Growing Kohlrabi: Tips for a Healthy, Productive Harvest

Choosing Kohlrabi Varieties Wisely

I remember my first time growing kohlrabi. I chose a random variety without much thought, resulting in slightly undersized bulbs despite my best efforts.

Careful selection pays off immensely. For stellar yields, aim for reliable varieties like 'Early White Vienna' or 'Purple Vienna'—both deliver uniform bulbs in roughly 55–60 days.

Timing and Soil Preparation Spell Success

Like most veggies, timing your planting makes or breaks your kohlrabi harvest. This curious brassica thrives in chilly weather between 40–75°F (5–24°C).

Over the years, I've found sowing seeds directly outside in early spring—2 weeks before your area's last frost date—is ideal. For fall harvests, mid-to-late summer planting (60–70 days before frost arrives) hits the sweet spot.

Rich, fluffy soil is everything. Work in ample compost beforehand, ideally achieving a slightly acidic to neutral soil (6.0–7.0 pH).

"Well-composted soil increases your kohlrabi's yield potential by over 25%."

Proper Spacing and Planting Techniques

Kohlrabi prefers breathing room—I've learned the hard way that crowding leads to disappointingly small bulbs. Space plants every 6–8 inches (15–20 cm) apart with at least 12–18 inches (30–45 cm) between rows.

Sow seeds about ¼ to ½ inch (0.6–1.3 cm) deep. After germination—usually a painless 7–10 days—thin carefully to avoid disturbing neighboring seedlings.

Watering Practices for Juicy Kohlrabi

Kohlrabi bulbs swell best when consistently hydrated. Aim to deliver at least 1 to 1½ inches (2.5–3.8 cm) of water per week, preferably early in the morning to limit evaporation.

Mulching around each plant with straw or shredded leaves keeps moisture steady and curbs weed growth. Personally, I'm partial to chopped straw—it breaks down neatly into the soil later in the season.

Feeding and Fertilizing for Optimal Growth

Though kohlrabi isn't overly demanding, regular feeding works wonders. Once seedlings have developed their first true leaves, fertilize using an organic balanced fertilizer—something like fish emulsion or seaweed extract works beautifully.

A light side-dressing of compost or aged manure halfway through the growing season provides a timely boost, pushing bulbs from "average" to "spectacular."

Troubleshooting Common Kohlrabi Problems

Every gardener encounters a few setbacks, and kohlrabi is no exception. Two pests consistently cause me mild annoyance: cabbage worms and aphids.

• Cabbage worms: Inspect regularly and handpick these munchers off your plants. Row covers installed at planting time significantly reduce infestations.
• Aphids: Spray plants with a gentle stream of water or use insecticidal soap solutions to knock aphids back before they establish colonies.

Harvest at Peak Perfection

Knowing the ideal harvest time is essential. Aim to harvest bulbs when they're about golf ball to tennis ball sized—typically between 2–3 inches (5–7.5 cm) across.

Waiting too long results in woody, fibrous bulbs—something I've sadly tasted once too often. Gather promptly, cut at soil level and savor the crisp, subtly sweet flavor right away—or refrigerate bulbs wrapped loosely in damp towels for weeks of storage.

"A timely-picked bulb means maximum tenderness and flavor—delay at your peril."

Growing kohlrabi asks little but gives generously. With good sun, healthy soil, steady moisture, and smart spacing, you'll harvest crisp, flavorful bulbs worth savoring. Careful timing—planting early in spring or late summer—ensures quick, steady maturity. Keep weeds and pests in check, and your kohlrabi rewards you handsomely. Remember, this humble vegetable offers flavor and abundance to anyone willing to give it proper care and attention.