Planting asparagus (Asparagus officinalis) is an investment in time, money and space and growing it from seed is more difficult way to propagate it by division. Asparagus is usually grown from roots or crowns which means that only two years rather than three years are needed until the first harvest. Since most vegetables can be harvested the same year they are planted it is difficult for most gardeners to wait two years, let alone three years. The decision to grow asparagus from seed is a personal one and depends on how committed you are to a vegetable garden and how much patience you have.
If you have decided that you do want to try asparagus from seed your next decision is the variety you wish to plant. There can be a big difference between the price for old standard heirloom varieties like Martha Washington and the price for modern more productive hybrids such as Jersey Giant. One hundred seeds of Martha Washington can cost as little as $3.80 while 25 seeds of Jersey Giant maybe $27.00. In addition, the Marth Washington plants self sow and can be used as a source for seed to propagate more plants while Jersey King can not because it is a hybrid and may not breed true. Although bees carry asparagus pollen, cross-pollination is rarely a problem because so few varieties are grown.
Seed should be planted indoors six to eight weeks before the last spring frost date. Direct seeding outdoors should be in spring in the North and all year in the South.
1. Soak seeds for at least two hours and up to two days in lukewarm water to soften the tough seed coat.
2. Immediately after soaking sow one seed per plug, or 2” pot. Cover with ½ inch of fine soil or sand.
3. Provide bottom water to keep soil evenly moist but not wet.
4. Set plugs, or pots in a place where the soil temperature can be maintained at 60 to 85 F to facilitate germination. Seeds usually take between 14 and 21 days to germinate but can take longer. Seventy five percent of the seed should germinate.
5. When danger of frost is past, harden off seedlings and transplant twelve inches apart in rows forty eight to seventy two inches apart. Asparagus transplants easily.
6. Follow directions for planting and maintaining crowns or roots.