Pennsylvania asparagus roots establish most effectively in April when soil temperatures reach fifty degrees. The best time to plant asparagus in Pennsylvania depends on your specific region, but aiming for mid-April to early May gives your crowns the best start. Asparagus is a perennial crop that can produce for 15–20 years, so getting the timing right matters.
Planting too early risks frost damage to tender roots. Planting too late means less time for roots to develop before summer heat. In Pennsylvania, you have a narrow window to get it right.
Best Time To Plant Asparagus In Pennsylvania
The ideal planting window for asparagus in Pennsylvania runs from April 1 to May 15. This timeframe works for most of the state, from the southeastern counties near Philadelphia to the northern tier near the New York border.
Soil temperature is your best guide. Asparagus crowns need soil at least 50°F (10°C) to begin root growth. You can check with a simple soil thermometer inserted 4 inches deep. If the soil is still cold and wet, wait another week.
Regional Differences Across Pennsylvania
Pennsylvania spans USDA hardiness zones 5a to 7b. This affects your planting calendar significantly.
- Southeastern Pennsylvania (zones 6b–7b): Plant from late March to mid-April. Soil warms faster here.
- Central Pennsylvania (zones 6a–6b): Plant from early April to late April.
- Northern and mountainous areas (zones 5a–5b): Wait until late April or early May. Frost can linger into May.
- Western Pennsylvania (zones 5b–6a): Plant from mid-April to early May.
If you live in Erie County or the Poconos, you are in the later planting group. Check your local frost dates before planting.
Why Spring Planting Works Best In Pennsylvania
Fall planting is possible in warmer climates, but Pennsylvania winters are too harsh. Freeze-thaw cycles can heave crowns out of the ground. Spring planting gives roots time to establish before winter returns.
Pennsylvania’s spring weather is unpredictable. You might have a 70°F day followed by a frost. That is why soil temperature matters more than the calendar date.
Preparing Your Asparagus Bed
Before you plant, prepare the bed properly. Asparagus lives for decades, so you cannot move it easily later.
Choosing The Right Location
Pick a spot with full sun—at least 8 hours daily. Asparagus needs good drainage. If your soil stays wet, build a raised bed.
Avoid planting near trees or large shrubs. Their roots compete for water and nutrients. Also avoid low spots where frost settles.
Soil Preparation Steps
- Test your soil pH. Asparagus prefers 6.5 to 7.5. Add lime if your soil is too acidic.
- Remove all weeds, especially perennial ones like quackgrass. Weeds are hard to control once asparagus is planted.
- Dig a trench 12 inches wide and 8–10 inches deep. Space trenches 4–5 feet apart.
- Mix 2–3 inches of compost or well-rotted manure into the bottom of the trench.
- Add 1–2 pounds of 10-10-10 fertilizer per 100 square feet, mixed into the soil.
Let the prepared bed settle for a week before planting. This prevents air pockets around the roots.
Planting Asparagus Crowns Step By Step
Buy one-year-old crowns from a reputable nursery. They should be firm and not dried out. Avoid crowns that look shriveled or moldy.
When To Plant Crowns
Plant crowns as soon as you get them, ideally within 24 hours. If you must wait, store them in a cool, damp place like a refrigerator. Keep them moist but not soaking.
The best time to plant is on an overcast day. Direct sun can dry out roots quickly. Plant in the late afternoon if possible.
Planting Technique
- Soak crowns in water for 1–2 hours before planting. This rehydrates the roots.
- Create a small mound of soil in the bottom of the trench, about 2 inches high.
- Place the crown on top of the mound. Spread the roots out evenly over the mound.
- Cover the crown with 2 inches of soil. Do not fill the trench completely yet.
- Space crowns 12–18 inches apart within the trench.
- Water thoroughly after planting.
As the spears grow, gradually fill in the trench over the next few weeks. This encourages deeper root growth and stronger plants.
Caring For New Asparagus Plants
First-year asparagus needs consistent care. Do not harvest any spears the first year. Let them grow into ferns to feed the roots.
Watering Requirements
Asparagus needs about 1–2 inches of water per week during the growing season. Pennsylvania usually gets enough rain in spring, but monitor dry spells.
Water deeply rather than frequently. Shallow watering encourages shallow roots. Use drip irrigation or soaker hoses to keep foliage dry and prevent disease.
Weed Control
Weeds are the biggest problem for new asparagus. They compete for water and nutrients. Mulch with 4–6 inches of straw or wood chips to suppress weeds.
Hand-pull weeds carefully. Asparagus roots are shallow and easily damaged by hoeing. Do not use landscape fabric; it interferes with spear emergence.
Fertilizing Schedule
- Early spring: Apply 1 pound of 10-10-10 fertilizer per 100 square feet before spears emerge.
- After harvest: Apply another round of fertilizer to support fern growth.
- Late summer: Avoid fertilizing after August. New growth needs time to harden before frost.
Use a balanced fertilizer. Too much nitrogen produces weak, spindly spears. Organic options like fish emulsion work well.
Harvesting Asparagus In Pennsylvania
Patience is key. Do not harvest the first year. The second year, you can harvest for 2–3 weeks. By the third year, you can harvest for 6–8 weeks.
When To Start Harvesting
Harvest when spears are 6–8 inches tall and the tips are still tight. Snap them off at ground level. Do not cut below the soil line; it damages the crown.
In Pennsylvania, harvest typically starts in late April or early May for established beds. The exact timing depends on spring weather.
How To Harvest
- Check the bed daily once spears appear. They grow fast in warm weather.
- Snap spears by bending them near the base. They break naturally at the woody point.
- Stop harvesting when spears become thin (pencil-thickness). This signals the crown needs rest.
- Let remaining spears grow into ferns. These feed the roots for next year.
Stop harvesting by mid-June in most of Pennsylvania. Allowing ferns to grow through summer ensures a good crop next spring.
Common Problems And Solutions
Asparagus is relatively pest-free, but a few issues occur in Pennsylvania.
Asparagus Beetles
These small beetles chew on spears and ferns. Hand-pick them in small gardens. For larger infestations, use insecticidal soap or neem oil.
Clean up plant debris in fall to reduce overwintering sites. Rotate where you plant if possible.
Frost Damage
A late spring frost can damage emerging spears. Cover young spears with row cover or old sheets if frost is forecast. Damaged spears will be mushy and discolored. Cut them off and new ones will grow.
Weed Competition
Perennial weeds like bindweed and Canada thistle are hard to control. Use thick mulch and hand-pull regularly. Avoid tilling near asparagus roots.
Poor Spear Production
If spears are thin or sparse, the bed may be too crowded. Divide crowns every 5–7 years. Also check soil fertility and pH.
Fall Care For Asparagus Beds
Fall preparation ensures a strong start next spring. Do not cut down ferns until they turn brown. The ferns send energy to the roots.
Cutting Back Ferns
Wait until after the first hard frost. Ferns will turn yellow or brown. Cut them at ground level and remove them from the bed. This prevents disease and pest overwintering.
Do not compost the fern debris if it had disease. Discard it in the trash.
Winter Mulching
Apply 4–6 inches of straw or shredded leaves after the ground freezes. This insulates the crowns from freeze-thaw cycles. Remove the mulch in early spring before spears emerge.
In milder parts of Pennsylvania, you may not need heavy mulch. But it helps in northern counties.
Varieties Best Suited For Pennsylvania
Choose varieties bred for cold climates. All-male hybrids produce more spears and live longer.
- Jersey Knight: High yielding, disease resistant. Good for all Pennsylvania zones.
- Jersey Giant: Early season, thick spears. Tolerates cooler soils.
- Mary Washington: Heirloom variety, reliable but lower yielding. Good for home gardens.
- Purple Passion: Sweet, purple spears. Less productive than green types but unique.
Buy crowns from northern nurseries. Southern-grown varieties may not adapt to Pennsylvania winters.
Frequently Asked Questions
Can I Plant Asparagus In Fall In Pennsylvania?
Fall planting is risky in Pennsylvania. Crowns may heave out of the ground during freeze-thaw cycles. Spring planting is more reliable.
How Deep Should I Plant Asparagus Crowns?
Plant crowns 6–8 inches deep in the trench. Cover with 2 inches of soil initially, then fill the trench gradually as spears grow.
How Long Does Asparagus Take To Grow From Crowns?
You can harvest lightly in the second year. Full harvests begin in the third year after planting. Patience pays off.
What Is The Best Soil For Asparagus In Pennsylvania?
Well-drained sandy loam with pH 6.5–7.5. Heavy clay soils need amending with compost or planting in raised beds.
Should I Soak Asparagus Crowns Before Planting?
Yes, soak crowns in water for 1–2 hours before planting. This rehydrates the roots and improves establishment.
Final Tips For Success
Planting asparagus at the right time is only the first step. Prepare the bed thoroughly and be patient. A well-established bed produces for 15–20 years with minimal care.
Mark your calendar for mid-April. Check soil temperature with a thermometer. If it reads 50°F at 4 inches deep, you are ready to plant. If not, wait a week and check again.
Pennsylvania’s climate is ideal for asparagus if you time it right. The cool springs and moderate summers allow slow, steady growth. Your reward will be fresh, tender spears every spring for years to come.
Remember to water deeply, mulch heavily, and never harvest the first year. These simple rules ensure a productive bed that outlasts many other garden crops. With proper timing and care, your Pennsylvania asparagus patch will become a family tradition.