100% Pure Natural Onion Seeds

Quality: Very Good
Purity: 100%
Uses: Food
Cultivation Type: Common
Country of Origin: India.

Onions prefer dry hot summers and develop best in sandy or silty loam soils with high water-holding capacity and a consistent water supply. They require high nitrogen and phosphorus, but excess nitrogen can be detrimental. Since onion seed populations need to be in the range of 120-200 plants, a greater number of bulbs will be needed the first year to account for any selection and bulbs that deteriorate during winter storage. A good number of onion plants for the first year might be 250-300. Plant transplants 3-4 inches apart to provide room for bulb formation. After the bulbs have formed, selections can be made based on important traits for the population. After 50% of the tops have fallen over, knock the rest down and wait a few days before digging the bulbs up and windrowing them for 1-2 weeks. Turn bulbs to avoid sunburn. The best onion bulbs should have their tops cut and be stored in burlap sacks in a humid (65-75% relative humidity, RH), cool (32-34A F) area with good air circulation.


Figure 1. Onions just before harvest. When 50% of the tops have fallen, knock the others over.
Year 2: Producing the onion seed
Since onion is highly outcrossing and insect-pollinated, it should be isolated from other onion varieties by at least 0.5-1 mile. More distance is necessary if varieties are different colors and/or different shapes. Select onion bulbs that have no disease, sprouting, or elongation after storage for planting. If selecting for single centers or other internal qualities, cut the top third of each bulb off horizontally to evaluate internal characteristics before planting. Allow selected bulbs to sit and heal over for 2-3 days before transplanting.


Figure 2. Onion umbels drying on landscape fabric.
At least 120 plants should be used to maintain population integrity. The bulbs should be planted 12 inches apart in rows that are 18-24 inches apart. Plants may need to be staked to avoid falling over or to protect them from being knocked over by wind. Clear, warm weather is beneficial for pollination, and temperatures between 65A F and 95A F are best for seed set. Overhead watering can increase the potential for disease and should be avoided during flowering and seed set. Approximately 3-4 weeks after fertilization seed enters the a dough stage.a Three more weeks after that the seed should be mature. Begin harvesting once the capsules are open and the black seeds are visible. Cut seed heads 4-6 inches below the umbel and lay on landscape cloth. Allow to dry for up to 2 weeks and turn to avoid sunburn if in direct sun. It may take 2-3 weeks to harvest all bulbs as flower maturity can be variable. Thresh the seed by rubbing by hand, through screens, or combining. A combination of winnowing and screening will be needed to get the seed fully clean. For lots with low germination or persistent bracts and stems, flotation may be a useful technique as the bracts, stems and immature seeds will float and can be easily skimmed off. If flotation is used, dry the seed immediately and do not allow seed to be immersed in water any longer than is necessary. In other words, dona t start the process unless you intend to finish it.


Figure 3. Floating onion seed. Clockwise from the top left: Add water and pour off any floating debris or light seed. Be prepared with a strainer to catch heavier seed.

Figure 4. From left to right: Continue pouring until all light material is gone. Pour final water out, catching seed in a strainer with holes smaller than the seed.
Onion seed dried to 6.5% moisture and stored under favorable conditions (40-60A F and <40%RH) will last 1-2 years. Properly dried seed that is stored in a freezer will keep indefinitely.


Figure 5. Drying onion seed after floatation.
Selection and Variety Improvement.