Grow kohlrabi in plastic drawers 50 day

Why This Method Works

There's something incredibly satisfying about watching a plant mature from seed in an unexpected spot. For apartment dwellers, maximizing every inch of available growing space is key, and that's precisely why I've become such a proponent of growing kohlrabi in plastic drawers. This method isn't just a quirky novelty; it’s a highly efficient system that leverages container gardening principles perfectly suited for limited urban environments.

Kohlrabi, often overlooked in the urban garden, is a fantastic candidate for this approach. Its compact growth habit means you don't need sprawling beds or deep containers. The "bulb" (which is actually a swollen stem) develops above ground, making it less demanding on soil depth than root vegetables. Plastic drawers, repurposed from an old storage unit or picked up affordably, offer a surprising amount of surface area for their footprint. Their relatively shallow depth, typically 4-6 inches, is often ample for kohlrabi, which only needs about 6-8 inches of soil depth for optimal bulb development. Plus, their portability is a huge bonus. I can easily slide them around my balcony to chase the sun or move them indoors if an unexpected cold snap hits.

The beauty of this 50-day timeline isn’t just a catchy title; it's a realistic expectation for many kohlrabi varieties. There are fast-maturing types bred specifically for quick harvests. By choosing these varieties and providing consistent care, you can go from seed to harvest in less than two months. This rapid turnaround allows for multiple successions throughout the growing season, transforming a small space into a continuous production line.

What You'll Need

Getting started is straightforward, but selecting the right materials makes all the difference.

• Container: Plastic Drawer. I typically use standard plastic storage drawers, often found at discount stores or even salvaged from old furniture. Look for ones that are at least 12 inches wide and 18 inches long, with a depth of 5-7 inches. Crucially, you'll need to drill drainage holes – 8-10 holes of about 1/4 inch diameter is usually sufficient, spaced evenly across the bottom. Don't skip this, or you'll drown your plants.
• Growing System: Container Gardening. We’re effectively creating a mini raised bed. This means we'll be relying on a high-quality potting mix designed for containers, not dense garden soil.
• Kohlrabi Seeds: Opt for "early" or "fast-maturing" varieties. 'Early White Vienna', 'Purple Vienna', or 'Superschmelz' (though 'Superschmelz' might push the 50-day window slightly longer for a larger bulb) are excellent choices. Fresh seeds are vital for good germination rates.
• Potting Mix: A good quality, loose, well-draining potting mix is non-negotiable. I usually amend mine with about 10-15% perlite for extra drainage and aeration. This lightweight mix is perfect for containers. You'll need enough to fill your drawers to about an inch below the rim. If you're wondering exactly how much, check out our soil volume calculator for precise measurements based on your drawer dimensions.
• Fertilizer: A balanced, slow-release granular fertilizer, or a liquid fertilizer (half-strength, applied regularly) is ideal. Kohlrabi is a fairly heavy feeder.
• Watering Can: With a fine rose attachment to avoid displacing seeds.
• Small trowel or dibber: For planting.
• Measuring Tape/Ruler: For proper spacing.
• Optional: Shade cloth (for intense summer sun), pest netting (if pests are an issue), plant markers.

Step-by-Step Guide

This timeline is based on providing ideal conditions. Adjust for your specific climate and plant variety.

Days 1-3: Setup and Sowing

1. Prepare the Drawers: If you haven't already, drill your drainage holes. I place a layer of landscape fabric or old newspaper at the bottom of the drawer to prevent soil from washing out, but allow water to drain.
2. Fill with Potting Mix: Fill your drawers to about 1 inch below the rim with your prepared potting mix. Gently moisten the soil until it’s evenly damp, but not soggy.
3. Sow the Seeds: Kohlrabi needs about 4-6 inches between plants for the bulbs to develop properly. I usually sow seeds about 1 inch apart and plan to thin them later. Plant seeds about 1/2 inch deep. For a quick succession, you could plant two rows down the length of the drawer. Cover lightly with soil and gently water again.
4. Placement: Place the drawers in a location where they will receive at least 6 hours of direct sunlight. South-facing balconies are usually perfect.

Days 4-7: Initial Growth and Germination

• Watch for Sprouts: Kohlrabi typically germinates within 4-7 days if conditions are right (soil temperature around 65-75°F/18-24°C). Keep the soil consistently moist but never waterlogged. A fine misting bottle can be useful here.

• Light is Key: Once sprouted, ensure they get plenty of light to prevent leggy growth. If natural light is insufficient, a small LED grow light can make a huge difference.

Days 8-14: Thinning and First Feed

• Thinning: Once your seedlings have developed their first set of true leaves (the second set of leaves to appear), it's time to thin them. Carefully snip off the weaker seedlings at soil level, leaving the strongest plants spaced 4-6 inches apart. This is crucial for bulb development. Don't pull them, as this can disturb the roots of neighboring plants.

• First Feed: If using a granular slow-release fertilizer, I usually mix it into the top inch or two of soil during this phase according to package directions. If using liquid, start with a half-strength application every 7-10 days.

Days 15-30: Rapid Growth

• Consistent Watering: Kohlrabi needs consistent moisture, especially as the bulb begins to swell. Uneven watering can lead to splitting or tough, woody bulbs. I check the soil moisture daily by sticking my finger an inch or two into the soil; if it feels dry, I water.

• Pest Watch: Keep an eye out for common brassica pests like cabbage worms, aphids, or flea beetles. Early detection is key. Hand-picking or a gentle insecticidal soap spray usually handles small infestations. Consider using lightweight row covers (netting) if pests are a persistent problem.

• Fertilize: Continue with your chosen fertilization schedule. Healthy, dark green leaves are a good sign of adequate nutrition.

Days 31-50: Bulb Swelling and Harvest

• Continued Care: Maintain consistent watering and feeding. The kohlrabi bulbs (swollen stems) should be noticeably expanding above the soil line.

• Harvest Time: Kohlrabi is typically ready for harvest when the bulbs are 2-3 inches in diameter, similar to a tennis ball. Don't wait too long, as larger bulbs can become woody and lose flavor. To harvest, use a sharp knife to cut the bulb at the soil line, or gently twist and pull. You can even harvest some of the tender young leaves to add to salads!

• Troubleshooting:

  • Bulbs not forming: This is often due to insufficient light, overcrowding (didn't thin enough), or inconsistent watering. Ensure all these factors are optimized for your next batch.
  • Leggy seedlings: Lack of light. Move them to a brighter spot or supplement with a grow light.
  • Yellowing leaves: Could be a sign of nutrient deficiency (especially nitrogen) or overwatering. Check soil moisture and feeding schedule.

Common Mistakes to Avoid

1. Skipping Drainage Holes: This is probably the number one killer of container plants. Without proper drainage, roots sit in water, leading to root rot and quickly killing your kohlrabi. Always ensure your drawers have ample drainage.

2. Overcrowding: It’s tempting to leave all those promising seedlings, but kohlrabi needs space for its bulb to swell. If plants are too close, they compete for nutrients and light, resulting in stunted, tiny bulbs or none at all. Be ruthless with thinning!

3. Inconsistent Watering: Kohlrabi thrives on consistent moisture. Allowing the soil to completely dry out between waterings, or conversely, keeping it constantly waterlogged, will stress the plant. This leads to tough, woody bulbs, splitting, or bolting (going to seed prematurely).

4. Planting in Dense Garden Soil: While convenient, heavy garden soil compacts readily in containers, stifling root growth and preventing proper drainage. Always use a light, fluffy potting mix specifically formulated for containers.

Pro Tips for Maximum Success

1. Succession Planting: Maximize your harvest by planting new batches of kohlrabi seeds every 2-3 weeks in separate drawers. This ensures a continuous supply rather than one large harvest. Given the 50-day turnaround, you can have a fresh drawer ready every few weeks!

2. Fertilize Foliar Style: In addition to soil feeding, I occasionally use a diluted liquid fertilizer (like fish emulsion or a balanced organic blend) as a foliar spray early in the morning or late evening. This can give a quick nutrient boost, especially during rapid growth phases. Just be sure to rinse off any residue before harvest.

3. Monitor Soil Temperature: While ambient air temperature is important, soil temperature also plays a critical role in germination and growth. If your drawers are on concrete or a dark surface, they can heat up quickly, especially in direct sun. In cooler weather, dark colored drawers can absorb more heat, giving your plants a boost. Consider elevating drawers on wooden blocks to improve air circulation and prevent overheating in hot climates.

4. Rotate Your Drawers: If one side of your drawer is getting more sun, or if plants are shading each other, rotate the drawer 180 degrees every few days. This promotes even growth and ensures all plants get their fair share of light, leading to more uniform bulb development.

Growing kohlrabi in plastic drawers is a rewarding experience, transforming overlooked spaces into productive gardens. It's a testament to how adaptable urban gardening can be. Don't be afraid to experiment, observe your plants closely, and learn from each cycle. You'll be amazed at the fresh, homegrown bounty you can produce in just 50 days. If you need a hand with planning your layout or figuring out just how much soil to buy, remember to check out our free calculators at MicroGardenHacks for help with measurements.