Asparagus Should Be Cut Below the Soil Surface

Q. I have a raised bed (5 x 10 feet) dedicated to asparagus. The yield has been magnificent. However, the plot has gotten so overgrown with old asparagus stumps that I have had to totally remove and replace all the soil because cultivation was impossible. My question is how long can an asparagus garden last without being so impacted that it must be replaced; or, is there a way to deal with spent stumps annually to prevent this problem.




Purple passion asparagus with some rabbit damage. Rabbits love the
higher sugar content of Purple Passion

A. Asparagus rhizomes are normally planted about 12 inches below the soil surface. If started from seed, the seed is planted in a trench and backfilled as the plants grow so that the developing rhizomes are still at about 12 inches deep. 

Asparagus crown for vegetative propagation. Selecting crowns that
are male will guarantee a male crop. Spears emerge from the top
where the fleshy roots come together

When this is done the spears can be harvested by cutting below the soil surface with a knife so that these "stumps" don't stay on the surface. If you harvest the spears by "snapping" them or breaking them above the soil surface then you will get these woody stumps remaining above the soil surface and they interfere with future harvesting.

So, in short, if you can harvest by slicing with your knife an inch or so below the surface I think this will stop your "stump" problem. The woody part is cut off after harvesting during food preparation. The woody part should compost fairly easily.

Snapping off spears will cause the spear to break just above the woody portion. Nice
for the kitchen but leaves a "stubble" behind in the asparagus bed

Recent research has pointed out that asparagus spears can be harvested anytime the spears are pencil diameter or larger five inches above the soil level. Smaller spears should be left to grow into fernlike growth to replenish the roots for upcoming seasons. The plant is still expanding its root storage system and excessive removal of spears weakens the plants. However, there is a market that has emerged utilizing these very thin spears.

In commercial operations all spears are harvested cleaning the entire bed and spears are allowed to grow to ferns only after the harvest period. An asparagus plant will yield an average of 8 to 12 spears per year before the roots need to be replenished by letting the spears develop into ferns.

Harvest spears by cutting or snapping. To cut a spear, run a knife into the soil at the base of the spear and carefully sever it. Because the spear cuts below the point where fiber develops, it becomes necessary to remove the fibrous base from the tender stalk. Most homeowners and some small scale growers prefer to snap the spears. This eliminates any woody growth on the harvested spears. This does however leave a "stubble" on the surface that can make harvesting more difficult.


To snap a spear, grasp it near the base and bend it toward the ground. The spear breaks at the lowest point where it is free of fiber. Stalk diameter is not a good indicator of proper maturity and associated tenderness. Hydrocooling, or plunging freshly harvested spears into cool, clean water is strongly recommended.

Commercially, asparagus is graded by class (US Number One and US Number Two which are based on straightness and head compactness) and by diameter 5 inches from the tip (see table) according to USDA standards for canning asparagus.