How To Grow Collards In Canada | Complete Guide

Download | How to Grow Collards | Complete Growing Guide (PDF)

Collard greens are a productive, cold-tolerant leafy vegetable that deserves a place in more Canadian gardens. Closely related to cabbage and kale, collards produce large, nutritious leaves that can be harvested repeatedly throughout the growing season. Established plants tolerate light frost, and cooler autumn weather often improves their flavour.

Unlike heading cabbage, collards do not form a compact head. Instead, they produce broad leaves around a central stem, allowing gardeners to harvest the mature outer leaves while the plant continues growing. A single healthy plant can provide fresh greens for several months.

Collards are especially useful in Canadian gardens because they can be planted in spring for summer harvests or established during summer for a productive autumn crop. They also tolerate moderate summer warmth better than many other cool-season leafy vegetables, although consistent moisture is important.

This complete guide explains how to grow collard greens from seed in Canada, including regional planting dates, seed germination, transplanting, soil preparation, watering, fertilizing, pest management, harvesting, and storage.

Collards Growing Guide at a Glance

Feature	Growing Requirement
Botanical Name	Brassica oleracea Acephala Group
Plant Type	Cool-season biennial usually grown as an annual leafy vegetable
Sun Exposure	Full sun, ideally 6–8 hours daily; tolerates partial shade
Soil	Fertile, well-drained, moisture-retentive soil; pH approximately 6.0–7.0
Start Indoors	Approximately 4–6 weeks before transplanting outdoors
Direct Sow	Spring once soil is workable, or early to midsummer for autumn crops
Sowing Depth	0.5–1 cm (¼–½ inch)
Germination	Approximately 5–10 days; favourable soil temperatures around 18–24°C
Plant Spacing	45–60 cm (18–24 inches) for mature plants
Row Spacing	60–90 cm (24–36 inches)
Watering	Approximately 2.5–4 cm (1–1½ inches) weekly, including rainfall; adjust for conditions
Difficulty	Easy to moderate
Container Growing	Yes; use large containers approximately 30–40 cm deep and wide or larger

Best Collard Varieties for Canadian Gardens

Collard varieties differ in plant size, leaf texture, growth habit, and maturity. For Canadian gardeners, reliable leaf production, cold tolerance, and suitability for the available growing season are important considerations.

Vates Collards

Vates Collards are a traditional heirloom variety known for their broad, dark blue-green leaves, relatively compact growth habit, and good tolerance of cool weather.

Vates is particularly well suited to Canadian gardens because it can provide repeated harvests during summer and autumn. Its compact habit also makes it a practical choice for raised beds and large containers.

Expect approximately 60–75 days for a mature crop under favourable conditions, although younger leaves can be harvested earlier. Days to maturity depend on growing conditions and whether the supplier measures from sowing or transplanting.

Other Collard Varieties

Caribou Seed Company features Vates collards. Other varieties are included for comparison and may differ in availability.

When to Plant Collards in Canada

Collards are cool-season vegetables, but they are more tolerant of summer warmth than crops such as spinach. This makes them useful for both spring and autumn planting across much of Canada.

For the most tender leaves, aim to establish plants during mild weather and maintain steady growth throughout the season.

Spring Planting

Start collard seeds indoors approximately 4–6 weeks before your intended outdoor transplanting date.

Harden off seedlings before planting them outdoors, generally around the last spring frost or slightly earlier when conditions are suitable. Established collards tolerate light frost, but newly transplanted seedlings should be protected from severe cold, strong winds, and repeated freezing.

Gardeners can also direct sow collard seeds in spring once the soil is workable and warm enough for reliable germination.

In Southern Ontario, indoor seed starting commonly begins in March or April, with transplanting during April or May depending on local weather. Colder regions may need to wait until May or early June.

Summer Planting for Autumn Harvests

Collards are particularly valuable as an autumn crop because cooler weather often improves their flavour. Plants established during summer can continue producing leaves after many warm-season vegetables have finished.

For a fall crop, sow approximately 10–14 weeks before your average first autumn frost, depending on the variety and whether you are direct sowing or transplanting.

Although collards tolerate frost, their growth slows as temperatures and daylight decrease. Give plants enough time to establish substantial foliage before late autumn.

When sowing during hot summer weather, keep the seedbed consistently moist and protect young seedlings from excessive heat until they become established.

Canadian Collards Planting Calendar

These planting windows are approximate. Always adjust for your local frost dates, the variety's maturity period, and current weather conditions. In short-season regions, starting transplants indoors can provide several additional weeks of growth.

Read More | Cold-Hardy Crops to Grow Late Into the Season

How to Direct Sow Collard Seeds

Direct sowing works well for collards, particularly when the soil has warmed sufficiently in spring or when planting a summer crop for autumn harvesting.

Step-by-Step Direct Sowing

1. Choose a Location: Select a sunny garden bed with fertile, well-drained soil.
2. Prepare the Soil: Loosen the top 20–25 cm and incorporate finished compost where needed.
3. Sow Seeds: Plant seeds approximately 0.5–1 cm deep, spacing them 5–8 cm apart initially.
4. Space Rows: Allow approximately 60–90 cm between rows.
5. Water Gently: Keep the seedbed consistently moist until seedlings emerge.
6. Thin Seedlings: Once true leaves develop, gradually thin to approximately 45–60 cm between mature plants.
7. Protect Young Plants: Use fine insect netting where flea beetles and cabbage butterflies are common.

Collards eventually become substantial plants. Crowding reduces airflow, increases competition for nutrients and water, and can make harvesting more difficult.

If seedlings are growing very close together, snip unwanted seedlings at soil level rather than pulling them out and disturbing nearby roots.

Read More | Vegetable Garden Spacing Guide: How Far Apart to Plant Vegetables

Collard Seed Germination

Collard seeds generally germinate within approximately 5–10 days under favourable conditions. Soil temperatures around 18–24°C encourage rapid and uniform germination, although seeds can germinate in cooler soil.

Tips for Successful Germination

• Use fresh, properly stored seeds.
• Sow approximately 0.5–1 cm deep.
• Keep the soil evenly moist without waterlogging.
• Avoid allowing the soil surface to form a hard crust.
• Protect emerging seedlings from flea beetles.
• Provide bright light once seedlings emerge.

Why Aren't My Collard Seeds Germinating?

Poor germination can result from dry soil, planting too deeply, waterlogged conditions, old seeds, or unsuitable temperatures.

Cold spring soil may delay emergence, while hot summer soil can dry quickly and reduce germination success. Check soil moisture and planting depth before reseeding.

Starting Collards Indoors

Starting collards indoors allows Canadian gardeners to establish healthy transplants before outdoor conditions become suitable. This is especially useful in regions with short growing seasons.

Step-by-Step Indoor Sowing

1. Start seeds approximately 4–6 weeks before your intended transplanting date.
2. Fill seed trays or individual cells with clean seed-starting mix.
3. Sow seeds approximately 0.5–1 cm deep.
4. Maintain temperatures around 18–24°C during germination.
5. Keep the growing medium evenly moist.
6. After germination, provide approximately 14–16 hours of suitable grow-light exposure daily.
7. Thin to one healthy seedling per cell.
8. Transplant when seedlings have approximately 3–4 true leaves and a well-developed root system.

Follow your grow-light manufacturer's recommended hanging distance. The correct distance depends on the fixture's brightness and design.

Avoid leaving seedlings in small containers for too long. Rootbound or overcrowded seedlings may establish slowly after transplanting.

Read More | Seed Starting 101: Beginner Guide for Canadian Gardeners

Hardening Off and Transplanting Collards

Indoor-grown collard seedlings must gradually adjust to outdoor sunlight, wind, and fluctuating temperatures before transplanting.

Harden off seedlings over approximately 7–10 days. Begin with short periods outdoors in a sheltered, shaded location, then gradually increase their exposure to sunlight and outdoor conditions.

How to Transplant Collards

1. Choose a cool, cloudy day or transplant in the late afternoon.
2. Water seedlings before removing them from their containers.
3. Prepare planting holes approximately 45–60 cm apart.
4. Carefully remove each seedling while keeping the root ball intact.
5. Plant at approximately the same depth as in the seed tray. Slightly leggy seedlings may be planted a little deeper, keeping the growing point above soil level.
6. Firm the soil gently and water thoroughly.
7. Protect young transplants from severe cold, strong winds, and insect pests.

Collards tolerate cool weather, but newly transplanted seedlings can still experience stress from sudden temperature changes. Use lightweight row covers when needed, ensuring they do not trap excessive heat on warm days.

Soil, Sunlight, and Fertilizing Requirements

Collards grow best in fertile, well-drained soil that retains moisture without becoming waterlogged. A soil pH of approximately 6.0–7.0 is suitable for healthy growth.

Sunlight

Provide full sun, ideally 6–8 hours daily. Collards tolerate partial shade, although plants may grow more slowly and produce smaller leaves.

In regions with very hot summer afternoons, some light afternoon shade can help reduce moisture stress.

Preparing the Soil

Before planting, remove weeds and loosen compacted soil. Incorporate finished compost to improve soil structure, moisture retention, and nutrient availability.

Collards belong to the brassica family, so avoid repeatedly planting them in beds previously occupied by cabbage, broccoli, kale, cauliflower, or other brassicas. Crop rotation helps reduce the buildup of pests and soilborne diseases.

Read More | How to Prepare Garden Soil for Planting: A Canadian Spring Guide

Fertilizing Collards

Because collards are grown primarily for their leaves, they require adequate nitrogen to support steady foliage production.

Incorporate finished compost before planting. If soil fertility is insufficient, apply a balanced vegetable fertilizer according to soil test recommendations or product directions.

Plants harvested repeatedly over several months may benefit from additional feeding if growth slows or leaves become pale. However, avoid excessive nitrogen, which can encourage overly soft growth.

Yellowing leaves are not always caused by nutrient deficiency. Check soil moisture, drainage, and root health before applying fertilizer.

Watering and Mulching Collards

Consistent moisture encourages tender leaves, steady growth, and productive repeated harvests.

Provide approximately 2.5–4 cm of water weekly, including rainfall, as a starting point. Actual requirements depend on temperature, soil type, plant size, and rainfall.

Water deeply at the base of plants when possible. Avoid allowing the soil to dry excessively, particularly during hot summer weather.

Apply a layer of straw, shredded leaves, or other suitable organic mulch around established plants to conserve moisture, suppress weeds, and moderate soil temperatures. Keep mulch slightly away from the stems.

Caribou Growing Note: Harvest for Tender Leaves

For the best eating quality, harvest collard leaves while they are young to medium-sized. Large, mature leaves remain edible but often require longer cooking to become tender. Consistent watering helps maintain good leaf quality throughout the growing season.

Growing Collards in Raised Beds and Containers

Raised Beds

Collards grow well in raised beds when provided with fertile soil and adequate room for mature plants.

Provide at least 25–30 cm of workable soil depth and space plants approximately 45–60 cm apart for full-size growth.

Raised beds often warm earlier in spring, but they may also dry out more quickly during summer. Check soil moisture regularly.

Read More | Square Foot Gardening: Maximize Small Spaces

Containers

Collards can also be grown in large containers, making them suitable for patios, balconies, and smaller gardens.

Choose containers approximately 30–40 cm deep and wide or larger, with adequate drainage holes. Plant one mature collard plant per large container, or use a wider planter that allows the recommended spacing.

Use quality potting mix and monitor moisture carefully. Container-grown plants may need more frequent watering and occasional feeding because nutrients can be washed out during irrigation.

Common Collard Pests and Growing Problems

Collards share many pests and diseases with other brassica vegetables. Regular inspection and early prevention are particularly important because the leaves are the edible portion of the crop.

Common Pests

• Imported Cabbageworms: Green caterpillars chew irregular holes in leaves. Inspect plants regularly and use fine insect netting to prevent butterflies from laying eggs.
• Cabbage Loopers: Caterpillars feed on foliage and may cause significant leaf damage. Inspect the undersides of leaves and remove caterpillars when found.
• Flea Beetles: Small beetles create numerous tiny holes, particularly in young seedlings. Protect plants with fine insect netting immediately after sowing or transplanting.
• Aphids: These insects cluster on tender growth and leaf undersides. Monitor plants and manage infestations before populations become large.
• Slugs and Snails: Feed on leaves during cool, damp weather. Reduce damp hiding places and inspect plants regularly.
• Cabbage Root Maggots: Larvae feed on roots, causing stunting and wilting. Properly secured insect barriers can help prevent adult flies from laying eggs near plants.

Diseases and Growing Problems

• Clubroot: A soilborne disease that causes swollen roots, wilting, and stunted growth. Avoid moving contaminated soil, improve drainage, and rotate brassica crops. Where clubroot is present, appropriate soil pH management may reduce disease pressure but will not eliminate the pathogen.
• Black Rot: A bacterial disease that may produce yellow, V-shaped lesions along leaf margins and darkened veins. Use healthy seed, remove infected plant debris, and avoid handling wet foliage.
• Downy Mildew: Can develop during cool, humid conditions. Improve airflow and reduce prolonged leaf wetness.
• Yellowing Leaves: May result from natural ageing, nutrient deficiency, water stress, poor drainage, or disease.
• Slow Growth: May result from overcrowding, insufficient fertility, limited sunlight, root damage, or unsuitable temperatures.

Why Are My Collard Leaves Turning Yellow?

Older lower leaves naturally yellow as plants mature. However, widespread yellowing may indicate nutrient deficiency, inconsistent watering, poor drainage, root problems, or disease.

Check soil moisture, inspect for pests, and assess the plant's overall condition before applying fertilizer.

Remove badly damaged or diseased leaves and dispose of them appropriately rather than leaving infected material in the garden.

Read More | How to Grow Cabbage in Canada: Complete Growing Guide

When and How to Harvest Collards

Unlike heading cabbage, collards can be harvested repeatedly throughout the growing season. This makes them particularly productive in Canadian vegetable gardens.

Young leaves may be ready to harvest approximately 30–45 days after sowing under favourable conditions. Larger, mature leaves generally take longer, often around 60–75 days or more depending on the variety and growing conditions.

Signs Collards Are Ready to Harvest

• Leaves have reached a useful size for cooking or fresh eating.
• Leaves are firm, healthy, and well coloured.
• The plant has developed enough foliage to support continued growth.
• Outer leaves can be removed without damaging the central growing point.

How to Harvest Collards

1. Choose healthy, mature outer leaves near the base of the plant.
2. Use clean scissors or garden shears, or carefully snap leaves from the stem.
3. Remove only a few leaves from each plant at a time.
4. Leave the smaller central leaves and growing point intact.
5. Return regularly to harvest additional mature outer leaves.
6. Refrigerate harvested leaves promptly.

Can You Harvest Collards More Than Once?

Yes. Collards are excellent cut-and-come-again vegetables. As long as the central growing point remains intact and plants remain healthy, they continue producing new leaves.

Harvesting regularly also helps prevent leaves from becoming excessively large and tough.

Harvesting Collards After Frost

Established collard plants tolerate light frost, and cool autumn temperatures often improve leaf sweetness.

In many Canadian regions, collards can remain productive after the first light frosts. However, repeated hard freezes and prolonged severe cold may damage leaves and eventually kill plants.

For autumn harvesting, allow plants to establish before temperatures decline significantly. Lightweight row covers or low tunnels can help protect foliage during colder weather, although they will not guarantee winter survival in very cold regions.

Caribou Growing Note: Don't Remove the Growing Point

When harvesting collards, remove the larger outer leaves while leaving the central cluster intact. This allows the plant to continue producing fresh leaves for future harvests. Avoid stripping too many leaves at once, especially late in the season when regrowth is slower.

How to Store Collards

Fresh collards are best enjoyed soon after harvesting, but they can be refrigerated or frozen for later use.

Refrigerator Storage

1. Remove damaged or yellowing leaves.
2. Avoid washing until ready to use unless necessary.
3. Wrap leaves loosely in a slightly damp paper towel or place them in a perforated produce bag.
4. Store in the refrigerator's vegetable drawer.
5. Use within approximately 5–7 days for the best quality.

Freezing Collards

Collards freeze well and are particularly useful in cooked dishes during winter.

1. Wash leaves thoroughly and remove thick stems if desired.
2. Cut leaves into manageable pieces.
3. Blanch collard greens in boiling water for approximately three minutes.
4. Transfer immediately to ice water to stop cooking.
5. Drain thoroughly.
6. Pack into freezer-safe containers or bags and freeze promptly.

Frozen collards are ideal for soups, stews, sautés, and other cooked dishes.

How to Use Collards in the Kitchen

Collards are traditionally cooked by simmering, braising, steaming, or sautéing. Their sturdy leaves hold up well to longer cooking times, making them excellent for hearty meals.

Young, tender leaves can also be used in wraps or finely sliced into salads. For mature leaves, removing the thick central stem before cooking can improve tenderness.

Collards pair well with garlic, onions, beans, smoked seasonings, lemon, and other savoury ingredients.

Grow Collards from Seed Today

Collards are a reliable and productive addition to Canadian vegetable gardens, offering nutritious leafy harvests from spring through autumn.

For the best results, plant in fertile soil, provide generous spacing, maintain consistent moisture, and harvest mature outer leaves regularly while leaving the central growing point intact.

With their excellent cold tolerance and extended harvesting season, collards are a valuable choice for traditional vegetable gardens, raised beds, and larger containers.

Featured Collard Seeds

Collards 'Vates' Compact heirloom collards with dark green leaves and good cold tolerance. Suitable for traditional vegetable gardens, raised beds, containers, and repeated autumn harvesting. Shop Collard Seeds

Download | How to Grow Collards | Complete Growing Guide (PDF)

Frequently Asked Questions About Growing Collards

Are collards easy to grow in Canada?

Yes. Collards grow well in many Canadian regions and tolerate cool weather, making them suitable for spring, summer, and autumn harvesting.

When should I plant collards in Canada?

Start seeds indoors approximately 4–6 weeks before transplanting, or direct sow in spring once the soil is workable. For autumn crops, plant during early to midsummer according to your local growing season.

How long do collards take to grow?

Young leaves can often be harvested in approximately 30–45 days, while mature leaves generally take around 60–75 days or longer, depending on the variety and growing conditions.

How deep should I plant collard seeds?

Sow seeds approximately 0.5–1 cm (¼–½ inch) deep.

How long do collard seeds take to germinate?

Seeds generally germinate within approximately 5–10 days under favourable conditions.

Can I start collards indoors?

Yes. Start seeds approximately 4–6 weeks before transplanting and harden seedlings off before moving them outdoors.

How far apart should collard plants be?

Space mature plants approximately 45–60 cm apart, with 60–90 cm between rows.

Can collards grow in containers?

Yes. Use large containers approximately 30–40 cm deep and wide or larger, with good drainage.

Do collards tolerate frost?

Yes. Established plants tolerate light frost, and cool weather can improve leaf sweetness. Prolonged severe freezing may damage or kill plants.

Can I harvest collards more than once?

Yes. Harvest mature outer leaves while leaving the central growing point intact to encourage continued production.

Why are my collards bitter?

Collards naturally have a slightly earthy, sometimes bitter flavour. Heat, drought, and very mature leaves may intensify bitterness. Cooler weather often improves their sweetness.

Why are my collard leaves turning yellow?

Yellowing may result from normal leaf ageing, nutrient deficiency, water stress, poor drainage, or disease. Check the plant's overall condition before making changes.

Can collards grow in summer?

Yes. Collards tolerate moderate summer warmth better than some cool-season leafy vegetables, although they benefit from consistent moisture during hot weather.

What is the difference between collards and kale?

Both belong to the same species, but collards typically have broad, relatively smooth leaves, while many kale varieties have curled or deeply textured leaves.

How long do collards keep producing?

Healthy plants can produce leaves for several months when outer leaves are harvested regularly and the central growing point remains intact.

Can I freeze collards?

Yes. Blanch prepared leaves, cool immediately, drain thoroughly, and freeze in suitable containers.

Should I harvest collards before frost?

Not necessarily. Established plants tolerate light frost, and cooler temperatures can improve flavour. Harvest or protect plants before prolonged severe freezing.

See You in the Garden!