Can asparagus spears regrow after cutting?
Written by
Julia Anderson
Reviewed by
Prof. Samuel Fitzgerald, Ph.D.Asparagus spears regenerate after cutting because the plant's crown retains stored energy, but only if you follow strict collecting protocols. I ignored this advice last year and overharvested 90% of my spears, which weakened my plants for the next two seasons. Always leave 30% of the spears unharvested so that they can develop into photosynthetic ferns that can recharge the roots of the asparagus plant. These leafy tops produce starch, which can be used to support the next year's crop as well.
Fern Development Phase
- Allow ferns to grow 4-6 ft tall
- Do not prune until foliage yellows
- Apply 10-10-10 fertilizer monthly
Winter Preparation
- Cut yellowed ferns at soil line
- Mulch with 6" straw before frost
- Check for beetle eggs under debris
Use sanitized, sharp knives. You should cut the spears cleanly. Ragged cuts invite disease. If you are cutting fibrous stems, use a serrated knife. It is best to harvest in the morning after the plants have rehydrated overnight. You never want to get cut the spears below a ½" (1.3 cm) diameter. They will not have energy reserves below that size.
Overharvesting
- Cutting >70% of spears starves roots
- Harvesting beyond 8-week window
- Removing thin spears (<⅜") prematurely
Tool Errors
- Using dull shears that crush stems
- Failing to disinfect blades between plants
- Cutting above soil (snapping preferred)
A crown in healthy condition will regenerate spears for 15+ years, as long as it is managed properly. My oldest bed is 12 years old and still produces more than 50 spears/plant/year. Prioritize crown health above short-term yields, the ferns that you don't harvest today become tomorrow's asparagus shoots!
Read the full article: How to Grow Asparagus: Expert Tips for Perennial Success
