May 4, 2019
When you were a child, you likely heard tales of legendary seed propagators. One such early horticulturalist specializing in native plants of California was Theodore Payne. In 1915, he planted the California Wild Garden in Los Angeles. At the entrance were masses of yellow daisies, tidy tips and sticky monkey flowers. Further on, garden color transitioned to the blues of heliotropes, gilias, penstemons and lupines followed by orange poppies. Today, that garden is a sports arena but Payne’s vision lives on in several beautiful gardens, including the Santa Barbara Botanic Garden.
Learning to propagate native plants beautifies our gardens, supports butterflies, birds and pollinators, and reduces water use, carbon footprint, pesticide use and even maintenance. The three methods of propagating include seeds, cuttings or division. Seeds are the basic biological reproductive unit of plants. When the seed imbibes water, dormancy ceases and germination begins proceeding with proper temperature and oxygen. Some seeds have impermeable seed coats variously requiring scarification, winter chill, heat and even fire to break dormancy. The seeds of many native annuals like California poppies and Clarkias can be successfully sown mid-fall with no pretreatment, and germinate during the cool rainy season bursting into bloom in spring. To sow native seeds, scratch the surface of the soil with a rake, generously sprinkle seeds in drifts and cover with a thin layer of compost. Water gently and regularly never allowing the soil to dry out completely.
Perennial natives like lupines, penstemon and seaside daisy can be propagated by seed, division and cutting. To propagate by seed, check first if germination requires pretreatment. For example, fresh seeds of perennial sky lupine require no treatment whereas its stored seed germinates best with scarification of the seed either by light sandpaper rub or hot water soak for 12 to 24 hours. Seeds should then be planted immediately. Clumping plants like seaside daisy can be propagated by division every three years in autumn when the plant is dormant.
To propagate by cutting, select perennials like penstemon and after bloom period, take a cutting about 4 inches long from the soft top growth just below a leaf joint. Trim all but three leaves and root in water or sterile soil that is both water retentive and well aerated.
To collect seeds of native plants, watch for several signs signaling it is time to collect. When the seed comes away from the flower easily or pops out of the seed pod, it is usually ripe. Some natives like Clarkias, drop a few seeds a day. Others, like lupines, release seed with a pop as soon as the seed capsule matures. When seeds are in a pod, they are ripe when you shake the pod and hear a rattle.
Most natives have produced viable seed before the first fall-winter rain arrives. Gardeners come to appreciate variations in seed production as survival strategies to be observed with delight; yet another element of the beautiful show put on by native plants.
For plants that fling their seed, harvest the flower and place the bloom in water inside a paper bag folded shut until all the seeds have popped out. For native plants forming seeds in seed heads like seaside daisy, harvest the flower and place in a paper bag until seeds drop. The final step before storage is to clean your seeds by removing the chaff or dry plant material. This helps prevent seed decay and lessens the chance of spreading pathogens.
Store your seed in labeled paper envelopes in a cool, dry place. Remember you need permission to collect native plant seed off your property. On public lands, you need a permit. National parks and California state parks all ban collecting plant material.