The area that it has decided to grow in is really quite rough - the black bag contains sawdust and scraps of wood from John's workshop (we use them to soak up the mud that we get when it rains here, it can get like a swimming pool in our back yard!)
This is of course the preferred environment for the Weld plant, the scrubbier the better almost, we used to go to Tesco to collect it - there was a new car park and the ground was turned over and left - it was a fabulous crop for a couple of years - but sadly it's been cultivated now!
It now appears that I have a Weld tree! It is in flower and looking magnificent, it reminds me of a Christmas tree with candles attached to the ends of the branches all lit up! it is higher than the doorway into John's workshop and takes up so much space that you can barely get past it! I am not going to cut it down yet - it's not quite ready, but it shouldn't be long! Actually I feel quite guilty about cutting such a fantastic plant down I wish they went on and on!
There has been lots of debate about when the best time for cutting is, I am no expert and seem to have cut weld at all stages of flowering and even almost dead over the years, and had colour from all of them, hard to actually say which I found the best. Sadly I have been very remiss about keeping records of cropping times. One day I would like to have enough weld growing to do an experiment and start cropping from when first in flower right through to when almost dying off. What I can say is that the Weld I have collected from the East of the country (York area and Norfolk/Suffolk) has yielded a much better colour than that grown here in the West (Oswestry, Mold, Whitchurch).
There has been a project in Italy looking at yields from various varieties of weld with a view to turning it into an agricultural crop. Its title is Agronomic potential of Reseda luteola L. as new crop for natural dyes in textile production by Luciana Angelini, Alessandra Bertoli, Sabina Rolandelli and Luisa Pistelli. from the abstract:
Six weld genotypes were evaluated for their agronomic characteristics in a 4 year field study carried out under rainfed conditions in Central Italy in order to point out productive potential and the best harvest time to maximise yield of dye.......the harvest of plants during flowering or during beginning of fruit ripening did not affect overall dry yield. The luteolin amount was affected by climatic conditions as experienced in two different growing seasons and by the plant phenological stages at harvest being luteolin most abundant in the driest year and in plants harvested during flowering. Genetic variablility existed for the luteolin content in leaves plus reproductive structures (inflorescences and fruits) that varied from 13.6 to 28.7 mg g-1 dry weight in the six accessions tested. Separated weld organs showed different dyeing capacities being the leaves, inflorescences and fruits the most effective ones..............
Their results seem inconclusive due to the effects of rainfall but they consider the best time for harvesting is when flowering as that is the highest luteolin content. They don't use the stems of the plants - they consider there is no colouring matter there.
There is so much to learn..........!