SproutSmart
SproutSmart Intelligent Garden Sowing

Purple Plum

Radish
Botanical illustration of Purple Plum
🌱 28d to harvest Taproot

Sweetly peppery and vividly crisp, Purple Plum radish brings a jewel-toned crunch to the garden—its skin is a deep plum-purple th…

Planting Schedule

Add Purple Plum to your garden to build a schedule and get reminders.

Crop Dates

MilestoneDate
Start IndoorsDirect Sow
Last FrostMay 8th
Transplant / Sow OutdoorsMay 8th
Harvest BeginsJun 5th
Harvest EndsSep 30th

Crop Details

TraitValue
Days to Maturity28
Sun RequirementsFull SunFull sun
Growth HabitTaproot
Support NeededNone
Planting DepthNormal
Germination Temp (°F)55
Min Soil Temp (°F)45
Min Night Temp (°F)28
Harden Off (days)Not Required

Frequently Asked Questions


How do I manage common pests or diseases on Raphanus sativus (purple plum radish) in my garden?
Watch for flea beetles, which can leave small shot-holes in radish leaves and reduce root growth—use floating row cover from sowing until harvest and handpick heavily damaged plants. If you see pale, stippled leaves or silvery scarring, target thrips with insecticidal soap, applied in the cool morning, and remove badly infested leaves. For disease, avoid wet foliage and rotate beds, since overcrowded, damp conditions increase the risk of downy mildew and other leaf spotting that can affect yield.
How often should I water purple plum radish during the main growing phase?
Water so the soil stays evenly moist to a depth of about 6 inches, especially from germination through root bulking (roughly the first 2–4 weeks). In most home gardens this means about 1 inch per week total, split into 1–2 waterings, but adjust to weather so the top inch of soil never dries out completely. If the soil swings between dry and soggy, radishes are more likely to become pithy or overly hot.
How can I tell when purple plum radish (Raphanus sativus) is ready to harvest?
Harvest when the roots have filled out—typically about 28 days after sowing—and when the shoulder of the radish is clearly visible above the soil. For best eating, pull radishes as soon as they reach a thumbnail-to-dime sized diameter, because they become woody and can turn strong-flavored if left in the ground. If you want a milder radish, start checking from day 25 and harvest the earliest ones first.
Botanical illustration of Purple Plum

Sweetly peppery and vividly crisp, Purple Plum radish brings a jewel-toned crunch to the garden—its skin is a deep plum-purple that fades to a clean, tender white at the tip. At just 28 days, roots stay pleasantly slender and snappy, delivering a fresh, juicy bite that shines in salad mixes and bright garnishes. Grow a small stand for quick harvests and enjoy the striking color that makes every platter look freshly picked.

Sowing Tips

Transplant Conditions

Wait until soil reaches 45°F and nights stay above 28°F before moving outdoors.

Expert Note

For best crunch and mild flavor, keep soil evenly moist and sow in cool weather (radishes get hot-and-spicy fast).