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 simply 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. That’s the rule, period.
You will also want to add some mycorrhizal fungi to the beds at this time. I purchase mine from David and Teresa Steinbrunner organic landscaping advocates and founders of www.wildrootorganic.com. I can not recommend their product strongly enough! Order some today, you'll be glad you did.
If grasses or other perennial weeds get established in an asparagus bed it is almost impossible to reclaim the planting. So, keep your asparagus bed well-mulched from the start, using shredded leaves, straw, or my personal favorite; crushed pecan shells. For the first couple years, weed often and carefully — asparagus roots are near the surface and can be damaged by weeding tools. Don't interplant other vegetables in the same bed. Asparagus hates competition of any kind.
To keep your asparagus bed productive, don't be greedy. The first year after planting, you can harvest a few spears from each plant. Pick for about two weeks and then stop so the fronds can unfold and begin feeding the root system. Harvest for three weeks the next year, and four to six weeks after that. Pick too much, and your plants will not be able to develop the strong root system and energy reserves they'll need to produce an abundant crop of spears the following season. Remember, these plants will produce for 20 to 30 years if you treat them with TLC during their first few years. Getting less now means getting much more later so take the long view here.
The diameter of the spear has no bearing on quality. Spears should be harvested when they are 5" to 7" high and before the tips begin to loosen. Once the tips loosen, the spears become tough and fibrous. To harvest spears, cut or snap them off just above the soil level. Leaving a stub causes no harm to the plant. Once the bed is well-established, harvesting can continue until the bed yields only skinny spears that are less than a half inch in diameter.
Asparagus is a marvelous garden veggie, it produces for years and is packed full of all kinds of nutrition but the nutritional value of this springtime favorite fades fast after it is picked. Just another great reason to grow it instead of buying it in the store! I love steamed asparagus with a drizzle of extra virgin olive oil and some garlic. I put the steamer on and then go pick the asparagus, it doesn’t get more delicious or nutritious than that!