How do I grow alstromeria? I have had no luck at all in the past. Thanks,
Thank you for contacting Horticulture Talk on our Facebook page. First of all, let me say, if this seed has given you problems, don’t feel horrible because it is a tricky little seed to be sure!
Sow seed in a 200-cell tray or larger. Cover seed with 0.25 in. (0.6 cm) of germination mix. Water trays thoroughly, to the point of saturation. Make sure seeds remain completely covered after watering. Soil pH should be 5.5 to 5.8 and soluble salts (EC) at less than 480ppm (2:1 extraction).
Stage 1A (7 days): Maintain soil temperature at 72°F (22°C) for 7 days. Place trays in a dark germination chamber. Maintain 100% relative humidity; trays can be wrapped in plastic to achieve this. Keep plugs wet through Stage 1. Ammonium levels should be less than 10 ppm during Stage 1.
Stage 1B (21 days): Transfer plugs to a cool chamber and hold at 42 to 45°F (5 to 7°C) for 21 days. Continue maintaining 100% relative humidity.
Stage 2 (14 days): Maintain soil temperature at 65°F (18°C). Reduce moisture levels once radical emergence occurs. Allow the soil to dry out slightly before watering for best germination and rooting. Keep soil pH at 5.5 to 5.8 and soluble salts (EC) at less than 480 ppm. Begin feeding with 75 to 100 ppm N from 14-0-14 or a calcium/potassium nitrate feed every other irrigation when first leaves are fully expanded. Keep ammonium levels below 10 ppm. Irrigate early in the day so foliage is dry by nightfall to prevent diseases.
Stage 3 (14 days): Maintain soil temperature at 65°F (18°C). Allow soil to dry slightly between waterings to promote root growth and control shoot growth, but avoid wilting completely. Keep soil pH at 5.5 to 5.8 and soluble salts (EC) at less than 480ppm. Feed with 100 to 150 ppm N, using 14-0-14 or other calcium/potassium nitrate fertilizer. Alternate feed with clear water irrigations. Supplement with magnesium sulfate or magnesium nitrate (16 oz./100 gal.), 1 or 2 times during this stage.
Stage 4 (7 days for a 200 tray): Maintain soil temperature at 65°F (18°C). Allow soil to dry slightly between waterings, but avoid wilting. Keep soil pH at 5.5 to 5.8 and soluble salts (EC) at less than 480 ppm. Feed at every irrigation at 200 ppm N with 14-0-14 or other calcium/potassium nitrate fertilizer. If direct sowing into a liner tray such as a 50 or 72 tray, add an additional 2 to 3 weeks. Do not let plugs or liners get rootbound before transplanting to next stage. Rootbound plugs will delay flowering.
The total crop time from sowing for a 200-tray is 9 weeks. If direct sowing into 50 or 72-trays, add 2 to 3 weeks as having more root space will cause them to develop more roots than shoots (proportionately).
Optional Liner Production (50 or 72-cell trays): If not direct sowing, 200-cell plugs can be transplanted into larger liner trays before being potted into final container. This should be done before the 200-cell plugs become rootbound. Maintain air temperature at 60°F (16°C) nights, 65°F (18°C) days. Maintain soil temperature between 50 and 60°F (10 and 16°C). Allow soil to dry slightly between waterings, but avoid wilting. Keep soil pH at 5.5 to 6.3 and soluble salts (EC) at less than 480 ppm. Feed at every irrigation at 300 ppm N with 14-0-14 or other calcium/potassium nitrate fertilizer. Total time from transplanting is 3 to 4 weeks.
Once your plants have gone through the gauntlet of germinating and getting established, you and put them in 6-in. (15-cm) pots or large containers, one plant per pot. Use a well-drained, disease-free, soilless medium with a medium initial nutrient charge and a pH of 5.5 to 6.0. Keep them at 60°F (16°C) at night and at 65°F (18°C) for days. Alstroemeria flower year-round. However, the crop time is 4 to 8 weeks longer when sowing June through December. Allow the soil media to dry out slightly between irrigations. Alstroemeria have very fleshy root systems. Pots should be placed on a surface that allows good drainage to avoid root rot. Feed with 20-10-20 alternating with 14-0-14, at 250 to 300 ppm with every irrigation. Maintain soluble salts (EC) at 765 ppm (using 1:2 extraction). Check EC every 2 to 3 weeks. Leach with clear water if salts rise above 900 ppm.
Good height control is achieved when the plants are grown under the recommended temperatures. If needed, height can be controlled by allowing the plants to dry slightly after the roots have reached the sides of the pot. Height can also be controlled by withholding phosphorous and ammonium-form nitrogen.
Remember these key tips for producing the best-quality plants: Do not let plugs or liners become rootbound, and soil temperature must be kept below 60°F (16°C). If you plan to sell the plants, provide alstroemeria plants with bright, indirect light indoors or partial sun outdoors. Remove spent flower stems by pulling or snapping the stems out of the soil – do not cut the stems. As an indoor pot plant, alstroemeria perform best in bright, indirect light and cool locations. To enjoy alstroemeria outdoors, plant in partial sun and mulch the plants to keep the roots cool. In cooler climates, alstroemeria can tolerate full sun. Remove spent flower stems by pulling or snapping the stems out of the soil –do not cut the stems.
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