Better Management Practices
Site and Conditions
Because of the species' beauty, it is tempting to use madrone in formal landscapes. And its appropriate in some climates because of its drought tolerance. Thinking about the basics of madrone ecology, the conditions where the tree thrives can be relatively defined by the soil type and drainage. Well drained soils are optimal and saturated soils are not not ideal. Some soils retain water and can be improved by adding a looser material such as sand, gravel or light compost. However, organic materials (mulch & compost) should not touch the base of the tree stem or leaves because they retain moisture and will create an environment for Phytophthora or other diseases to spread.
We encourage people to use re-usable or paper bags to collect and temporarily store berries. The fruit respires and storage in plastic bags will create conditions ripe for decomposition.
Seed Collection Time: October - December (depending on latitutde and elevation). The ~1cm wide fruit turns orange-to deeper red colored when ripe.
Seperate fruit from twigs and woody parts. Berries can be dried at room temperature and stored at 34°F (4°C) for at least 2 years, and at 1-4oC for longer periods.
Berry Prep & Seed Extraction
Seeds can can be dried or seed separated from the pulp of fresh or dried berries. To extract seeds from dried berries, berries can be soaked in water (generally overnight). Number of seed per berry ranges from ~2-40. Macerate or blend in water. Dry at room temperature for about 1 week. Separate seed from pulp when dry. This can be accomplished by using compressed air where lighter chaff and berry parts will float off. DIY using hands or toothpicks! Seed can be stored in jars at 34°F.
Cold Stratification & Seeding
Temperate plants often exhibit dormancy, an after-ripening period that is broken in nature by chilling. Dormancy within species can differ depending on which elevation or latitude of mother tree. Breaking dormancy artificially usually leads to increased and more uniform germination and more baby seedlings.
Stratification: cold stratify for 20-90 continuous days at 1 - 2°C to improve germination. At what point is there diminishing benefit from longer stratification period? 2°C (36° F) to 40 days and 60 days can produce good germination.
DIY Cold Stratification
Alternative is to soak the berries in water overwinter and spread the berries by hand on choice sites in the late winter/early spring. This method focuses on quantity and saves some time in the seed extraction and preparation.
Seed-based restoration can be an effective and affordable way to carry out revegetation of an area. Or it can complement planting of seedlings/saplings. Let us know if you have experience with direct seeding! Seed enablement could assist with your endeavor.
Germination: Use sand medium, sow seed 1/16" deep, tamp the soil, keep moist.
Sow in plug trays and top-dress lightly with fine vermiculite. Germinate at 68-80 °F.
Naturally seedlings succumb to drought(soil moisture), fungus, litterfall, and invertebrates. Damping-off fungi (Pythium spp.) can have a large impact on seedlings in the nursery. Optionally, people can drench with a fungicide to prevent damping-off. Fertigate weekly at 100 ppm N to start, building up to 300 ppm N at the end of plug stage.
Transplant to individual containers when large enough to handle. After two months (approx.), transplant plugs into pots for at least one season, after which they are outplanted to the field. Deeper pots can be beneficial to encourage deep roots. This period could be extended to grow the plants out to a more desirable, taller height at outplanting where leaves are up and off the ground and above surrounding vegetation. Seattle Parks has experimented with adding coarse gravel to the top layer of the pot to encourage drainage and air circulation. Some credence is given to transplanting seedling before the third year in pots to avoid transplant shock or to use techniques to ensure the root system is extensive enough to keep up with the needs of the plant. Avoid damage to the plant to assist with recovery of this stressful activity.
Outplanting and Establishment
Encourage air circulation by selecting planting sites on the edges in full sun to partial shade with well-drained soil to minimize fungal diseases. Sun exposure dries the water on foliage quickly, reducing leaf disease. Again, the tree may tolerate, but does not thrive in, waterlogged sites. Infrequent, deep watering if needed so not to facilitate root fungal pathogens. Some site and soil preparation to alleviate compaction can be beneficial. One may think about “companion” plantings of understory species that reflect unique madrone ecology. Planting seedlings/saplings within the root zone of mature madrone or Douglas-fir may enable sharing of mychhorizal fungi. Supplemental watering and weeding may be necessary until root system can enable robust vegetative growth.