Jeannet Leendertse forages rockweed, a native seaweed commonly found on the northern Atlantic Coast to make vessels. Rockweed is a naturally occurring perennial. She has learned from experts—associated with Rockweed Coalition—to responsibly harvest this material, by leaving the holdfast and at least 30 inches of the rockweed intact. Jeannet Leendertse uses waxed linen to construct her baskets, and incorporates beach combing finds like driftwood.
Seaweed: Ascophyllum nodosum
Ascophyllum nodosum, also called rockweed, kelp and egg wrack, is one of the most common species of brown algae, or seaweed. It is harvested for use in alginates, fertilisers, and the manufacture of seaweed meal for animal and human consumption. It is commonly used to package seafood as well. It is found in the intertidal zone on the north-western coast of Europe (from Svalbard to Portugal) including east Greenland and the north-eastern coast of North America. It grows on available hard surfaces, like rocks.
The regulations for harvesting vary per region. It is a prevalent perennial which regenerates quickly, but nevertheless care should be taken when foraging. Choose areas where it is abundant, and leave the algae’s holdfast and at least 50 cm intact.
Once foraged, the rockweed is best kept in cold sea water. Replenishing the seawater on a regular basis extends its life. Jeannet Leendertse uses a coiling technique and waxed linen or hemp to sew her biodegradable vessels. When wet, the seaweed is gold to green, rubbery, and pliable. When dried, it turns a dark brown or black, and becomes hard and somewhat brittle.
Washed up dried rockweed can be foraged as well. The plants naturally colourful hardened dried air bladders can be used in a bead-like manner.
Rockweed can be composted directly and will improve soil consistency and water retention in sandy or grainy soils.
Note that in some countries, the property owner's permission is needed to legally forage. This may also apply to rockweed.