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Purple Top Turnip Bean · Zones 4–10
Growing Details
Zone-by-Zone Planting Calendar
| Zone | Indoor Start | Transplant | Direct Sow | Harvest |
|---|---|---|---|---|
| Zone 4 | — | — | May – June | August – September |
| Zone 5 | — | — | May – July | July – September |
| Zone 6 | — | — | May – July | July – October |
| Zone 7 | — | — | April – August | June – October |
| Zone 8 | — | — | April – August | June – November |
| Zone 9 | — | — | March – September | May – November |
| Zone 10 | — | — | February – September | May – December |
Complete Growing Guide
Begin site preparation in early spring by selecting your sunniest garden spot with protection from strong winds that can damage climbing vines. Purple Top Turnip Beans demand rich, well-draining soil with a pH between 6.0-7.0. Work in 3-4 inches of compost or aged manure to a depth of 12 inches, as these vigorous climbers are heavy feeders throughout their long growing season.
Direct sow seeds 2-3 weeks after your last frost date when soil temperatures consistently reach 60°F. Plant seeds 1-2 inches deep and 4-6 inches apart along the base of your support structure. Install 8-10 foot tall trellises, teepees, or strong poles before planting—these beans can easily reach 8 feet and will need sturdy support from the start. Avoid starting indoors as beans transplant poorly due to sensitive root systems.
Fertilize lightly at planting with a balanced 10-10-10 fertilizer, then switch to a low-nitrogen, phosphorus-rich fertilizer once flowering begins to encourage pod production rather than excessive foliage. Side-dress with compost monthly throughout the growing season.
Train young vines to their supports by gently wrapping tendrils around poles or trellis wires. The purple-tinged foliage will naturally climb counterclockwise. Mulch heavily around the base to retain moisture and suppress weeds, keeping mulch 3 inches from stems to prevent pest issues.
Common mistakes include planting too early in cold soil (which causes poor germination), inadequate support structures that collapse under the weight of mature vines, and overhead watering that promotes fungal diseases. Water at soil level consistently, providing 1-2 inches weekly.
Maximize yields by harvesting pods regularly when young and tender—daily picking during peak season encourages continued production. In zones 3-5, start seeds indoors 3-4 weeks before last frost if your season is shorter than 85 days, but handle transplants with extreme care.
Harvesting
Harvest Purple Top Turnip Beans when pods reach 4-6 inches long and display their characteristic purple streaking, typically 65-75 days from sowing. The pods should feel firm but yield slightly to gentle pressure—avoid pods that feel hard or show visible bean bulges, as these will be tough and stringy. Test readiness by snapping a pod; it should break cleanly with an audible snap and show no fibrous strings.
Harvest in early morning when pods are crisp and full of moisture. Use both hands when picking: hold the vine with one hand while gently pulling pods with the other to avoid damaging the plant. Purple pods will be most tender when the purple coloration is vibrant—faded purple indicates overmaturity.
Pick every 2-3 days during peak season to maintain continuous production. Young pods at 3-4 inches are excellent for fresh eating, while 5-6 inch pods are perfect for cooking applications. The purple coloration will fade to green during cooking, which is completely normal and indicates proper variety characteristics.
Storage & Preservation
Fresh Purple Top Turnip Bean pods maintain peak quality for 5-7 days when stored unwashed in perforated plastic bags in the refrigerator crisper drawer at 32-40°F. Their purple coloration may fade slightly during storage, but flavor remains excellent.
For freezing, blanch whole pods in boiling water for 3 minutes, then immediately plunge into ice water. Drain thoroughly and freeze in airtight containers for up to 8 months. The purple coloration will largely disappear during blanching, resulting in green beans.
Drying works exceptionally well for Purple Top Turnip Beans—allow pods to mature fully on the vine until papery, then harvest and shell out the dried beans for winter storage. These dried beans can be stored in airtight containers for 2-3 years and make excellent soup beans with their rich, meaty flavor. Pressure canning fresh pods follows standard bean processing times of 20 minutes for pints, 25 minutes for quarts at 10 pounds pressure.
History & Origin
Purple Top Turnip Bean represents a classic American heirloom variety that likely originated in the mid-1800s, during the peak period of American bean breeding and selection by small-scale farmers. The distinctive purple pod coloration comes from anthocyanin pigments, which were particularly prized by 19th-century gardeners who valued vegetables that served dual ornamental and culinary purposes.
This variety belongs to the broader family of "purple pod" beans that were commonly grown throughout the Midwest and Northeast, where their vigorous climbing habit made them ideal for small homestead gardens with limited space. The name "Turnip Bean" likely refers to the pod's plump, rounded shape when young, resembling small turnips.
Many purple-podded varieties were nearly lost during the 20th century as commercial agriculture focused on uniform green varieties, but dedicated seed savers and heirloom enthusiasts preserved Purple Top Turnip Bean through careful selection and sharing. Today, it's experiencing renewed popularity among gardeners seeking both productive harvests and ornamental value in their vegetable gardens, representing the practical beauty that defined traditional American garden varieties.
Advantages
- +Exceptional ornamental value with purple-streaked pods and purple-tinged foliage creating visual interest
- +Vigorous climbing habit maximizes production in minimal ground space
- +Outstanding flavor with rich, meaty texture superior to many modern varieties
- +Excellent dual-purpose variety for both fresh eating and dried bean production
- +Strong heirloom genetics provide good adaptability to various growing conditions
- +Continuous harvest period of 4-6 weeks with proper picking
- +Natural conversation starter and heritage variety for seed saving
Considerations
- -Requires substantial support structures due to vigorous 8-foot climbing habit
- -Purple coloration fades to green during cooking, disappointing some gardeners
- -Moderate disease resistance typical of heirlooms makes them more susceptible than modern hybrids
- -Cannot be successfully transplanted, limiting season extension options
- -Takes longer to mature than bush bean varieties at 65-75 days
Companion Plants
Plant Together
Marigold
Repels bean beetles, aphids, and nematodes while attracting beneficial insects
Carrots
Help loosen soil for bean roots and don't compete for nutrients
Corn
Provides natural support structure for climbing beans and benefits from nitrogen fixation
Squash
Ground cover reduces weeds and retains soil moisture, part of Three Sisters companion planting
Nasturtium
Acts as trap crop for aphids and cucumber beetles while repelling bean beetles
Radishes
Break up compacted soil and mature quickly without competing for space
Lettuce
Benefits from bean nitrogen fixation and provides ground cover to retain moisture
Summer Savory
Repels bean beetles and may improve bean flavor and growth
Keep Apart
Onions
Can inhibit bean growth and nitrogen fixation through root secretions
Garlic
Releases compounds that can stunt bean growth and interfere with beneficial bacteria
Fennel
Produces allelopathic compounds that inhibit growth of beans and most garden plants
Sunflowers
Compete heavily for nutrients and water, and may release growth-inhibiting chemicals
Pests & Disease Resistance
Resistance
Moderate disease resistance typical of heirloom varieties
Common Pests
Bean beetles, aphids, leafhoppers, spider mites
Diseases
Bacterial blight, rust, anthracnose, mosaic virus