Since all the books I have that relate to dye plants cover guidelines for gathering I should probably mention the subject here.
From Dyeing with natural materials (Los Aravas Spinners and Weavers Guild, Inc):
When gathering dye plant materials, please remember the importance of seeking permission when gathering on other than your own property. Sources for plant material other than from garden or field might include nursery beds, botanical gardens for the really unusual, or the grocery store. It is always wise to think about the environment when collecting material for your dye pot. Some of the Southwests ecology zones are very fragile and need a long recovery period. We all need to help ensure that local plant populations do not become extinct due to over collection. The recipes we have included here do not utilize any plants that are listed as sensitive species by the U.S. Forest Service. p.6
Ive concentrated on plants that are often considered weeds, are in my backyard, and ones that are going to be mowed down or tossed out. Roadside Fennel (by the freeway, along the road in Topanga Canyon), Oxalis, etc are extremely hardy although I do think it is a good habit to cultivate of leaving enough for the plant to recover and reseed itself. Ironically Ive noticed the best patches of Fennel are often on the most pedestrian inaccessible sides of the Pacific Coast Highway and reaching them would require sprinting across multiple lanes of traffic. Don’t do that either.
So with this in mind, one should avoid trespassing, being mowed down by oncoming traffic (while trying to get to the perfect stand of what-ever, picking anything endangered and over picking in general. Since most dye plants involve a significant ratio of plant to fiber it doesn’t hurt to use stuff that will be tossed out, among my favorites are onion peels (yellow to orange), eucalyptus leaves piling up on the car (sort of red), lawn grass (yellow to green), etc.
Fennel (Foeniculum vulgare)
(Note: for the best search results use ‘foeniculum vulgare’.)
Part of the plant used for dye: flower heads
fiber: wool (It could be me but I can’t get this to work on cotton)
Proportions: 1:4 (fiber:plant)
The first dye plant that I ever tried working with was Fennel. A lucky choice since Fennel (unlike the Avocado pits from hell) has always given me a fairly consistent yellow and provided a pretty good first-time experience with plant/vegetable dyes.
Fennel is one of those wonderful multi-use herbal/dye plants that are often bad-rapped as noxious weeds prone to taking over a garden, city block, etc. In my tiny corner of Southern California (Los Angeles) this doesn’t seem to be the case and my own transplanted fennel plants are quite well-behaved.
I have gathered from the local Smart-and-Final parking lot, Topanga canyon, and patches next to the freeways (public areas) and eventually transfered some smaller plants to my garden.
Nature’s Colors (Ida Grae) describes using Fennel fresh, 4:1. It also appears to work dried.
That is another thing I’ve found about working with dye plants vs synthetic dye. You work on the plant’s schedule not your own. When its ready you had better be there with properly soaked fiber and not the next day at which point it may be past the point of giving up good dye, have been stepped on or eaten. The only way around this is to try drying and saving. Fennel seems to work.
The amount of mordant to use is calculated by the weight of the fiber. A wonderful booklet published by Las Aranas Spinners and Weavers Guild, Dyeing with natural materials has an excellent chart and information about safety (the poisonous stuff) and disposal.
My other standard reference is always Nature’s Colors by Ida Grae. (<- I believe this one is out-of-print but findable places like abebooks or amazon used.)
The ubiquitous baby blankets have been completed up to the borders and may even be finished before a) the twins go off to college or b) by their first birthday. I’m aiming for the latter with a couple of weeks to go.