Illinois gardeners can safely transplant jicama seedlings outdoors after the danger of frost has passed, usually around mid-May. The best time to plant jicama in illinois is typically from late May to early June, when soil temperatures reach at least 60°F.
Jicama is a warm-season root vegetable that needs a long, hot growing season. In Illinois, you have a narrow window to get it right. This guide covers everything you need to know for a successful harvest.
Best Time To Plant Jicama In Illinois
Jicama is not a crop you can just toss in the ground whenever you feel like it. It requires careful timing because it is extremely frost-sensitive. Even a light frost will kill the plants instantly.
In Illinois, the last frost date varies by region. Northern Illinois (like Chicago) usually sees its last frost around mid-May. Southern Illinois (like Cairo) can be frost-free by late April. Central Illinois falls somewhere in between.
Here is a simple rule: wait until all danger of frost has passed AND the soil has warmed to at least 60°F. For most of Illinois, this means planting between May 20 and June 10.
Why Timing Matters So Much
Jicama needs about 150 to 200 frost-free days to mature fully. Illinois has a shorter growing season than jicama’s native tropics. If you plant too late, the roots won’t have time to swell before the first fall frost.
If you plant too early, cold soil will stunt growth or kill seedlings. Jicama seeds rot quickly in cool, wet soil. So timing is everything.
Regional Planting Dates For Illinois
Here are approximate planting windows for different parts of Illinois:
- Northern Illinois: June 1 to June 15
- Central Illinois: May 25 to June 10
- Southern Illinois: May 15 to June 1
These dates assume you are transplanting seedlings started indoors. Direct sowing is riskier and should be done 2 weeks later.
Starting Jicama Seeds Indoors
Because Illinois has a short growing season, you should start jicama seeds indoors. This gives your plants a head start of 6 to 8 weeks.
When To Start Seeds Indoors
Count backward from your outdoor planting date. If you plan to transplant on June 1, start seeds indoors around April 1 to April 15.
Use seed-starting mix in small pots or cell trays. Plant seeds 1/2 inch deep. Keep the soil warm, around 75°F to 85°F. Jicama seeds germinate best with bottom heat.
Seeds usually sprout in 7 to 14 days. Once they have two true leaves, give them plenty of light. A sunny window or grow lights work well.
Hardening Off Seedlings
Before transplanting outdoors, harden off your seedlings. This means gradually exposing them to outdoor conditions over 7 to 10 days.
- Start by placing them outside in a shady spot for 2 hours
- Increase time by 1 hour each day
- After 3 days, move them to partial sun
- By day 7, they can handle full sun all day
- Bring them indoors if frost is forecast
Hardening off reduces transplant shock. Skip this step and your plants may wilt or die.
Preparing The Soil For Jicama
Jicama grows best in loose, well-drained soil with a pH between 6.0 and 7.0. Heavy clay soil is a problem because jicama roots need room to expand.
Soil Preparation Steps
Follow these steps to get your soil ready:
- Test your soil pH. Add lime if it is below 6.0
- Loosen soil to a depth of 12 inches
- Remove rocks and debris that could deform roots
- Mix in 2 to 3 inches of compost or aged manure
- Add a balanced fertilizer like 10-10-10 at planting time
Jicama is a heavy feeder. It needs plenty of potassium for root development. Consider adding wood ash or kelp meal for extra potassium.
Raised Beds Are A Good Option
If your soil is heavy clay, use raised beds. They warm up faster in spring and drain better. This helps you plant earlier and avoid root rot.
Raised beds also make it easier to control soil quality. Fill them with a mix of garden soil, compost, and sand.
Transplanting Jicama Outdoors
When the time is right, transplant your seedlings carefully. Jicama has delicate roots that do not like disturbance.
How To Transplant
- Water seedlings well a few hours before transplanting
- Dig holes 12 inches apart in rows 24 inches apart
- Remove seedlings from pots gently, keeping root ball intact
- Place them at the same depth they were growing indoors
- Fill in soil and press lightly around the stem
- Water thoroughly after planting
Watering right after transplanting settles the soil and removes air pockets. Keep the soil consistently moist for the first week.
Using Row Covers
In Illinois, late spring can still have cool nights. Use row covers or cloches to protect young plants. This also speeds up growth by trapping heat.
Remove row covers once temperatures stay above 70°F during the day. Jicama loves heat, so do not shade it.
Caring For Jicama Plants
Jicama is not difficult to grow once established. It needs consistent care through the summer.
Watering
Jicama needs about 1 to 2 inches of water per week. Keep the soil evenly moist but not waterlogged. Mulch around plants to retain moisture and suppress weeds.
Drip irrigation is ideal. It keeps water off the leaves, reducing disease risk. Water in the morning so foliage dries quickly.
Fertilizing
Feed jicama every 3 to 4 weeks during the growing season. Use a fertilizer low in nitrogen but high in potassium. Too much nitrogen encourages leafy growth at the expense of roots.
A good option is a 5-10-10 formula. Apply according to package directions. Stop fertilizing once the roots start swelling in late summer.
Supporting Vines
Jicama is a climbing vine that can reach 10 feet or more. Provide a trellis, fence, or stakes for support. This keeps vines off the ground and improves air circulation.
You can also let them sprawl, but trellising saves space and makes harvesting easier. The vines do not need pruning.
Pest And Disease Management
Jicama has few pests in Illinois. Watch for aphids, spider mites, and flea beetles. Use insecticidal soap or neem oil if infestations occur.
Root rot can happen in poorly drained soil. Avoid overwatering and plant in raised beds if drainage is a concern. Powdery mildew may appear in humid weather; improve airflow by spacing plants properly.
Harvesting Jicama In Illinois
Jicama is ready to harvest when the roots are 4 to 6 inches in diameter. This usually takes 150 to 200 days from planting. In Illinois, harvest typically happens in late September to October.
When To Harvest
Watch for these signs:
- Leaves start to yellow and die back
- Roots push up slightly from the soil
- Skin feels firm and smooth
You must harvest before the first hard frost. Jicama roots cannot survive freezing temperatures. If frost is forecast, dig them up immediately, even if they are small.
How To Harvest
- Use a garden fork to loosen soil around the plant
- Pull the root gently by the stem base
- Brush off excess soil, do not wash
- Cut off the vines, leaving 1 inch of stem
Handle roots carefully. Bruised jicama spoils faster. Store unwashed roots in a cool, dark place like a root cellar or refrigerator.
Storing Jicama
Jicama stores well for several weeks under the right conditions. Keep it in a plastic bag in the refrigerator crisper drawer. It stays fresh for 2 to 3 weeks.
For longer storage, keep roots in a cool (50°F to 55°F), humid place. Do not let them freeze. Jicama can also be peeled, cut into sticks, and frozen for later use.
Common Problems And Solutions
Even with good timing, you may face challenges. Here are common issues Illinois gardeners encounter:
Small Roots
If your jicama roots are tiny at harvest, the growing season was too short. Next year, start seeds earlier indoors or use a fast-maturing variety. Some varieties mature in 120 days.
Split Roots
Split or cracked roots happen from uneven watering. Keep soil moisture consistent. Mulch helps prevent rapid drying and wetting cycles.
Bitter Taste
Jicama can taste bitter if stressed by heat or drought. Water regularly and provide afternoon shade in extreme heat. Harvesting at the right size also improves flavor.
Varieties Of Jicama For Illinois
Not all jicama varieties are equal. Some mature faster and suit shorter seasons better.
- San Juan: A popular variety that matures in 150 days. Good for most of Illinois.
- La Bonita: Matures in 120 to 140 days. Ideal for northern Illinois.
- Cristal: A crisp, sweet variety that takes 160 days. Best for southern Illinois.
Choose a variety that matches your region’s frost-free period. Check seed catalogs for maturity dates before buying.
Frequently Asked Questions
Can I plant jicama seeds directly in the ground in Illinois?
Direct sowing is risky because jicama needs warm soil and a long season. Start seeds indoors for best results. If you direct sow, wait until soil is 70°F and plant 2 weeks after your last frost date.
What is the latest I can plant jicama in Illinois?
The latest safe planting date is around June 15 for northern Illinois, June 20 for central, and June 30 for southern. Planting later than this risks an incomplete harvest before fall frost.
Does jicama need full sun?
Yes, jicama needs at least 8 hours of direct sunlight daily. Less sun results in smaller roots and weaker vines. Choose the sunniest spot in your garden.
How do I know when jicama is ready to harvest?
Harvest when roots are 4 to 6 inches in diameter and leaves begin to yellow. The skin should feel firm. Taste test one root to check for sweetness and crunch.
Can I grow jicama in containers?
Yes, but use a large container at least 18 inches deep and wide. Fill with loose, well-draining potting mix. Provide a trellis for the vines. Container plants may need more frequent watering and fertilizing.
Final Tips For Illinois Jicama Growers
Growing jicama in Illinois takes planning, but it is rewarding. The key is nailing the planting window. Start seeds indoors early, wait for warm soil, and protect plants from frost.
Keep an eye on the weather. If an early frost threatens, cover plants or harvest early. Even small jicama roots are edible and tasty.
Jicama is a conversation starter in the garden. Most people have never seen it grow. Share your harvest with neighbors and enjoy the crisp, sweet flavor in salads, stir-fries, or as a snack.
With the right timing and care, you can enjoy homegrown jicama from your Illinois garden. Start planning now for a successful season.