- Mar 20, 2018 -
You can plant asparagus in the ground, but it really thrives when planted in a raised bed. This design fits a 2x8 bed, such as our Cedar Raised Beds. this design holds about 14-16 asparagus plants — or "crowns" — planted in a staggered fashion about a foot apart.
IF you love asparagus and want to grow some yourself, waste no time in getting started. Even with the best of care, an asparagus bed won't hit its stride for several years. But once that happens, the bed will produce an abundant crop of spears spring after spring for at least the next 20 to 30 years.
In the old days, gardeners were told to prepare an asparagus bed by digging an 18" deep trench and then backfilling it with a mix of compost and soil. Thanks to plant breeders at Rutgers University in New Jersey and elsewhere, today's improved varieties of asparagus are less work to plant (6" to 12" deep is adequate) and produce almost twice as many spears per plant. The production increases are due to the fact that these hybrids are all-male cultivars, so no energy is wasted producing seeds. They also don't produce baby asparagus plants, which can compete for space and nutrients. So forget about Martha Washington and the old asparagus varieties. Most of the new varieties are also resistant to two common asparagus diseases: fusarium rot and asparagus rust.
Before planting a new asparagus bed, it's critical to eradicate all the weeds and grasses from the planting area — even if this requires a full year of advance preparation. Asparagus plants will not tolerate weed competition. Even though asparagus can sometimes be spotted growing in a ditch among thick grass, the domesticated varieties won't survive. No grasses, no weeds. Period.
Asparagus crowns are usually available just once a year in early spring. So plan accordingly. Once the bed is weed-free, dig a trench about 12" deep and a foot wide. The crowns should be planted at 18" intervals in the bed, so put a shovel of compost and a cup of all-purpose, organic fertilizer in the trench every 18". Rock phosphate, a natural mineral powder, is another good addition. Phosphorus, which promotes strong root growth, doesn't move through the soil as easily as other nutrients. You only get one opportunity to fortify the root zone, so don't miss your chance.