When to Plant Asparagus in Wisconsin?
The optimal time to plant asparagus in Wisconsin is typically in early spring, as soon as the ground thaws and is workable, generally around late April or early May. Ensuring the soil is well-drained is critical for success.
Asparagus: A Wisconsin Gardener’s Delight
Asparagus is a perennial vegetable, meaning it will return year after year, providing delicious and nutritious spears for a decade or more. This makes planting it a worthwhile investment for any Wisconsin gardener. However, successful asparagus cultivation requires careful planning and timing, especially considering Wisconsin’s variable climate. Planting at the right time gives your asparagus the best possible start, setting it up for years of productive growth.
Benefits of Growing Asparagus
Beyond the delicious flavor, growing asparagus offers numerous advantages:
- Perennial Crop: Plant once and harvest for many years.
- Nutrient-Rich: Asparagus is low in calories and a good source of vitamins, minerals, and antioxidants.
- Early Spring Harvest: Provides fresh vegetables when other crops are still weeks away.
- Aesthetically Pleasing: Adds beauty to your garden with its feathery foliage.
- Sustainable: Requires minimal care once established.
The Asparagus Planting Process in Wisconsin
Planting asparagus involves several key steps:
- Soil Preparation: Asparagus requires well-drained soil. Amend heavy clay soil with compost, sand, and well-rotted manure. Aim for a soil pH between 6.5 and 7.5.
- Choosing Crowns: Purchase one-year-old asparagus crowns from a reputable nursery. Select varieties suited to Wisconsin’s climate, such as ‘Jersey Knight’, ‘Mary Washington’, or ‘Millennium’.
- Digging Trenches: Dig trenches 6-8 inches deep and 12-18 inches wide. Space trenches 4-5 feet apart.
- Planting Crowns: Place the crowns in the trenches, spacing them 12-18 inches apart. Spread the roots out carefully.
- Covering Crowns: Cover the crowns with 2-3 inches of soil. As the spears emerge, gradually fill in the trench with soil over several weeks.
- Watering and Mulching: Water thoroughly after planting. Apply a layer of mulch, such as straw or wood chips, to retain moisture and suppress weeds.
- Patience: Do not harvest spears in the first year or two. This allows the plants to establish a strong root system.
Timing is Everything: Why Spring Planting Works Best
Spring planting aligns with the asparagus plant’s natural growth cycle. By planting in late April or early May, you allow the crowns to establish roots before the heat of summer arrives. The warmth of the spring soil encourages root development, giving the plants a strong foundation for future growth. Planting too early risks frost damage, while planting too late can stress the crowns during the hottest part of the summer.
Common Mistakes to Avoid
- Poor Soil Drainage: This is the number one killer of asparagus. Ensure your soil drains well before planting.
- Planting Too Deep or Too Shallow: Planting at the correct depth (as described above) is crucial.
- Insufficient Watering: Asparagus needs consistent moisture, especially during the first year.
- Harvesting Too Early: Patience is key! Resist the urge to harvest spears in the first year or two.
- Ignoring Weed Control: Weeds compete with asparagus for nutrients and water. Keep your asparagus bed weed-free.
Choosing the Right Asparagus Variety for Wisconsin
Consider varieties known for their cold hardiness and disease resistance. Some popular choices include:
| Variety | Characteristics |
|---|---|
| Jersey Knight | All-male hybrid, high yielding, resistant to rust. |
| Mary Washington | Classic heirloom variety, reliable, good flavor, but susceptible to rust. |
| Millennium | All-male hybrid, excellent yield, good rust resistance. |
| Purple Passion | Unique purple spears, sweeter flavor, more tender than green varieties. |
Frequently Asked Questions About Asparagus Planting in Wisconsin
What happens if I plant asparagus too early in Wisconsin?
Planting asparagus too early, before the last expected frost, can damage the crowns. Frost can kill newly emerging spears and weaken the overall plant, delaying its growth and reducing future yields. It’s always best to err on the side of caution and wait until the danger of frost has passed.
Can I plant asparagus in the fall in Wisconsin?
While fall planting is possible in some regions, it’s generally not recommended in Wisconsin. The plants may not have enough time to establish a strong root system before winter sets in, increasing the risk of winterkill. Spring planting is almost always the better option.
How do I prepare the soil for asparagus planting?
Asparagus needs well-drained, fertile soil with a pH between 6.5 and 7.5. Amend heavy clay soils with plenty of compost, sand, and well-rotted manure to improve drainage. A soil test will help you determine the pH and nutrient levels. Add lime to raise the pH or sulfur to lower it, if needed.
How long does it take for asparagus to produce spears after planting?
It typically takes 2-3 years for asparagus to produce a significant harvest. Resist the temptation to harvest in the first year or two to allow the plants to establish a strong root system. In the third year, you can begin harvesting spears for a short period, usually 4-6 weeks.
What are the best companion plants for asparagus?
Several plants can benefit asparagus, and vice versa. Good companions include tomatoes, parsley, basil, and marigolds. These plants can help deter pests or improve soil conditions. Avoid planting asparagus near alliums like onions and garlic, as they can inhibit its growth.
How do I know when asparagus is ready to harvest?
Asparagus spears are ready to harvest when they are about 6-8 inches tall and the tips are still tightly closed. Use a sharp knife to cut the spears at or just below ground level. Avoid cutting too deep, as this can damage the crown.
How often should I water asparagus after planting?
Water asparagus thoroughly after planting and keep the soil consistently moist, especially during the first year. Water deeply but infrequently, allowing the soil to dry slightly between waterings. Established asparagus is more drought-tolerant but still benefits from regular watering during dry periods.
What kind of fertilizer should I use for asparagus?
Asparagus benefits from regular fertilization. Apply a balanced fertilizer, such as 10-10-10, in early spring before the spears emerge. You can also side-dress with compost or well-rotted manure during the growing season.
How do I control weeds in my asparagus bed?
Weeds can compete with asparagus for nutrients and water. Keep your asparagus bed weed-free by hand-pulling weeds regularly. Apply a layer of mulch, such as straw or wood chips, to suppress weed growth. Avoid using herbicides unless absolutely necessary, and always follow the label instructions carefully.
What are some common pests and diseases that affect asparagus?
Asparagus beetles are a common pest that can damage spears and foliage. Control them by hand-picking, using insecticidal soap, or introducing beneficial insects. Asparagus rust is a fungal disease that can cause orange pustules on the foliage. Choose rust-resistant varieties and ensure good air circulation to prevent rust.
How long will my asparagus plants last?
With proper care, asparagus plants can last for 15-20 years or even longer. Regular fertilization, weed control, and disease prevention will help extend the lifespan of your asparagus bed.
Can I grow asparagus in raised beds in Wisconsin?
Yes, asparagus can thrive in raised beds, especially in areas with poor soil drainage. Raised beds provide better drainage and allow you to control the soil composition. Follow the same planting guidelines as for in-ground planting, ensuring the raised bed is deep enough to accommodate the asparagus roots.