Kalettes (Kale Sprouts / Flower Sprouts)

Think of Kalettes as the trendy, successful fusion of two vegetable heavyweights: Brussels sprouts and Kale.

They are not a product of genetic engineering, but rather the result of traditional cross-breeding (non-GMO) by a seed breeder working to create a vegetable that was versatile, easy to cook, and lacked the divisive pungency of a traditional sprout.

Appearance and Flavour

Kalettes look like tiny, palm-sized open cabbages with fringed, curly leaves. They typically feature a beautiful contrast of deep forest green and vibrant violet or purple hues. They hit the sweet spot between their two parent plants — delivering the nutty, earthy undertones of a Brussels sprout combined with the milder, sweeter notes of kale.

Because the rosettes are open and frilly rather than tightly packed, they have a much lighter, crunchier texture than a standard sprout. Importantly, their flavour becomes noticeably sweeter after exposure to frost, as cold temperatures convert starches to sugars.

Cooking Versatility

Kalettes are exceptionally easy to prepare — no scoring, no peeling. Simply rinse and cook. Their thin, open leaves cook rapidly:

• Sauté in olive oil and garlic for 3–5 minutes
• Roast until edges crisp like chips
• Grill on skewers for a smoky, charred flavour
• Eat raw in slaws or salads

Nutritional Value

Like all cruciferous vegetables, Kalettes are rich in Vitamins C and K and packed with antioxidants, making them a nutritious as well as flavourful addition to the garden and the plate.

How To Grow

How to Grow Kalettes

Kalettes are a rewarding but patient gardener's crop. As a long-season brassica, they typically take 5–7 months from sowing to harvest, producing their best flavour during the cooler autumn and winter months.

Timing

Kalettes thrive in cool weather and are best started in spring for a late autumn and winter harvest.

• Sow seeds indoors in early to mid-spring, around 6–8 weeks before the last expected frost.
• Transplant outdoors once seedlings are 10–15 cm tall and night temperatures remain reliably above freezing.
• Like Brussels sprouts, Kalettes taste significantly sweeter after being exposed to light frosts, which convert their starches into sugars.

Soil and Site

• Sunlight: Full sun — at least 6–8 hours of direct light per day.
• Soil: Firm, fertile, and well-drained. Incorporate well-rotted compost or manure before planting.
• pH: Slightly alkaline soil is preferred. Aim for a pH of 6.5–7.5. If your soil is acidic, apply garden lime several weeks before planting to raise the pH and help suppress clubroot disease.

Planting and Spacing

Kalettes grow into tall, sturdy plants that can reach 90 cm or more in height.

• Space plants 60 cm apart in rows 75 cm apart to ensure good airflow and reduce disease pressure.
• Firm the soil well around transplant roots — Kalettes, like Brussels sprouts, perform better in firm rather than loose soil.
• Staking: In exposed or windy areas, stake the main stem to prevent plants from toppling as they become top-heavy.

Watering and Feeding

• Keep soil consistently moist throughout the growing season. Irregular watering leads to bitter or tough rosettes.
• Apply a nitrogen-rich fertiliser every few weeks during the main growing period to support leafy growth.
• Mulch around the base of plants to conserve moisture and keep roots cool.

Pest Management

Kalettes share the same pest pressures as other brassicas:

• Cabbage white butterfly larvae: Use fine insect-proof netting or apply Bacillus thuringiensis (Bt) biological spray.
• Cabbage root fly: Place brassica collars flat on the soil around each plant's base at transplanting.
• Aphids: Check undersides of the frilly leaves regularly. A strong jet of water or insecticidal soap spray is effective.
• Birds: Net plants in areas where pigeons are a problem, particularly during winter.

Crop Rotation

Always rotate brassica crops, including Kalettes, on a minimum 3–4 year cycle to reduce the build-up of clubroot and other soil-borne diseases.

Harvesting

Harvesting Kalettes

Unlike a head of broccoli or cabbage that is harvested all at once, Kalettes provide a staggered, progressive harvest that can continue for several weeks or months — one of their most appealing qualities for home gardeners.

When to Harvest

Kalettes grow in the leaf axils — the joints where the large fan leaves meet the central stalk. They are ready to pick when the rosettes are approximately 2.5–5 cm (1–2 inches) in diameter and look like miniature, open-leafed, frilly cabbages. If the buttons are tight and smooth, they are not yet ready.

The Frost Factor: For the best flavour, wait until the plant has experienced one or two light frosts. This triggers the conversion of starches to sugars, producing noticeably sweeter rosettes. Plants left in the ground through cold spells continue to produce and improve in flavour.

Harvest from the Bottom Upwards

Rosettes at the base of the stalk mature first. Always begin picking from the bottom and work your way upward as the season progresses. Harvesting lower rosettes signals the plant to direct its energy toward the smaller, developing buttons higher up the stalk, extending the overall harvest period.

Technique

• Snap: Grasp the rosette firmly and snap it downward. It should detach cleanly from the stalk.
• Cut: If stems are thick or woody, use a sharp pair of snips or a small knife for a clean cut that avoids damaging the main stem.
• Leaf removal: As you harvest upwards, you can remove the large lower fan leaves to improve access. These leaves are also edible, though somewhat tougher than the rosettes themselves.

Storage

• Refrigerator: Store unwashed Kalettes in a perforated bag in the vegetable crisper. They remain fresh for approximately 7–10 days.
• In the ground: Plants are frost-hardy and can be left in the garden through winter, harvested fresh as needed — acting as natural cold storage.
• Do not wash until immediately before use, as moisture trapped in the frilly leaves accelerates deterioration.

After the Harvest

Once all rosettes have been picked, the plant is finished for the season. Remove stalks, chop them, and add to the compost heap — ensuring no pest-infested material is included.

Common Problems

Common Problems with Kalettes

Cabbage White Butterfly / Caterpillars

One of the most damaging pests for all brassicas, including Kalettes. Adult butterflies lay eggs on the undersides of leaves, and the emerging caterpillars can rapidly skeletonise foliage and destroy developing rosettes. Cover plants with fine insect-proof netting as a preventative measure. Inspect leaves regularly and remove egg clusters and caterpillars by hand. Bacillus thuringiensis (Bt) spray is an effective biological control.

Aphids

Both black bean aphid and cabbage aphid cluster on the undersides of leaves and around growing tips, weakening plants and potentially spreading viral diseases. A strong blast of water can dislodge colonies. Encourage natural predators such as ladybirds and lacewings, or use an insecticidal soap spray for heavier infestations.

Clubroot (Plasmodiophora brassicae)

A serious soil-borne disease that causes swollen, distorted roots and stunted growth. There is no cure once plants are infected. Prevent by maintaining soil pH above 7.0 (lime the soil if needed), practising a strict crop rotation of at least 4 years, and avoiding introducing infected soil or plants to the plot.

Cabbage Root Fly

The larvae tunnel into roots, causing wilting and poor growth. Place brassica collars (discs of cardboard or carpet underlay) flat on the soil around each transplant stem to prevent adult flies from laying eggs at the base of the plant.

Pigeons and Other Birds

Birds can devastate brassica foliage, especially in winter when other food is scarce. Physical exclusion with netting is the most reliable solution.

Downy Mildew

Yellow patches on upper leaf surfaces with grey-white mould beneath can appear in cool, damp, poorly ventilated conditions. Improve airflow by spacing plants correctly and removing badly affected leaves. Avoid overhead watering.

Nutrient Deficiency

As heavy feeders, Kalettes grown in poor or depleted soil may show yellowing leaves (nitrogen deficiency) or purple-tinged foliage (phosphorus deficiency, often in cold soils). Incorporate well-rotted compost or manure before planting and feed with a balanced or nitrogen-rich fertiliser during the growing season.