I think those must have been the Edgbaston Guinea Gardens, Pedro. Basically, allotments would be their later equivalents. Found this description of the early guinea gardens:
The rent of 1 guinea meant they came to be called ‘Guinea Gardens.’ A guinea represented at the time a considerable proportion of a man’s wages.
James Drake writing in 1825 claimed these small gardens promoted ‘healthful exercise and rational enjoyment among families of the artisans; and, with good management, produce an ample supply of those wholesome vegetables stores, which are comparatively seldom tasted by the middling classes when they have to be purchased.’
J.A. Langford writing of the period 1810-1820 said that‘the Guinea Gardens were in very large numbers'. It was a ‘hobby’ with the Birmingham working man and the cultivation of flowers was carried to ‘great perfection by him.’ These gardens then flourished, were enjoyed by middle-class families and were regarded generally as highly desirable. The peak of this provision was between 1820 and 1830 after which the sale of much private land for industrial, residential, road or railway projects associated with the now accelerating urban expansion caused the decline of the system. By 1886 only 3 such sites remained and only one continues as allotments today
From what I can make out from adverts in the late 1700s into the early 1800s, the Nova Scotia Gardens were divided into single plots separated by "walks" and being used to grow a range of fruit, vegetables and flowers. Occasionally, there is a double plot for sale.
I can't say for certain, Pen, but it looks like NS Gardens most probably were originally 'guinea plots' or organised on a similar arrangement, and only available to those who could afford them.