February is when spring planning becomes action. Start warm-season crops indoors, harden off any early transplants from January, and continue planting cool-season crops where conditions allow.

February tasks

Start warm-season seeds indoors

Count backward from your target transplant date (usually 1–2 weeks after your last spring frost date) and subtract the days to germination plus growth time:

  • Tomatoes, peppers, eggplant: Start 6–8 weeks before transplanting
  • Basil and other herbs: Start 4–6 weeks before transplanting
  • Squash, cucumbers, melons: Start 3–4 weeks before transplanting (they grow fast)

How to start seeds indoors:

  1. Use seed-starting mix (a light, sterile mix with peat moss or coco coir and perlite or vermiculite)
  2. Moisten the mix thoroughly before filling pots or trays
  3. Sow seeds at depth indicated on the packet (usually 1–2 times the seed diameter)
  4. Place under grow lights 2–3 inches above the seedlings, or on a sunny south-facing windowsill
  5. Keep soil moist but not waterlogged
  6. Maintain 65–75°F if possible
  7. Use a fan on low speed to simulate wind and strengthen stems

Seedlings need 12–16 hours of light per day. Rotate trays daily if using a windowsill so seedlings don't stretch toward one side.

Bottom heat speeds germination. A seedling heat mat under the tray, set to 70–75°F, cuts germination time noticeably for warm-season crops like peppers and eggplant, which can otherwise take two to three weeks in a cool room. Remove the mat once seedlings emerge — established seedlings don't need the extra warmth and grow stockier at slightly cooler room temperature. Peppers in particular are notorious for slow, uneven germination without bottom heat; some gardeners see germination drop from three weeks to one.

Running the fan matters more than it sounds. A small oscillating fan on low, running a few hours a day, does two things: it thickens stems through mechanical stress (the same response that makes outdoor-grown seedlings stockier than windowsill ones), and it keeps air moving across the soil surface, which is one of the more effective ways to prevent damping-off fungi from establishing in still, humid air near the surface.

Potting up as seedlings grow

Most seeds are started in small cells, which is deliberately space-efficient — but slow-growing, long-season crops like tomatoes and peppers often need to move to a larger pot before it's time to transplant outdoors. Signs it's time: roots visible circling the bottom of the cell, or growth that has visibly slowed compared to a week or two earlier.

  • Move up one size, not several: a seedling from a 2-inch cell goes to a 4-inch pot, not straight to a gallon container — too much soil volume around small roots holds excess moisture and invites rot
  • Bury tomato stems deeper when potting up; tomatoes root readily along a buried stem, and a deeper set produces a stronger root system by transplant time
  • Water thoroughly after potting up and keep out of direct strong light for a day while roots settle into the new soil

Continue hardening off early transplants

If you started cool-season crops in January, they are likely ready for the hardening-off process:

  1. Begin with 1 hour outdoors in a protected, shaded spot
  2. Increase exposure by 1–2 hours daily over 7–14 days
  3. Aim for 10–12 hours of outdoor time by day before transplanting
  4. Bring plants in if temperatures drop below frost tolerance for your crops
  5. Move transplants to a sheltered spot that receives morning sun and afternoon shade

Hardening off is not a quick process. Rushing leads to sunburned, wilted transplants that stall in the garden.

Begin spring cleanup

As soil becomes workable (when it crumbles rather than smears), begin clearing winter debris:

  • Remove dead leaves and plant material (except from diseased plants)
  • Rake back winter mulch from early beds
  • Clear gutters and drainage areas to prevent water pooling
  • Check for pests or disease on perennials and shrubs

Save cleaned leaves for compost or use as mulch in areas where disease was not present.

Monitor soil temperature

Check soil temperature in your beds daily or every few days. Even if air temperature is warm, soil in February is often still cold. Don't rush planting based on warm air — soil temperature is what matters.

Starting seeds indoors

Seed-starting mix recipe

Use a commercial seed-starting mix, or make your own:

  • 50% peat moss or coco coir
  • 50% perlite or vermiculite (or a 50/50 mix of each)

This creates a light, well-draining medium that prevents damping off (a fungal disease that kills seedlings at soil level).

Container options

  • Seed trays with peat pots: Easy to transplant (peat pots go directly in the ground), but peat dries quickly
  • Cellular trays with cell packs: Reusable, durable, good drainage
  • Toilet paper tubes or newspaper pots: Free option, works well
  • Yogurt cups with drainage holes: Free, larger volume for crops like squash

Regardless of container, ensure drainage holes are present.

Light requirements

  • Grow lights: Most reliable; place 2–3 inches above seedling tops, raising as plants grow
  • Sunny south-facing windowsill: Works for some crops, but seedlings will stretch toward light
  • Combination: Windowsill plus supplemental grow lights in morning and evening

Seedlings need 12–16 hours of light per day for sturdy growth. A basic shop-light fixture with full-spectrum LED or T5 fluorescent tubes is enough for home seed starting — the specialty "grow light" marketing on many higher-priced fixtures buys convenience (built-in timers, adjustable height) more than a meaningfully different light spectrum for seedling-stage growth. The distance matters far more than the exact bulb type: keep tubes 2–3 inches above the seedling tops and raise the fixture as they grow, since intensity falls off sharply with distance under most home fixtures. Put lights on a timer — 14–16 hours on is a reliable default, and a timer removes the daily habit of remembering to turn lights on and off.

Water management

Keep soil moist but never waterlogged. A spray bottle works for gentle watering for very small seedlings, but bottom-watering (setting the tray in an inch of water for 10–15 minutes, then removing it) works better for anything past the first true leaves — it draws water up to the roots without disturbing the soil surface or wetting the foliage, which reduces fungal disease risk. Water when the surface of the soil feels dry to the touch. Overwatering is a common cause of damping off, more common than underwatering at this stage; a seedling that looks droopy is more often oversaturated at the root than thirsty.

Temperature and humidity

Most seeds germinate best at 65–75°F. Once sprouted, they prefer slightly cooler temperatures (60–70°F) to grow stocky rather than stretching toward light. Humidity is helpful during germination but reduce it once seedlings emerge to prevent fungal disease — remove any humidity dome or plastic cover as soon as the first sprouts appear, not after the whole tray has germinated.

Fertilizing seedlings

Seed-starting mix typically has no nutrients of its own, so seedlings need feeding once they develop their first true leaves (the second set, after the initial rounded seed leaves). Use a balanced liquid fertilizer diluted to one-quarter the label strength — seedling roots are easily burned by fertilizer concentrations that mature plants tolerate without issue. Feed every 7–10 days at that dilution rather than a single stronger dose; consistent light feeding produces steadier growth than infrequent heavy feeding.

Troubleshooting seedling problems

Most seed-starting failures trace to a short list of causes. Matching the symptom to the cause saves a wasted second attempt.

  • Leggy, pale, stretched seedlings: insufficient light, most commonly from lights kept too far above the seedlings or from relying on a windowsill alone. Move lights within 2–3 inches of the tops and increase daily light duration.
  • Seedlings collapsing at the soil line (damping off): a fungal disease favored by cool, wet, still conditions. There is no cure once it starts — remove and discard affected seedlings immediately to protect the rest. Prevent it next time with sterile mix, bottom watering, good airflow from a fan, and avoiding overwatering.
  • No germination at all: check that soil temperature actually reached the seed's minimum (a cool room can sit well below the 65–75°F most seeds want even if it feels comfortable to a person), and check the seed's age and viability.
  • Uneven, patchy germination: usually old or marginal seed, or an uneven watering pattern that dried out part of the tray. A germination test (described in the January guide) diagnoses old seed before you rely on a full tray of it.
  • Yellowing lower leaves with otherwise normal growth: often a nitrogen deficiency once the seedling has used up the modest reserve in its seed leaves. Begin or increase dilute fertilizing.
  • Purple or reddish leaf undersides, especially on tomatoes and peppers: commonly a response to cold temperatures reducing phosphorus uptake rather than an actual phosphorus deficiency in the mix. Warming the growing area usually resolves it within days without any fertilizer change.
  • White, fuzzy mold on the soil surface (not on the seedling itself): saprophytic mold feeding on organic matter in the mix, usually harmless to the plant but a sign conditions are too damp and still. Increase airflow and let the surface dry slightly between waterings.

What to plant in February

In warm climates (USDA zones 8 and warmer): Continue planting cool-season crops. By late February, soil should be warm enough (50–60°F) to sow carrots, beets, and other root crops. Plant more lettuce, spinach, and leafy greens for succession harvests.

In moderate climates (zones 6–7): Check soil temperature. If it is at least 40–50°F, direct-seed cool-season crops: peas, fava beans, carrots, beets, and turnips. Transplant cool-season brassicas (broccoli, cabbage, cauliflower) if soil is workable and frost risk is manageable.

In cold climates (zones 5 and colder): Wait on outdoor planting. Focus on seed starting indoors. If using season extension (cold frames, row covers), you can plant some cool-season crops late in the month.

Cool-season crops to sow or transplant in February

  • Direct-seeded: peas, fava beans, carrots, beets, turnips, radishes, spinach, lettuce
  • Transplants: broccoli, cabbage, cauliflower, kale, other brassicas
  • Overwintered crops: Check on garlic and early alliums; they should be showing growth by late February

Indoor starts to begin in February

  • Tomatoes (for mid-April transplant in zone 7; adjust for your zone)
  • Peppers and eggplant
  • Basil
  • Marigolds and other warm-season annuals
  • Squash (late in the month to avoid root-bound transplants)
  • Onions and leeks from seed, in warm climates only (see below)

Starting onions and leeks from seed

Onions and leeks are unusual among warm-season starts: they benefit from an early, long indoor head start (10–12 weeks before transplant) because they grow slowly and bulb size at harvest correlates with total leaf growth achieved before the plant switches from vegetative growth to bulbing, which is triggered by day length. Sow thickly in flats rather than individual cells, and trim the tops back to about 3 inches with scissors every couple of weeks once they exceed that height — this is standard practice for onion seedlings and keeps them from flopping over and tangling. In climates with a very short frost-free season, onion sets (small dormant bulbs) or nursery transplants are a simpler alternative to starting from seed.

Chitting potatoes (mild and warm climates)

Where soil will be workable for potato planting by March, February is the time to "chit" (pre-sprout) seed potatoes: set them in a single layer, eyes up, in a cool, bright location (not direct sun) for 2–4 weeks before planting. This produces short, sturdy green sprouts rather than the long, pale, fragile sprouts potatoes develop in dark storage, and chitted potatoes typically emerge from the ground faster and more evenly than unsprouted ones.

Hardening off transplants

Hardening off is the process of acclimating indoor-grown seedlings to outdoor conditions. It is essential for success and cannot be rushed.

Why hardening off matters

Indoor seedlings have no wind, lower light intensity, consistent temperature, and high humidity. Outdoor conditions are harsh by comparison. Without hardening off, transplants:

  • Wilt severely when exposed to sun and wind
  • Experience growth check and may not recover for weeks
  • Are vulnerable to sunburning (bleached, papery leaves)
  • Often die outright

Hardening-off protocol

Week 1–2 before transplant date:

  1. Days 1–2: 1 hour outdoors in afternoon shade; bring inside
  2. Days 3–4: 2–3 hours outdoors in afternoon shade
  3. Days 5–6: 4–5 hours outdoors, morning sun and afternoon shade
  4. Days 7–8: 6–8 hours outdoors, morning sun and afternoon shade
  5. Days 9–10: 8–10 hours outdoors, morning sun and afternoon shade
  6. Days 11–12: 10–12 hours outdoors, including some direct morning sun
  7. Days 13–14: Full day and night outdoors (bring in only if frost threatens)

The location matters. Choose a spot that receives morning sun (gentle) but afternoon shade (protection). Wind protection (a fence or shrub) helps in the first few days.

Why hardening off works: the physiology

Hardening off isn't just habituation — it produces measurable physical changes in the plant. Gradual outdoor exposure thickens the leaf cuticle (the waxy outer layer that controls water loss), increases wax deposits on leaf surfaces, and stimulates the plant to develop a more branched, robust root system than it would indoors. Wind exposure specifically triggers a response called thigmomorphogenesis — mechanical stress from moving air signals the plant to invest in shorter, thicker, stronger stem tissue rather than tall, thin growth optimized for reaching light. This is also why a small fan indoors before transplanting helps: it's a low-dose version of the same wind-stress signal.

A cold frame is a practical middle step for hardening off: move flats into a cold frame with the lid propped open during the day and closed at night, gradually increasing the ventilation gap over a week or two. This automates much of the daily carrying-in-and-out that a full hardening-off schedule otherwise requires.

Common hardening-off mistakes

  • Rushing the process: Don't jump from indoors to full sun in one day
  • Forgetting about wind: Wind dries seedlings quickly; protect them
  • Inconsistent care: Bringing plants in and out erratically confuses them
  • Letting them dry out: Hardening-off seedlings still need consistent moisture; check soil moisture daily during the process, since outdoor exposure to sun and wind dries pots faster than the indoor environment they came from
  • Hardening off on an overcast forecast, then transplanting into sudden bright sun: match the hardening conditions as closely as possible to actual transplant-day conditions

Sources and further reading