Preparing the Asparagus bed ready for many years of production
If your bed is not ready, heel in your asparagus with moist medium in a freely draining pot, bucket, tub or what-have-you in a sunny cool frost free area until you are ready to plant. If weather is favourable, seat them in deep pots where the roots can continue to grow and plants to thrive while you are getting the bed prepared.
Cultivate soil so it is weed free. Sift (if your soil is like ours…pick out the rocks) and amend so it is well draining via adding sand if it is too heavy or organic matter if it is too sandy. AND the site should be well draining. If you make a trench and rain does not drain freely, you might have to consider another site or consider a slightly sloped area.
Dig a trench 18cm wide and 20-25cm deep. Amend the soil by mixing in 500 g of equal blend of rock phosphate and green sand (Gaia Green 4-4-4 is good too) to each full wheelbarrow of sifted soil to improve plant production and vigor. This is the optimum depth for seating roots as asparagus spears will be thin if planted shallow and production will decrease at deeper depths.
Crowns should be spaced 30cm apart, and settled in the soil so that the tops of the crowns are 15-20 cm below the top of the trench. If using “A” via spreading/splaying the roots, seat the crown on a small cone of soil for optimum root-soil contact. Spread the crowns out on the bottom of the trench. If using “B” make a slope with the crowns seated at the top.
When you are happy how the crowns are seating, add the contents of the mycorrhizae packet into a full watering can. Mix well and sprinkle ½ over roots. Cover with 3cm of amended soil, firm soil with a fine shower of remaining mycorrhizae water. Add another 3cm of amended soil and firm again with a fine shower of regular water. Do not drench. Again, top with 6 cm of amended soil and use a fine shower of water. Crowns should not be visible. As the plants develop and send out small shoots and ferns, fill in the trench gradually with amended soil or well-aged compost but never cover the emerging tips. Trench planting is best as those who grow them for a living know that deep planted asparagus crowns are more productive.
Never add compost or fertilizer until plants are growing and continue to fertilize during the time the trench is being filled. Again use greensand, rock phosphate and, if you wish, a dilute solution of soluble kelp powder.
Keep weed free via mulch during the dormant season. Carefully pull weeds during the growing season as not to damage asparagus shoots or ferns.
Amend bed every year with compost and mulch. Do not harvest until the 3rd year so the crowns are super robust to provide spears without compromising plant health and vigor. This means the ferns must remain intact all season long and only be cut down to ground level in the early spring before new spears start to emerge (April?).
Seating your crowns in the prepared trench
Okay, now what? Be patient. All asparagus whether one year, two or three year old roots, take 2-3 years gaining strength to reach a full yield and, thereafter, produce spears for the next 10-20 years! This means that companions for asparagus must like sun exposure and be able to work around the semi-permanent asparagus.
Harvest Expectations/Schedule
| Time of year | Year | Garden task |
| Spring | 1 | Plant crowns in the prepared site |
| Spring | 2 | Don’t harvest |
| Spring | 3 | Only Harvest finger thick spears for 4 to 6 wks |
| Spring | 4 to 20 | Harvest spears for 6 to 8 wks |
Companion planting: getting the most out of the garden
Tomatoes are excellent companion plants as they are rich in solanine a natural repellant to asparagus beetles which feast on the tender shoots and fronds of asparagus plants. In turn, asparagus protect tomatoes from root-knot nematodes. Plant tomatoes alongside the asparagus
Basil and parsley deter asparagus beetles. Plant them beneath the arching asparagus fronds. They will natural companion plants for tomatoes and will also deter tomato hornworms if tomatoes are part of the companion planting.
Coriander, comfrey, and dill are particularly good at repelling spider mites and aphids.
Aromatic marigolds and nasturtiums are powerful natural insect repellants. Dense plantings can deter weeds.
Other companions: lettuce, spinach, calendula
Perennial companion plants are: thyme, sage, oregano, strawberry, rhubarb, comfrey, and horseradish. Strawberries are excellent companion plants.
D Never plant potatoes or Allium of any sort near or alongside asparagus. D