Stop cutting asparagus when most of the new spears come up thinner than a pencil. In a New Brunswick bed that signal matters as much as it does anywhere, because the crowns have to feed the planting for a decade or more. Spears you did cut keep best at 0°C to 2°C (32°F to 35.6°F) in very humid air, standing in water like cut flowers. Below you’ll find the cutoff rule, the storage window, and what a home fridge does to both.
How do you know when to stop cutting asparagus in New Brunswick?
Every spear you cut is a fern the plant never grew, and the fern is how the crown refills its roots for next spring. Early in the season the spears come up thick, because the roots are full. As the reserves drain, new spears get thinner. When most spears are thinner than a pencil, the crown has given what it can, and the next cut would borrow from next year. A few skinny spears among fat ones mean nothing. The majority decides.
Age sets a ceiling on top of that rule. Utah State University Extension has crowns going into 8-inch furrows in early spring, with no harvest until year 3. Then the bed is harvested each year for many years. Taking “just a few spears” in the first two years is the mistake that shortens a bed’s life. The weeks are the longest a season may run. If the spears thin out sooner, stop sooner.
Spring weather in the province varies too much for a calendar date to be reliable. At the Moncton station the average last spring frost is May 23, but that is a midpoint. In one year out of two the last frost comes later. Northern and upland districts run weeks behind Moncton. A frosted spear goes limp and dark, so snap it off and wait for the next one. Watch the bed, because the plants set the schedule.
Once the ferns are up, the bed needs water and attention. Moncton A averages 267 mm (10.5 inches) of rain across June, July and August, and August is the driest of the three at 81 mm (3.18 inches). Those are long-term normals for one station, so a rain gauge on your own plot gives the real number. The loam and silt soils common in the province shed rain fairly quickly, and a hot, dry stretch can leave the crowns short. Summer is also when beetles find the ferns, so keep What Eats Asparagus in New Brunswick, and When handy.
Keeping it, and for how long
The UC Davis Postharvest Technology Center gives the target for green asparagus: an optimum temperature of 0°C to 2°C (32°F to 35.6°F) and an optimum relative humidity of 95 to 100 percent. Its fact sheet adds that high relative humidity is essential to prevent desiccation. Cut spears keep losing water, and the cut end loses it faster than any other part. The full sheet is at UC Davis Postharvest, green asparagus.
What happens above and below the window?
The window is narrow and both edges bite. Warm storage toughens spears quickly, and cold storage that goes a little too far freezes them.
| Temperature | What the spears do |
|---|---|
| Above 10°C (50°F) | Toughening occurs rapidly |
| 0°C to 2°C (32°F to 35.6°F) | Optimum, with 95 to 100 percent relative humidity |
| -0.6°C (30.9°F) or lower | Freezing injury likely: a water-soaked look, then extreme softening |
The target sits close to the freezing edge, 32°F against 30.9°F. A single cold spot in a fridge can ruin spears that are fine a few inches away. The damage shows up on thawing, when the tips and stalks collapse.
How long do cut spears keep?
Any storage duration is a ceiling under optimal conditions, and a kitchen rarely meets them. Cold air at the right humidity slows the aging of a spear. It does not stop it. Spears left on a counter or in a warm car toughen quickly, and the fibers do not soften again in the pot. Cut and eat them as soon as you can. Treat any longer keeping as the best case, available only when the temperature and humidity both hold.
Where in the house that actually is
Which fridge shelf is closest to the target?
A domestic fridge usually runs a few degrees warmer than that optimum, and the door runs warmer still because every opening lets in room air. Keep spears off the door. The best spot is a lower shelf toward the back, where cold air settles. That same spot is also where the fridge is most likely to dip toward the freezing edge, so check it. If it frosts or ice crystals form on the back wall, move the spears forward a few inches. A crisper drawer is the other good choice, because it holds humidity better than an open shelf.
How do you get 95 to 100 percent humidity at home?
A fridge’s air is dry, far from the 95 to 100 percent the spears want. In practice you create humidity around the spears, and the cut ends matter most because they lose water fastest. Stand the butts in an inch or so of water in a jar or tall container. If you skip it, the spears dry out and toughen even in a cold fridge. Drape a loose plastic bag over the tips to hold moisture without sealing them tight. If you don’t have a jar tall enough, wrap the cut ends in a damp paper towel and keep them upright or lying in a closed bag.
Change the water if it clouds, and re-wet the towel if it dries. Keep the tips out of standing water, because they soften when submerged. For anything longer than a day or two, a cold jar and a bag give spears the best chance of staying crisp.
Does the bed need anything after the last cut?
It does, and the first year shows how patient the bed is. The furrow is backfilled gradually rather than all at once. Over the first year that fills the 8-inch trench while the crowns grow upward through the soil. Once cutting begins in year 3, the bed produces for 10 to 15 years.
That span makes the site a long decision. The dominant soil in the province’s agricultural regions is a Podzol, which makes up 46 percent of the mapped surface, followed by Gleysolic. The median surface horizon is a well-drained loam to silt, with 47 percent sand, 16 percent clay and 37 percent silt, and about 3.4 percent organic matter. Utah State University Extension says most soils will do for asparagus provided they are well drained, so the typical ground here starts in good shape. Your plot may not match the median. River bottoms, wet low ground and any soil that a builder has scraped or filled can behave very differently. Check how fast water leaves a test hole before you plant, and read Will New Brunswick Soil Hold an Asparagus Bed for Fifteen Years? for the full picture. If the spot holds water, a raised bed is the way to go. The broader Growing Asparagus in New Brunswick guide covers the rest of the setup.
Common questions
Can I cut a few spears in the first or second year?
No. The crowns are not harvested until year 3. Cutting early costs the bed years of production.
What happens if my fridge freezes the spears?
Freezing injury shows as a water-soaked look that leads to extreme softening. It is likely at -0.6°C (30.9°F) or lower. The spears will not recover, so move the next batch away from the back wall or vents.
Does variety change when I stop cutting?
Utah State University Extension names several varieties, some all-male and some with both male and female plants. Sex is all it says about them. The pencil rule applies to each one.
Can I keep asparagus on the counter in a glass of water?
Water at the cut ends helps, but room temperature is far above 10°C (50°F), where toughening occurs rapidly. A glass on the counter is fine for a short time before cooking. For anything longer, put the jar in the fridge.