Complex sentence: The ground under the house has been compacted and made a bit higher than the area around the house, the soil is prevented from seeping away by edgings which in colonial times were made of bottles planted into the ground bottom-up.
Split into simpler sentences: The ground under the house has been compacted and made a bit higher than the area around the house, the soil is prevented from seeping away by edgings around this compacted soil. In the colonial era, the edgings were made of bottles planted into the ground bottom-up.