Reel and Lines or Garden Lines started to become useful in the C18th.
As much to do with the allotment as the garden, they allow gardeners to sow seed in straight lines; many plant seeds look familiar when they first shoot above the soil. As plants grow; when sown in a straight line, bearing the name of the plant at the front of each section, hoeing the small weeds away is easier.
It also means that the correct spacing for each plant can be pre measured, ie carrots do not need as much space as savoy cabbages for example.
Nige has, as ever taken the example of an C18th line, and forged some lines with a few improvements. Instead of using jute of a brown hue which may get lost in use, we are using colours such as red and turquoise that are easier to see in the soil and amongst plants.
Once the desired length has been reached it can be tightened enough to hold the shape and then pushed down firmly in order to secure it.
Lots of other elements in the garden can make use this device, ponds, seating areas, grass, naturalised bulbs or wild flower areas (which only need mowing a couple of times a season); round beds for underplaning large shrubs and trees and hedges which need lots of plants set alternately to produce a full, lush look. They just can’t be trusted to grow neat and straight!