Category Archives: Self-seeding

Yellow pea like flowers of Genista blossom

Growing Dyers Greenweed (Genista tinctoria)

By Ashley Walker
Copyright 17th February 2020

Dyers broom, Dyer’s whin and Woadwaxen

Dyers Greenweed is a member of the Fabaceae or legume family. It is a typical shrubby broom native to the UK, growing in open pasture and heathland. It is a source of an excellent light fast lemon yellow dye similar to Weld. As its name suggests it was used with indigo (from Woad) to dye textiles various shades of green.

Horticulture

Like some other native dye plants, Greenweed has declined with the rise of modern agriculture so you are less likely to be able to forage for it. It mostly grows in the West and South of England and appears to prefer slightly acidic loamy clay soils though it will grow in alkaline soils if treated well. It can grow to a height of 1 to 2m and forms a bush, usually growing from a single base stem. There are dwarf varieties and a dwarf subspecies Genista littoralis. It is extremely hardy (surviving temperatures as low as -35ºC) so it should be possible to grow it in the far North. It loses its leaves in the winter and this maybe the reason it’s able to stand the sub-zero temperatures. It does not like being waterlogged but struggles in dry soils too when it needs to be watered occasionally during hot summers.

Dyers Greenweed bush growing in the author’s back garden.

Propagation

The seedpods of Greenweed turn black in late summer and on hot days burst apart scattering the  small pea shaped brown seed.

to show the seeds and seed pods of the plant

Seeds and pods of Dyers Greenweed

These may germinate in the Autumn or stay in the soil and germinate in the following spring. When I first tried to grow the plant from seed I followed the instructions to plant in the Autumn. Although some of the seeds germinated I found that the seedlings died during the winter. so I changed my strategy to planting in Spring which works very well and allows the seedlings to grow large enough during the first year to get through winter without problem.

Start seeds off indoors in modules or seed trays from March to April and plant out in June in a sunny position.

to show what a young seedling looks like

This very young Dyers Greenweed has self seeded but is in danger of being eaten by slugs.

The plants will grow large, so give them plenty of space and plant about a metre apart. They can be grown as a hedge in which case plant closer (say 20 to 25cm). The seedlings are very prone to slug and snail attack, so sowing the seed outdoors is very risky without protection. Cuttings can also be taken. Cut the woody 1 to 2 year old stems in Spring or Summer and just stick them into the soil. Only about 10 to 50% will take so plant more than you need. They will need watering regularly during the summer as they take a month or two to root.

Pests and diseases

shows red ladybird eating aphid pests

Ladybird to the rescue

Aphid on young shoot of Dyers Greenweed

Apart from slug and snail attack when young, the next big problem is aphids, which attack the young shoots in early Summer just when you want to be picking them for dye. The damage can be extensive and I sometimes have to resort to spraying them off with a jet of water from the hosepipe. Ladybird and hoverfly larvae usually get the aphid under control by mid to late Summer and the plants will recover enough to flower. There appears to be quite a bit of natural variation amongst plants with some consistently being attacked and others being generally free of the bugs. So if you find you have a resistant plant don’t hesitate to take cuttings from it.

Deer and other large herbivores also like to eat Greenweed.

Maintenance

The young shoots are best for dyeing. As the plant gets older it produces fewer shoots so the bush needs to be pruned or cut back at least once a year to encourage this new growth. In earlier times when the plant was grown as a source of dye it was typically harvested in the second year when the whole plant was cut down. During the early Spring/Summer take the first harvest of young shoots then cut back in August to get a second growth and harvest. Growing this plant as a low hedge is ideal.

Dyers Greenweed will regrow quickley after being cut back and produce lots of new shoots.

As a member of the legume family, Greenweed is capable of fixing nitrogen in its root nodules. As a result the plant does not need much, if any fertilizer and can grow on quite poor soils. Don’t plant Greenweed in your most fertile bed, so choose instead any bit of scrappy ground that gets full sun. Greenweed will not grow in heavy shade. Against a South facing wall or fence would be ideal. To help keep weeds down after planting you can add some thick mulch around the stems. Water if the soil becomes very dry.

Cultivars

Greenweed is grown as a decorative garden plant for its bright display of yellow blossom in mid to late Summer. If you grow several plants from seed they will probably have slightly different flowering times but if you buy a commercial cultivar each plant will flower at the same time. Commercial cultivars may also be less able to cope with strong pruning and are usually a lot smaller than the wild plant. Three cultivars of note are:

  • Royal Gold – 0.5 to 1m
  • Humifusa – dwarf variety
  • Flore Pleno – dwarf variety

Dyeing

The leaves and young shoots are treated much like Weld except if the stems are woody strip the leaves first. Boiling water is poured on the cut shoots and left for an hour or so to extract the dye. Fermenting the young shoots can also have excellent results. A small amount of alkali (lime water or a drop of ammonia) will bring out the yellow. Dye your textiles in the resulting extract at around 70ºC. This dye is excellent for silk. If dyeing green with indigo a slightly better result will be obtained if you dye indigo first and then over-dye with  Greenweed. The young shoots can be dried for storage and later use.

Silk and Cotton dyed with Dyers Greenweed

Field Madder plant showing tiny pink four petaled flowers

Natures Rainbow Garden Update – Spring 2019

By Ashley Walker
Copyright 8th May 2019

The weather here has followed the pattern of recent springs by being dry, sunny and warm with cold intervals and frosty nights. Planting out of the Japanese indigo will have to wait for a week or two yet but most plants are thriving. Time to look at last year’s plantings and make an assessment of what has worked and what has not. Last year we embarked on growing a number of new plants, many of which are relatives of Common Madder. Of course many folks have said “What on earth are you doing that for? There is no better plant than Common Madder!” That of course is true but in the past many of these madder relatives were used as dye plants and prized for their colours so we thought we’d try and find out for ourselves how easy they are to grow and eventually what colours their roots will yield.

Wild Madder Rubia peregrina

We first started with Wild Madder (Rubia peregrina) three years ago now. Spring frosts have been particularly hard on the plants as their evergreen upper leaves are not particularly frost hardy.

Browned and crisped frost damaged evergreen leaves of Wild madder, Rubia peregrina.

Frost damaged evergreen leaves of Wild Madder.

Their native UK homelands are the southern coastline of Devon, Cornwall and Wales where they get warm sea breezes that usually prevent frosts, so here in Hertfordshire they are a bit out of their depth. However the roots are protected and soon shoot back once the warm weather returns. Getting a good harvest from the plant is going to take time, even without frosts it’s very slow growing so we’re not planning to dig any up until Autumn this year.

Shoot of Common Madder (Rubia tinctorum) showing browned shoot as a result of frost damage.

For the first time in many years our Common Madder shoots were badly frosted. Not a problem as the plants quickly produce new shoots

Even our Common Madder beds were badly affected by the frosts with many of the new shoots being crisped.

Field Madder Sherardia arvensis & Hedge Bedstraw Galium mollugo

Field Madder Sherardia arvensis A cushion of Field Madder growing under a Weld plant with Sawort to the left. This plant self seeded last year and has come through the winter without any frost or snow damage.

A cushion of Field Madder growing under a Weld plant with Sawort to the left. This plant self seeded last year and has come through the winter without any frost or snow damage.

Generally described as an annual weed, we discovered that given plenty of attention this plant is perfectly capable of going through the winter and withstanding any frosts. Does this make it a short lived perennial? Many hardy annuals can do this and provided they are watered and fed can keep on growing. As this plant has very thin roots, getting a harvest is obviously going to be a bit of a test so we’ve decided to do a little experiment by growing Field Madder and another similar relative Hedge Bedstraw Galium mollugo in large pots in a compost mix that should be easy to wash away from the roots at the end of the year.

Large plant pot containing seedlings of Field Madder Sherardia arvensis

Large pot with seedlings of Field Madder.

Hedge Bedstraw Galium mollugo

Large pot of Hedge Bedstraw seedlings.

Dyer’s Woodruff Asperula tinctoria

Over the winter I managed to get hold of some seeds from Rühlemann’s in Germany but unfortunately none of these have thus far germinated. As a native of the northern steppe lands of Europe and Asia this may mean they need vernalization. Some of the plants we obtained from Scottish plant nursery (Poyntzfield Herb Nursery)  died towards the end of last year. Plants placed in an ericaceous compost in tubs seemed to do better than those planted in the chalky soil of our Nature’s Rainbow dye garden. This goes against the generally accepted advice that the plant likes alkaline soils. However, It may be other factors were involved. All of our plants died back really quite early in the year and we were afraid they might die out altogether, but back they have come this Spring and they look quite healthy. They have reappeared at the edge of the planters, showing that last year they tried to expand by producing underground stems much like Common Madder. I guess that this means they are capable of also being quite invasive!

Feathery Green shoots of Dyers Woodruff Asperula tinctoria

New shoots of Dyer’s Woodruff in the alkaline soil of our dye garden.

Ladies Bedstraw Galium verum

This plant has done really well in a whole variety of settings and soil types. It’s also very well behaved with minimal spread. It looks good throughout the year, with pretty clumps of feathery foliage followed by a spray of small yellow flowers in the summer. With its historic interest as a bedding straw, its use in dyeing  and its versatility as an ornamental garden plant, I feel that this plant is a must for any dye garden.

Feathery green clumps of Ladies Bedstraw Galium verum growing next to the greenhouse.

Clumps of feathery green Ladies Bedstraw growing by the greenhouse.

Alder Buckthorn Rhamnus frangula & Purging Buckthorn Rhamnus cathartica

Alder Buckthorn Rhamnus frangula. New shoot showing "alder " shaped leaves and blossom buds.

New growth of Alder Buckthorn.

New growth of Purging Buckthorn Rhamnus cathartica

New growth of Purging Buckthorn.

We tried planting Alder Buckthorn, an acid soil loving shrub, in a variety of conditions. Those planted in ericaceous beds or tubs have done well but those planted out in a wild setting in the chalk soil here have suffered greatly, though it has to be said, the most damage was done by muntjac deer who clearly have a liking for it.
The Purging Buckthorn did less well, to my surprise. It’s not supposed to be fussy about soil type. No casualties, but the plants have not grown very much in the last year. Although it could be that this plant simply takes longer to get established. The new growth this year looks a lot better.

As yet the plants are too small to risk any harvesting but I suspect it is the Alder Buckthorn that will give the better dye.

Tibetan Madder Rubia Cordifolia (Indian Madder or Munjeet)

We are now the proud owners of one of these plants. Obtained from the German Herb nursery Rühlemann’s, this plant spent four and a half days in a box being transported across Europe, the English Channel and finally to our door and arrived in perfect condition! Many thanks to Rühlemann’s  for doing such a professional job of packaging it up, we have great admiration! The growing tips had faded a little during transit but greened up rapidly on exposure to light.
According to the literature these rather elegant looking plants should just be able to survive outside in the UK, though I’m not taking any chances until I’ve had a chance to propagate some cuttings.  At first sight it looks quite different to Common Madder but it has the same leaf whorls (but only 4 leaves to a whorl as opposed to Common Madder’s 4 to 6) and has hooks on the square and weak stems just like madder and cleavers. It obviously has the same growing strategy i.e. it clambers over other plants, holding on with its small hooks.

Tibetan Madder Rubia Cordifolia (Indian Madder or Munjeet)

The Munjeet plant about a week after arriving. Repotted to a larger pot and already starting to grow and looking very healthy indeed

Rubia Cordifolia plant just after delivery and repotting

Rubia Cordifolia plant just after delivery and repotting

We are ridiculously excited by this latest acquisition and look forward to see how it grows and what sort of dye giving roots it has. According to Cardon* its chief dye substance is munjistin which gives a very bright orange. Like common madder it also contains many other dye stuffs, including a very large range of yellow to red anthraquinones. Alizarin is present but only in small amounts so the overall light fastness is probably not as good. Cardon mentions that there are different varieties of cordifolia as well as a very closely related species (Rubia akane) that grows in Japan. Our plant is advertised as being from Tibet, so hopefully it will be able to cope with frost during the winter.

Self-seeding

Bed of hundreds of tiny self seeded Weld seedlings

A mass of tiny self-seeded Weld seedlings in the dye garden

Cota tinctoria

Self-seeded Dyers Chamomile seedlings

 

Madder Seedlings Rubia tinctorum

This year we have had a number of self-seeded Common Madder seedlings in planters positioned near the house. They have produced seedlings in the garden during the Autumn before now, but these usually die during the winter. I think the weather has been just right this year to encourage spring germination and the temperatures near the house have prevented any frost damage.

 

 

 

 

 

Finally a little note on self-seeding of dye plants. We have always tried to encourage plants to self-seed in our garden, with some success. We have been growing the plants for a long period now and the soil is loaded with seed. Weed plants have been under control for several years, so there should be nothing to stop those plants which can self-seed from doing so. So here’s a check list of what you need to do to follow suit:

  1. Allow your plants to flower and drop their seeds. This can produce, in some people’s eyes, an untidy garden but there are so many advantages including encouraging wildlife and saving your time growing the plants from seed and planting out every year.
  2. Keep your garden weed free.
  3. Dig your garden sparingly, preferably in the Autumn or Winter.
  4. Learn to recognise dye plant seedlings.
  5. Use mulch sparingly i.e. only on areas where you intend to plant out other plants. (Mulch supresses seed germination and encourages slugs and snails).
  6. Try and control slugs and snails. (I recommend organically approved slug bait [Iron phosphate] as a last resort).
  7. Water the bare soil if it becomes very dry.

Three varieties of Japanese Indigo Persicara tinctoria

Finally I have managed to sow all three varieties of Japanese indigo at the same time to complete our comparative studies (see blog post). Sure enough, it is possible to tell the difference between the long leaved variety and the broad leaf variety. Even the photos show the slight difference in foliage colour (the broad leaf being a more yellow green) and the long leaf plants are a centimetre or so taller. These plants are about 3 weeks old and grown under identical conditions. The intermediate variety more closely resembles the broad leaf.

Persicara tinctoria

3 varieties of Japanese Indigo at three weeks from sowing.

More Pests

We have found something that eats madder.

Rubia tinctorum pests

This is probably the caterpillar of the Orange Underwing moth, a known pest in the UK which eats a whole variety of plants. So we’re not surprised it’s had a go at our Common Madder. Fortunately there are not enough of them to do any real damage, but they do spoil the appearance of the plants. We can live with that, so no need to take any action.

Suppliers

Rühlemann’s herb nursery has an excellent collection of dye plants and seed for sale and don’t mind sending stuff to other European countries. Their service is excellent.

Poyntzfield Herb Nursery   Scottish herb nursery sells various dye plants and will sell Dyer’s Woodruff root cuttings. Recommended.

References

* Dominique Cardon, Natural Dyes : Sources, Tradition, Technology and Science   . The Definitive reference book of dye plants and dyeing. If you want to know what dye plants are native to the country you live in you will find the information here. A master work, expensive but worth every penny.

Our back garden