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Cauliflower is a little harder to grow than its cabbage and broccoli relatives. It can’t live in temperatures that are too cold or too hot, so this is the main reason. It’s not impossible, though. If you want to add a little challenge to your garden this year, why not try growing cauliflower from seeds? Read on for instructions on how to plant cauliflower seeds.
Cauliflower grows best at around 60 degrees F. (15 C. ). Too far below that and the plant will die. If you put it too high, the head will “button,” which means it will break into many small white pieces instead of the solid white head you want. Avoiding these extremes means growing cauliflower from seeds very early in the spring, then transplanting them outside. The best time for planting cauliflower seeds indoors is four to seven weeks before the last average frost. If you have short springs that get hot quickly, you should aim for closer to seven. Sow your seeds in fertile material at a depth of half an inch (1 cm. ) and water them thoroughly. Cover the soil with plastic wrap until the seeds have sprouted. Cauliflower seed germination usually takes eight to ten days. When the seedlings appear, remove the plastic and keep the soil evenly moist. Put grow lights or fluorescent lights right on top of the seedlings and set a timer for 14 to 16 hours a day. Keep the lights just a few inches (8 cm. ) above the plants to keep them from getting long and leggy.
Cauliflower is a cool-season crop that requires some babying to grow properly and produce good heads. Starting cauliflower seeds indoors allows you to control conditions and get a head start on the season. Proper timing is important for getting seedlings into the garden at just the right growth stage. Here’s when and how to start cauliflower seeds indoors for a bountiful harvest.
Why Start Cauliflower Seeds Indoors?
Growing cauliflower from seedlings started indoors has several advantages over direct seeding into the garden
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You can get plants growing 4-6 weeks before outdoor planting. This gives cauliflower a head start.
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Indoor conditions are ideal for germination. Seeds sprout quickly and uniformly indoors.
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Seedlings are protected from cold, pests, diseases and bad weather in their early stages
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You can grow from heirloom or specialty seeds not readily available as transplants.
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It costs much less than buying transplants from a nursery.
Starting seeds indoors does require diligent care. But with a little effort, you’ll gain hardier transplants that yield earlier crops.
When to Start Cauliflower Seeds Indoors
Timing is critical when starting cauliflower seeds indoors. Here are some general guidelines for when to sow seeds for spring and fall crops:
For Spring Harvest
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Start seeds indoors 4-6 weeks before your last average spring frost date.
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In warmer climates, start closer to 4 weeks before. In cooler areas go with 6 weeks.
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Transplant seedlings into the garden 2-4 weeks before the last frost.
For Fall Harvest
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Start seeds indoors 6-8 weeks before your first average fall frost date.
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Transplant seedlings 4-6 weeks before the first frost.
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For late fall harvest, sow seeds 8-10 weeks before frost and transplant 6-8 weeks before.
Check your local frost dates and adjust timing accordingly. Track weather forecasts daily as cold spells or heat waves may affect planting schedules. If very hot summer weather follows spring crops, choose bolt-resistant varieties.
How to Start Cauliflower Seeds Indoors
Follow these steps for the best results starting cauliflower seeds indoors:
Choose a Container
- Select containers at least 2-3 inches deep with drainage holes. Options include seed trays, peat pots or recycled containers.
Use a Seed Starting Mix
- Use a sterile, soilless mix to prevent damping off disease. Mixes for seed starting are lightweight and retain moisture.
Plant the Seeds
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Fill containers with moistened mix and sow seeds 1⁄4-1⁄2 inch deep. Space 1-2 inches apart.
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Cover trays with plastic wrap or dome lids to retain moisture until sprouting.
Provide Warmth
- Cauliflower seeds germinate best at 70°F. Use heating mats or grow lights to maintain ideal temperature.
Give Light as Soon as Sprouts Emerge
- Place under grow lights or in a sunny window. Keep lights 2-4 inches above seedlings.
Gradually Acclimate and Transplant
- Harden off seedlings by slowly increasing outdoor time over 7-14 days before transplanting.
With this simple process, you’ll get robust cauliflower seedlings ready to thrive once moved into the garden! Just be sure to time plantings properly based on intended harvest dates.
Tips for Growing Strong Seedlings
Here are some added tips for raising healthy cauliflower seedlings indoors:
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Water carefully to keep the soil consistently moist but not soggy.
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Turn pots or trays frequently so seedlings grow straight and evenly.
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Thin overcrowded seedlings to the strongest ones 1-2” apart when true leaves appear.
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Increase air circulation with small fans to prevent fungus and disease.
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Stop fertilizing 2 weeks before hardening off to avoid transplant shock.
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Let soil dry slightly between waterings as hardening off begins.
What to Grow
Recommended cauliflower varieties to start indoors include:
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Snow Crown – early maturing, cold hardy
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Amazing – self-blanching
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Purple Sicily – heat tolerant
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Graffiti – vivid purple heads
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Cheddar – bright orange heads
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Veronica – lime green Romanesco type
Try a few different types to see which grow best in your climate and conditions. Record timing and results each season to optimize future indoor seed starting.
When to Transplant Outdoors
Move hardened off cauliflower seedlings into the garden based on the size of plants and weather/soil temperature:
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Transplant in early spring once seedlings reach 4-6 inches and soil temps are at least 50°F.
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For fall crops, transplant once summer heat passes and soil temps drop back to 60-70°F.
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Delay transplanting if temperatures swing to extremes. Cauliflower needs consistent cool conditions.
How to Transplant Cauliflower Seedlings
Follow these tips when moving seedlings from indoors to the garden:
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Water seedlings well the day before transplanting.
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Prepare garden beds with compost and organic fertilizer. Cauliflower needs rich soil.
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Gently remove seedlings from containers, disturbing roots as little as possible.
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Plant at the same depth they were growing in containers. Firm soil around roots.
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Water immediately and shield new transplants from sun a few days until established.
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Watch weather forecasts and be ready to protect from cold or heat with covers.
With the right variety choice and optimal transplant timing, cauliflower seedlings started indoors will flourish in the garden. Just don’t rush the process – patience in the early stages pays off later!
Common Problems and Solutions
Here are some potential issues and how to address them when starting cauliflower seeds indoors:
Leggy seedlings – Insufficient light, move closer to lights
Damping off disease – Soil too wet, allow to dry between waterings
Slow growth – Too cold, increase temperature
Purple leaves – Phosphorus deficiency, amend soil
Root-bound plants – Transplant sooner before roots overtake containers
Flowering after transplanting – Exposure to cold or heat, protect with covers
Poor head formation – Irregular watering, maintain constant moisture
Wilting – Under or overwatering, check soil and adjust
Holes in leaves – Caterpillars, remove by hand or use Bt spray
With attentive care while starting cauliflower indoors, you’ll avoid most issues and have success right from the start. Adjust your methods each season until you find the optimal schedule and technique in your growing environment.
The Benefits of Starting Cauliflower Seeds Indoors
Growing cauliflower from transplants started inside offers many advantages:
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Extends the harvest season with earlier maturity
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Avoids transplant shock that direct sown seeds face
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Minimizes weed, disease and pest pressure indoors
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Conserves garden space during early spring
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Provides flexibility if weather turns cold or hot
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Allows monitoring and care of every individual
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Gives you control over varieties grown
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Requires minimal investment in supplies
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Saves money compared to purchasing nursery transplants
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Spreads out tasks over several weeks
If you’ve shied away from growing cauliflower in the past, starting seeds indoors makes the process much more manageable. Once moved to the garden at the right stage, transplants quickly establish and resume vigorous growth.
Enjoy Your Harvest
With the right variety choices suited to your growing season length and weather conditions, proper timing, gentle handling and protection from temperature extremes, the seedlings you start inside will reward you with robust cauliflower plants and bountiful harvests.
Cauliflower may seem challenging, but is well worth the effort. The taste and nutrition of homegrown cauliflower far outshine store-bought. Bring on those colorful heads by starting seeds indoors at just the right time.
Growing Cauliflower from Seeds
Transplant your seedlings outside two to four weeks before the last frost date. They’ll still be sensitive to cold, so make sure to harden them off carefully first. Set them outside, out of the wind, for about one hour, then bring them inside. Repeat this every day, leaving them outside an hour longer each time. If it’s unusually cold out, skip a day. Keep this up for two weeks before planting them in the ground.
The Complete Guide to Growing Cauliflower
FAQ
When should you start cauliflower seeds indoors?
How long does it take to grow cauliflower from seed to harvest?
How big should cauliflower seedlings be before transplanting?
Should I soak cauliflower seeds before planting?
Can you plant cauliflower seeds indoors?
Cauliflower seeds can be sown outdoors or started indoors. We recommend starting cauliflower seeds indoors to control temperature, humidity, and light. For spring planting, start cauliflower seeds indoors 4 to 6 weeks before the last frost date. For fall/winter growing, plant seeds 12 weeks before the first fall frost.
When can I plant cauliflower indoors?
If you’re planting in the spring, count back 4 to 6 weeks from your last frost date. This is when you can start seeds for cauliflower indoors under a grow light. For those of us in warmer climates, this could be as early as January.
When should I plant cauliflower seeds?
Cauliflower is a cool-season crop. Cauliflower thrives in temperatures between 57°F and 68°F (14°C-20°C). Set cauliflower seedlings in the garden about two or three weeks before the average last frost date, not earlier. Sow cauliflower seeds indoors 4 to 6 weeks before setting seedlings in the garden.
How do you plant cauliflower seeds?
Use a chopstick or pencil tip to press a little hole into the mix in each cell. Sow each cauliflower seed about 1/4″ deep and cover with seed starting mix or moist potting soil. Plant only one seed per cell to avoid the need to thin seedlings later. 3.