Here's a guide to planting Solidago speciosa (Showy Goldenrod) seeds in the USA:
Site Selection
Sunlight: Showy Goldenrod thrives in full sun, needing at least 6 hours of direct sunlight daily.
Soil: Well-drained soil is essential. It can tolerate a variety of soil types, including sandy, loamy, and clay soils, as long as drainage is good. Avoid areas where water tends to stand.
Space: These plants grow 1-3 feet tall and can spread via rhizomes, forming clumps over time. Provide adequate space for their mature size.
Direct Sowing Outdoors
Fall Planting: Fall is the ideal time to sow seeds directly outdoors. This allows for natural stratification over the winter.
Preparation: Clear the area of weeds and debris. Lightly loosen the top layer of soil.
Planting Depth: Sow seeds very shallowly, barely covering them with a thin layer of soil or sand, as they need light to germinate.
Watering: Keep the soil consistently moist, but not soggy, until seedlings emerge.
Spring Planting: Spring sowing is also possible.
Preparation: Prepare the seedbed as described above.
Planting Depth: Sow seeds as described above.
Watering: Water regularly until seedlings are established.
Starting Seeds Indoors
Timing: Start seeds indoors 8-10 weeks before the last expected frost in your area.
Stratification: Showy Goldenrod seeds benefit from cold stratification. This improves germination rates.
Mix seeds with slightly moistened sand or vermiculite.
Place the mixture in a sealed plastic bag.
Refrigerate for 4-6 weeks.
Planting:
Use a seed starting mix. Sow seeds very shallowly in seed starting trays or pots.
Keep the soil moist and provide warmth (70-75°F) for germination. Light is important.
Transplanting: Once seedlings have a few sets of true leaves and the weather has warmed (after the last frost), transplant them outdoors. Harden them off gradually before transplanting.
Maintenance Tips
Watering: Once established, Showy Goldenrod is relatively drought-tolerant. Water deeply but infrequently, allowing the soil to dry out somewhat between waterings.
Fertilizing: They generally don't need much fertilizer. A light application of a balanced fertilizer in spring is sufficient.
Pinching: Pinching back the tips of stems in late spring can encourage bushier growth.
Staking: Usually not necessary, as they have strong stems.
Deadheading: If you want to prevent self-seeding (it can spread), remove seed heads before they mature.
Dividing: Established clumps can be divided every few years to control spread and rejuvenate plants.
Invasiveness
Showy Goldenrod is native to North America and is not considered invasive in the same way as some non-native plants. However, it can spread through its rhizomes and self-seeding, forming colonies over time. If you want to restrict its spread, remove seed pods before they mature and divide clumps regularly.
Additional Notes
Scarification: Scarification is not usually necessary for Solidago speciosa seeds.
Pollinators: Showy Goldenrod is a great late-season nectar source for butterflies, bees, and other pollinators.
Deer Resistance: Goldenrods are relatively deer-resistant.
Important Considerations
Good drainage is key to success.
Provide adequate spacing to allow for air circulation.
With these guidelines, you should be able to grow beautiful Showy Goldenrod in your garden!
