have died, the soil has hardened and the grass is gone. ''My worry is not with the trees or plants which can be bought and grown again,'' he wrote. ''I want to have my grass back and would like to have your advice on the most economical way of reviving the soil so that I can have beautiful green grass again.''
last year’s floods caused untold damage to homes and property, and wiped out lawns as well as prized plants.
Immediately after last year's deluge, sod was in short supply as growers were also affected by the floods. However, during a visit to Nakhon Nayok a few months ago, I saw that nurseries along Khlong Rangsit in Ongkharak had begun to revive their stocks of plants, and suppliers were beginning to sell sod again. There are plant stalls near Muang Ake so Mr Vikrom may be able to find sod for sale near his place. These squares of pre-grown grass can be easily laid down to convert bare ground into lush lawn in no time.
The rainy season is an excellent time for laying sod, but with some provinces along the Chao Phraya now under water, Bangkok is in danger of being flooded again this year. Therefore, I suggest that Mr Vikrom wait until he is sure there won't be a repeat of last year's floods before he revive his lawn.
When I was in grade school, one of our extra-curricular activities was planting the playground with turfgrass. Pieces of bermuda grass were planted 10cm to 15cm apart and watered regularly. After about two months, the grass formed a carpet that covered the playground. To economise, I used the same method in establishing a lawn in our country home.
Apart from fertilising and proper watering, mowing is a critical part of turf management .
Sodding is an expensive way of establishing a lawn, but it is the least problematic and you get instant ground cover. Before you can lay down the sod, however, you have to prepare the ground first. The soil on Mr Vikrom's lawn has hardened but if there are weeds growing on the site, strip them off with either a shovel or a hoe, then rake or sweep them away so they don't grow again.
The stagnant water must have made the soil acidic, so scatter lime to improve the soil pH, and compost or humus to make it porous. With a hoe, till the ground to loosen the soil, and to blend it with the lime and compost, until it is broken into pea-size granules to a depth of about 15cm. Next, spread a high-phosphorus fertiliser such as NPK 10-20-20 or NPK 5-15-15 (or their equivalent) to improve root growth, and hoe the ground once again to incorporate the fertiliser into the top 7cm of soil. To prevent puddling during watering, make sure that the ground is a bit higher in the centre than on the edges. Finally, rake the surface smooth, discarding rocks and pebbles, weed roots and other debris as you go along, then stomp on the soil to firm it.
Choose sod carefully to ensure it is not infested later with weeds. To provide moisture, the plot must be irrigated several days before the planting date, and the soil must be moistened before the sod is laid. To place the first row of sod along a straight line, use a string pulled taut between two stakes as your guide. Taking care to avoid tearing the sod, press it firmly into position. Lay the pieces tightly edge to edge, so that there are no gaps between the squares for weeds to grow through, until you have covered the whole area.
If you are working on a sunny day, sprinkle each strip with a hose as it is laid to keep it from drying out. Newly laid sod should be rolled over with a partially weighted roller or stepped on to ensure good contact between roots and soil. Use a bamboo rake to fluff up the grass blades lightly and to remove any soil or pieces of sod that may have fallen on the grass as you worked, but afterwards keep off the lawn until the grass is fully established. If it does not rain, the lawn should be watered regularly during the first several weeks to ensure proper establishment of roots in the topsoil.
To maintain a dense turf, apply a slow-release, high-nitrogen fertiliser every three months. When watering, make sure that the soil is thoroughly soaked to encourage the growth of deeper roots. Watering less frequently but thoroughly is better than wetting just the surface every day. Light watering encourages the roots to grow up the soil in search of water, thereby making the grass more susceptible to drought. The best time to water is early in the morning or late in the afternoon to minimise water loss from evaporation.
Healthy grass growth chokes out weeds in the lawn and impedes their growth. Apart from fertilising and proper watering, another primary practice critical in turf management is mowing. Depending on the grass variety, a height must be established and a mowing schedule adopted to maintain it. In this way, the grass is able to adapt to the routine and not experience shock. The rule of thumb is that, at any mowing time, no more than one-third of the leaf should be removed. If the grass is left to grow too tall, it will be necessary to cut more than half of the leaf, thus limiting the translocation of food to the roots for proper growth. What's more, an overgrown lawn encourages the growth of tall weeds.
before establishing a lawn, rocks and pebbles must be removed and the soil made porous with compost.
About the author
- Writer: Normita Thongtham