Dye plants
We grow an ever changing list of plants for vegetable dying.  This is a short summary of the most useful and interesting varieties.  I'm not attempting to write an encyclopedia, it's just my personal take on the growing experience.

Coreopsis (coreopsis tinctoria)

Orangey yellows are produced from the Coreopsis flower heads which can be used fresh or dried.  This annual plant generously produces very pretty and fragrant flowers from June/July right through to the end of summer.  It appears to be very tasty to bees, butterflies, and unfortunately rabbits, so you may need to protect yours from unwanted invaders.  If allowed to it will self seed, you can also collect seeds to sow the following spring.    

Dyers Chamomile (anthemis tinctoria)

The flower heads used fresh or dried will produces soft yellows.  This perennial plant produces an abundance of flowers all the way through summer.  It is easy to grow and has survived the rabbits.  The bees and butterflies love it too.  The seeds can be collected and sown in the spring.

Indigo (indigofera tinctoria)

This perennial plant requires constant heat, humidity, and feeding. You need to treat it like a family member, so it is not for reluctant gardeners.  In Scotland it is only suitable as a pot plant indoors or in a heated greenhouse.  The seeds are also fairly tricky to germinate firstly requiring soaking before they are planted, and then to be kept in a heated propagator.  If you manage to keep your plants alive for a year or two you may be able to collect enough fresh leaves to produce the famous beautiful intense blues.  

Japanese Indigo (persicaria tinctoria)

Japanese Indigo is a perennial plant, it is tender to frost and is also best grown in a pot indoors in Scotland.  It is  very vigorous, and easy to germinate and propagate.   
The fresh leaves of Japanese Indigo will produce an array of blues.

Madder (Rubia tinctoria)

Madder roots produce stunning orangey reds and pinks.
   It is a perennial and is easy to grow.  Young plants need to be protected from slugs and snails.  It is not pretty on the surface, being related to bedstraw or if you are in Scotland "sticky willy".  The leaves and stems are covered in prickles and it can cause a rash 

Rhubarb (Rheum rhabarbarum)

Rhubarb is an easily grown perennial, familiar to most people in the UK because of its use in puddings such as Rhubarb Crumble, or Rhubarb and Custard.
 The leaves can be used to create a mordant, and the roots can produce pinks and browns.  To create a mordant the leaves are boiled down for an hour and strained.  The leaves contain oxalic acid so the leaves and the resultant mordant is toxic and all the usual precautions should be taken when handling toxic substances. 

Weld (Reseda luteola)

Weld produces an intense limey yellow from the flower spikes, and can be used fresh or dried.  Weld is a biennial and is quite easy to grow from seeds which can be collected and sown in the spring, it will also self seed if allowed.  This year my young plants have been attacked by the dreaded rabbits who don't eat it they just seem to enjoy digging it up and leaving it.  Protect them if you live rurally.  

Woad (Isatis Tinctoria)
Woad is a brassica that likes a limey soil and plenty of nitrogen.  It is easy to grow but is susceptible to the same issues as other brassicas such as club root, caterpillars, slugs and snails.  It is not a particularly attractive plant but  it does produce beautiful bright blues.