From John Smith:
In her 1968 report on Devon dialect [1] Gillian Moore recorded the following advice for ridding ground of thistles [Cirsium spp.]:
Speed them in May
They are up the next day.
Speed them in June
They will come again soon.
Speed them in July
They soon will die.
She suggests that ‘speed’ stands for ‘spade’ = a Devon word for a breast plough. My view is that speed = spit, in other words, use a thistle spitter to grub them out. Apart from anything else, I feel that no one would have used a breast plough to get rid of thistles. Has anyone any comments?

[1] G.F. Moore, 71st report on dialect, Report and Transactions of the Devonshire Association for the Advancement of Science 100: 367-71, 1968.

Comments:

1. Unfortunately we don’t know the species of thistle to which the rhyme refers. Of the thistles (Carduus and Cirsium spp.) which are considered to be weeds most are biennial and grow as isolated plants, but one species, creeping thistle (Cirsium arvense), is perennial and can form large dense colonies. The biennial species are best removed by digging them up one by one. Creeping thistle requires different treatment, clearing the whole area in which the colony grows, and possibly a breast plough would be an efficient implement to use for this [RV, 10 February 2011].

2. I questioned my father about this. He has spent all of his life farming on the Devon/Dorset/Somerset borders, and is now aged 89. He had no idea what ‘speed’ means, but had some information about controlling thistles. According to him there are two types of thistle: bull thistles [marsh thistle, Cirsium palustre], and sheep thistles, which seem to be the perennial creeping thistle. Bull thistles are removed one at a time; ‘you don’t need to dig up the whole root, just cut it off just below the ground, but make sure you get every leaf [out]’ and they will die. Sheep thistles, which spread by spills* – white roots or runners below the soil – were cut with a hook, once or sometimes twice a year. This didn’t kill them, but prevented them from seeding. ‘That was before they had sprays to kill them, you don’t see so many today’.
* I can’t recall having heard him use the word ‘spill’ in this context before. If I heard him correctly, he also mentioned the spills of bull thistles, meaning stems [RV, 22 February 2011].

3. Spill = the stem of a plant, especially one that is long and straight. A spill-more is a tap-root and to run to spill is to run to seed [John Smith, Dialect Recorder, Devonshire Association, 23 February 2011].

4. Run to spill – a biennial plant, such as some of the thistles we’re discussing, produces a basal rosette of leaves during its first year, and then produces a stalk (spill) which produces flowers, and eventually seeds, during its second year [RV, 24 February 2011].

Images:  upper, creeping thistle, Stonegate, East Sussex, July 2015; lower, basal rosette of marsh thistle, South West Coast Path between Clovelly and Hartland Quay, north Devon, March 2014.

Updated 7 July 2015.