The suburbs are expanding, with new properties mushrooming all over the place. After construction work has been finished, the builders will only clear up the site and level off the ground, at most. So it is down to the new owners to face the challenge of tidying up and planting the plot.
Some new home owners are lucky enough to buy a new property with lawn and several trees installed; however, their joy is often short-lived. During construction of the house, the builders hardly ever take care to preserve the soil intact – the soil layers get mixed up, new holes are excavated and later backfilled, and then dug out once again. The builders use these cavities to bury all sorts of building rubble, filling them with the soil later, which has been previously removed from the construction site. Sometimes they go to the trouble of spreading a thin layer of peat on the surface and planting several young trees. And so it is the new owners, who uproot the dead trees, haul in truckloads of compost, and plant anew.
Shallowly buried building rubble can be a major obstacle for a new garden. Thick layer of broken bricks, concrete and other rubbish makes an impenetrable barrier for the plant roots. Shallow-rooted plants, such as most fruit and ornamental trees, will hardy grow on the site, where building rubble was buried shallowly. Sometimes it happens that only a very thin layer of soil covers the buried rubble, which is too thin to support even a lawn. If the building rubble has been buried only in a few patches rather than being deposited all over the place, these problem spots can be used to make alpine or raised beds.
Sometimes a part of lawn can collapse into a hollow or even a major cavity, following winter or a heavy rain. This usually happens when building waste is deposited at varying depths or when some of the rubbish is hollow, which allows water to carve into it and causes the cave-in. The cavity should be filled with compost and sown with lawn seed, or alternatively, you could remove the turf, backfill the hole with the soil, water a few times to compact well, and replace the turf. It is generally suggested to refrain from planting right after the building is over. A waiting period of a year is sufficient to discover all the faults of the plot, if there are any.
On clay soil, the heavy building machinery can compact it to a thick and impermeable hard layer, which prevents water from draining freely. On such a site, surrounded by a fence, and crisscrossed by several garden paths built on concrete base, you will end up with a number of large soil “pots” without any drainage holes. Even with the thick layer of compost some plants will refuse to grow due to waterlogging. In such case, consider installing some drainage system under the paths or concrete foundations. And if you intend to plant any fruit trees, remove the solid layer altogether, when digging the planting holes.
Sometimes builders use sand to level off the ground, with a thin layer of compost spread on top to sow the lawn. Such a lawn will require frequent and abundant watering, and will dry out fast during droughts, sand being very free-draining. Planting holes for trees and shrubs should be filled with soil, amended with peat, clay and well-rotted manure.
Mature trees are usually preserved when constructing houses. The ground is leveled off around them, with plenty of brought-in compost. And sometimes mature trees, which have been growing successfully on the site for 20 year, start going into decline for no obvious reason. The most common cause is that the majority of trees dislike their trunks being buried deeper than they have been growing before. Spruces and pines die back when their trunks are covered with another 15 to 20 cm of soil; birches, oaks and limes survive, but their tops start turning brown. Since conifers are slow to die, spruces and pines retain their green needles for another couple of years, but deciduous trees drop their leaves during the same summer. Bird cherries, poplars and most shrubs survive such treatment, since they break new roots from the stems, when these are buried under a thick layer of soil.
© Giedra Bartas, 2010