Great Valley Gumweed (Grindelia camporum)

For those in semi arid areas of the western United States this is a wonderful perennial plant that can remain in a garden for many years with little maintenance and water use. For the rest of the country it's mostly grown as an annual to enjoy the lovely yellow flowers and harvest the sticky gummy leaves and buds for medicine. Gumweed likes poor soil and full sun. It does not do as well in areas that have a great deal of rainfall during the summer months and certainly struggles in the hot humid south. For those with reasonable rain and hot weather it can be a delight for the garden as an annual. If your zone is warmer than 6b it may remain as a perennial but above that it does not tolerate the winter. It's easy to grow however and needs little maintenance, producing lovely bright yellow daisy like flowers from late spring until late fall if plants have been started indoors to give them a head start. Due to the sticky gummy leather like leaves wildlife don't eat it but pollinators love the flowers especially bees and butterflies.

Native American perennial plant in the sunflower family native to central California. This is the largest of the gumweed family of plants reaching as much as 8 feet (2.4 m) in height although it is usually much smaller often only reaching 1-3 feet (30.5-91 cm). It dies back to the ground in winter growing again from perennial rootstock in mid spring. Stems are stiff and hold bluish green lance shaped leaves that are alternate, stalkless with strongly serrated margins growing up to 2.5 inches (6 cm) long and 0.5 inches (1.3 cm) wide and dotted with little stalked glands that produce a sticky resin. They have a bluish tinge and are thick, leathery and quite sticky. Stalks are much branched with larger leaves on the main stem and smaller ones as the branches split off at each leaf node. In mid spring flower buds appear as shaggy green globes which exude a sticky white latex as they mature. Just before opening the latex dries up and the yellow daisy like flowers open with heads up to 2 inches (5 cm) across. These are composed of up to 40 long thin oval petals surrounding a central disk composed of dozens of individual tiny tubular flowers that open from the outside towards the center. over a period of many days. Below the flower is a whorl of sticky green bracts with long thin tines. Flowers bloom for many days and are prolific arising from each leaf bract so bloom time can last for many months. Flowers are followed by small brown wind borne seeds. The whole plant has a distinctive resin like aroma.
While some sources state it's hardy to zone 7 this is dubious and more likely to be 8b although its may be possible to sustain it in 7b with heavy mulching and mild winters. In warmer areas 9 and more it will sustain as a woody sub shrub while all other areas it acts more like a herbaceous perennial dying back every winter. While some sources state it can tolerate down to between 14-23F (-5 and -10°C) we have not found that to be true. Plants in zone 7a do not survive the winter outside and it rarely gets as cold as 14F.

Growing Great Valley Gumweed (Grindelia camporum) from Seed.
Easily grown from seed; only very lightly cover seed. Germination takes 2-3 weeks at around 50-60F (10-15.5 C); warmer temperatures often reduce germination rate unless pre treated at around 45 F for at least 8 days. Keep temperatures under 70. Sow in small pots or plug trays for best results. Transplant when large enough to handle and grow on in small 3 inch (7.5 cm) pots until large enough to transplant.
In zones 8b and warmer can be direct seeded in early spring. This method is not recommended in cooler zones as plants will need to be grown as annuals. For more information on growing from seed see our General Growing Instructions.

Care will depend on location. In warm zones (8b and warmer) seeds can be direct sown and plants will grow as sub shrub perennials.
In 7b-8a plants should overwinter outside but mulching is recommended to help through any cold spells.
In 7a and above this plant is grown as an annual unless it is grown in pots and brought inside during the winter months.

Light. In all cases gumweed requires full sun for good growth. Plants will become straggly otherwise.
Soil. Prefers a light well drained soil. Does very well on poor soils with few nutrients, sandy soils are preferred but will grow on most kinds but not waterlogged. Do not add organic material or enrich soil. It is very salt tolerant so is good for road edges and shore locations.
Water. In its native habitat gumweed tends to grow in ditches and bordering wetlands so it does require moist soil for best results. However these areas also tend to lack summer rains so it's used to drying out during those months so it becomes fairly drought tolerant and some sources even suggest that summer watering can reduce the life span of the perennial. If growing as an annual this should not be an issue but for the most part extra water should not be required during the summer months unless there is a prolonged drought. When this occurs gumweed tends to defoliate and wait for rains to return, adding a little extra water at this time will sustain plants especially if growing as an annual.

If started indoors early enough plants will grow to a reasonable size and flower in the first year from seed. They will not reach the size of a perennial plant as some other summer only grown perennials do but it is sufficient to enjoy the flowers and harvest if desired. To obtain larger plants in cooler zones growing them in pots and bringing them into an unheated but attached garage or a greenhouse in the winter months is required.

Gumweeds do well as pot plants and will increase in size every year. During the winter months keep the soil moist but not wet. If plants die down to the ground they can be stored away from windows and light. If leaves remain try placing them near a window if possible. Bring pots out again after danger of frost has passed.

Flowers are very popular with butterflies, native bees, honey bees and other pollinators. they produce reasonably high levels of pollen and nectar throughout the flowering season.

Harvesting seems to depend on the concentration of gum required along with other phytochemical compounds. Some prefer to harvest only the buds when they are at the white sticky stage. Others like to use the whole leaf, and the buds, some use the flowers too. Thus harvesting may be throughout the growing season. For those with easy access harvesting just the buds may be possible but it's a slow, tedious and very sticky process which is most likely why most herbalists and preparations use the leaves as well as the flower buds and possibly the flowers too.

None

Has long been used by Native Americans for many issues and was so effective that it was adopted by early western medicine in California. Its main use today is for treating respiratory issues most commonly bronchial asthma, bronchial catarrh and whooping cough as its active compounds reportedly desensitize the bronchial nerve endings and decrease heart rate, which lead to easier breathing. The active compound is excreted through the kidneys where it can cause some irritation which makes it beneficial in treatment of cystitis.
Externally the leaves and flower heads are boiled to make a strong tea that is used to treat dermatitis caused by poison oak, as well as poison ivy rash, wounds, burns, boils, eczema and sores. Either tea or made into a poultice its mild analgesic properties are said to be beneficial when applied to sore muscles.
The herb is contraindicated for patients with kidney or heart complaints

The sticky aromatic gum exuded by the plant are almost identical to rosin found in coniferous trees but is far less expensive to extract with less water demands so it considered as a use in a variety of industrial applications such as rubber production, synthetic fuels, paints, varnishes, lacquers and adhesives.
Both green and yellow dyes are obtained from the flowering heads and pods.

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Synonyms: Grindelia robusta, Grindelia procera