Plant Profile & Key Characteristics
Overview: Lepidium sativum (garden cress) is a fast-growing annual leaf crop of about 40-60 cm, grown for its edible, peppery leaves and sprouts. It is a cool-season plant grown across USDA zones 2-10a in spring, or zones 10a-11 from autumn.
Quick Specifications
| Specification | Attribute |
|---|---|
| Plant Type / Life Cycle | Annual (herbaceous leaf crop) |
| Mature Size | 40-60 cm tall (16-24 in) |
| Growth Rate | Fast |
| Toxicity | Non-toxic / edible (salad crop) |
| Hardiness | USDA zones 2-10a (spring) or 10a-11 (autumn planting) |
Growth Form & Structure
- Height & Spread: Reaches about 40-60 cm (16-24 in) if left to bolt, but usually harvested young; sprouts can be grown indoors.
- Growth Habit & Form: Low leafy rosette when young, sending up flowering stems as it matures.
- Lifespan & Maturity: Very fast; leaves and sprouts are ready within days to a few weeks, completing its cycle in one season.
Anatomy & Physical Features
- Leaves & Foliage: Edible green leaves that are deeply and finely lobed (pinnatisect) with rounded tips, in a radial rosette; peppery in flavour.
- Flower Characteristics: Tiny white flowers with a pinkish tinge, borne in clusters.
Primary Uses & Landscape Value
- Edible Uses: Leaves and sprouts are eaten raw in salads, and the sprouts are also used in stir-fries; peppery flavour.
- Functional & Ornamental Roles: Fast salad and microgreen crop, easily grown indoors or in the garden.
Care Guide: Planting, Soil & Watering
Overview: Garden cress is a fast-growing leafy annual that does well in part to full shade and moist, slightly alkaline soil. It needs steady moisture and can also be grown indoors year-round for sprouts.
Quick Care Requirements
| Requirement | Ideal Condition |
|---|---|
| Planting Season | Spring in temperate climates; autumn to winter in frost-free areas |
| Growth Rate | Fast |
| Soil Type | Moist, fertile soil |
| Soil pH | Slightly alkaline |
| Water Need | Moderate to high; keep consistently moist |
Planting & Establishment
- Best Planting Season: Sow in spring in temperate climates or in autumn to winter in frost-free areas; for sprouts it can be grown indoors any time of year.
- How to Plant:
- Hole Preparation: Sow seed directly and shallowly.
- Soil Amendments: Use a fertile, moisture-retentive soil.
- Planting Depth: Sow the seed shallowly, barely covered.
- Growth Speed & Expectations: A very fast grower, ready to harvest quickly at about 40-60 cm (16-24 in).
Soil, Watering & Drainage Care
- Soil Mix & Drainage Needs: Keep the soil moisture-retentive and do not let it dry out, or the plants bolt.
- Watering Schedule & Technique:
- Young / Newly Planted: Keep the soil constantly moist for even germination.
- Established: Water frequently and lightly; never let it dry out.
- Seasonal Adjustments: Water more in heat and provide shade to keep it from bolting.
Climate, Light & Hardiness
Garden cress is a very fast, cool-season salad leaf for temperate, Mediterranean and subtropical gardens, and it is unusual among these crops in preferring half to full shade rather than full sun. It crops best in cool weather - heat sends it quickly to flower and toughens the leaves - and for sprouts it can be grown indoors year-round.
Quick Climate Specifications
| Climate Zones | Temperate, Mediterranean and subtropical (cool-season) |
| USDA Hardiness Zones | Approx. 2–11, grown seasonally |
| Optimal Temp Range | approximately 10–18 °C (50–64 °F) |
| Cold Damage Begins | light frost tolerated; first damage around −3 to −5 °C (27 to 23 °F) |
| Approx. Survival Minimum | hardened plants briefly near −6 to −8 °C (21 to 18 °F) |
| Frost Tolerance | Low to Moderate |
| Light Conditions | Half Shade / Full Shade |
| Wind Tolerance | Moderate |
Sunlight & Light Exposure
Optimal Light Setup
The facts give half to full shade as optimal - shade keeps the fast, tender leaves cool and mild and slows bolting.
Shade & Heat Management
Cress is a shade-friendly crop that stays productive in cooler, dimmer positions; keeping it out of hot direct sun is the main way to delay flowering in warm weather.
Best Exposure & Orientation
A cool, lightly shaded bed - or a bright indoor spot for sprouts - suits it best; reserve open sun for the coolest part of the year only.
Temperature Extremes & Hardiness
USDA Hardiness & Regional Limits
The site lists USDA 2–11 for this seasonal crop, autumn-to-winter sown in frost-free areas and spring-sown in temperate areas; sprouts can be raised indoors all year. The zone marks where the cool-season crop can be timed outdoors rather than a plant that overwinters everywhere.
Cold Damage & Winter Protection
Cress tolerates light frost, with first damage around −3 to −5 °C (27 to 23 °F) and hardened plants briefly to about −6 to −8 °C (21 to 18 °F); harder freezes cut it back. Tender seedlings and indoor-raised plants are the most cold-sensitive.
Frost Sensitivity
Light frost is tolerated but the soft, fast growth is not deeply frost-hardy; a sustained freeze ends the outdoor crop.
Extreme Heat Tolerance
Heat is the limit - warm weather triggers rapid bolting and coarse, hot-flavoured leaves, so it is grown in cool, shaded conditions and sustained temperatures much above approximately 22–24 °C (72–75 °F) are avoided.
Wind, Humidity & Microclimate
Humidity Preferences
The fast, soft leaves stay best in cool, evenly moist air; dry heat accelerates bolting and toughening.
Wind Tolerance
Low, soft plants (40–60 cm / 16–24 in at most) are wind-firm but their tender growth can desiccate in hot, drying wind.
Rainfall & Seasonal Moisture
Adapted to the cool, moist season; consistently moist conditions keep leaves tender, while hot, dry spells force flowering. This is a climate-adaptation note, separate from routine irrigation.
Microclimate Recommendations
A cool, shaded, evenly moist pocket - or an indoor windowsill for sprouts - gives the longest run of tender leaves.
Growing in Pots, Balconies & Indoors
Garden cress is the classic indoor crop – the grower rates it as a houseplant, and it germinates within days on a sunny windowsill for a quick cut of peppery leaves. Interestingly, he does not recommend it for ordinary outdoor planters; it is grown fast and fresh in shallow trays rather than kept as a long-term potted plant.
Quick Details
- Container Size: Shallow seed trays or pans – the grower does not recommend regular deep planters
- Indoor Suitability: A true indoor crop – the grower’s pick for a houseplant; fast and reliable on a bright sill
- Best Spot: part to full shade – it tolerates low indoor light; a bright kitchen sill out of harsh sun is ideal
- Soil & Drainage: Damp tissue, cotton wool, or a thin layer of fine seed mix kept constantly moist
- Watering in Pots: Keep the medium constantly moist – it is a sprint crop that must never dry out
Indoors & On the Windowsill
- A genuine houseplant: One of the few crops the grower marks yes for indoors – sow thickly on damp tissue, cotton wool or a thin layer of mix in a shallow tray and cut in about a week.
- Light: It copes with lower light than most (the grower lists part to full shade), so a bright sill without harsh, hot sun is ideal; too much heat makes it bolt and turn bitter.
- Succession: Resow every week or two for a constant supply; it is a fast, throwaway crop rather than a plant to keep.
On a Balcony or Patio
- Keep it simple: Since the grower does not recommend regular outdoor containers, treat balcony growing as short-lived trays in a cool, lightly shaded, sheltered spot rather than deep pots in full sun, which dry it out and turn it bitter.
- Shelter: Wind and reflected heat dry shallow trays in minutes, so keep them out of the worst exposure and check the moisture often.
Choosing the Pot, Soil & Long-Term Care
- Containers: Shallow trays or seed pans rather than deep pots – the aim is fast, shallow, moist growth, which is why the grower does not treat it as a planter crop.
- Medium: Damp tissue, cotton wool, or a thin layer of fine seed mix kept constantly moist; drainage is barely an issue over such a short life.
- Feeding: None needed – it is harvested long before it would use any feed.
- Between sowings: Simply start a fresh tray; there is no long-term plant to repot or overwinter.
Growing this plant in a greenhouse
A greenhouse can give cress plant frost protection, cold protection, a longer growing season and winter growing.
Greenhouse at a glance
| Greenhouse suitability | Good - clearly useful |
|---|---|
| Main benefits | frost protection, cold protection, a longer growing season, winter growing |
| Season extension | can grow through winter |
| Outdoor protection advisable below | about -5°C |
| Suitable types | unheated greenhouse, polycarbonate greenhouse |
| Heating | No added heat is normally needed. |
Related greenhouse guides
- Greenhouses: How to Choose the Right Greenhouse
- Polycarbonate Greenhouses: What to Look for Before Buying
- Greenhouse Propagation Equipment
Fertilizing & Feeding
A moderate feeder: fertile soil plus light, steady feeding through the cool growing season keeps leaves tender, while heavy nitrogen softens growth and invites pests.
Quick Fertilizing Specs
| Feeding Level | Moderate |
|---|---|
| Main Nutrient Priority | Nitrogen for continuous, tender leafy growth on a balanced base. |
| Best Feeding Period | During the cool-season active growing period (spring and autumn). |
| Organic Options | Compost or well-rotted manure worked in ahead of planting, plus diluted liquid feeds during growth. |
| Micronutrients | Usually supplied by fertile soil; iron or manganese chlorosis can show on new leaves in cold or high-pH soil. |
| Soil pH | Near neutral to slightly alkaline. |
| Reduce/Stop Feeding | Ease off if leaves grow soft and lush, and keep feeding light near harvest. |
Feeding by Growth Stage
Establishment after sowing or transplanting
Settle seedlings in and build a strong root system before rapid leaf growth begins.
| Nutrient direction | A balanced, complete fertilizer worked into fertile soil; lean mostly on well-prepared, organic-matter-rich soil at this stage. |
|---|---|
| Timing | From sowing or transplanting until seedlings are actively pushing out new leaves. |
| Frequency | Light feeding is usually enough while roots establish. |
| Fertilizer types | Balanced complete garden fertilizer, Compost or other organic matter worked into the bed |
| Precautions | Avoid heavy fertilizer against tender seedling roots, which can burn them; keep the bed evenly moist. |
Active leaf growth
Drive fast, tender leafy growth for harvest.
| Nutrient direction | A nitrogen-forward complete fertilizer to support continuous leaf production. |
|---|---|
| Timing | During the cool-season growing period once plants are established. |
| Frequency | Several light feedings spread across the active growing season. |
| Fertilizer types | Nitrogen-forward complete fertilizer, Diluted liquid feed or a light side-dressing |
| Precautions | Excess nitrogen leaves growth soft and more attractive to aphids and caterpillars; keep feeding steady rather than heavy. |
Repeated cut-and-come-again harvest
Keep fresh regrowth coming after each cutting of leaves.
| Nutrient direction | A balanced complete fertilizer with adequate nitrogen to push new leaves after each harvest. |
|---|---|
| Timing | Through the harvest window as leaves are cut and allowed to regrow. |
| Frequency | A light feeding after cuttings helps regrowth; feed sparingly. |
| Fertilizer types | Balanced complete fertilizer, Diluted liquid feed applied after cutting |
| Precautions | Avoid overfeeding leaves you will eat soon; keep the soil evenly moist to reduce bitterness and bolting. |
Nutrient Deficiency Signs & Corrections
Older, lower leaves turn pale then yellow while growth slows and leaves stay small.
| Possible causes | Low soil nitrogen or nitrogen leached out by heavy watering or rain, Cold or waterlogged soil limiting nutrient uptake, Poor, low-organic-matter soil |
|---|---|
| Appears first on | Older, lower leaves |
| What to check | Recent heavy rain or irrigation that may have leached nitrogen, Soil organic matter and general fertility, Soil temperature and drainage |
| Possible correction | Apply a nitrogen-forward complete fertilizer at label rates and keep the soil evenly moist; build organic matter over time. |
Yellowing and browning scorch along the margins of older leaves.
| Possible causes | Low soil potassium, Sandy soil that holds few nutrients, Drought stress limiting potassium uptake |
|---|---|
| Appears first on | Margins of older leaves |
| What to check | Soil test for potassium, Watering consistency, Soil type and organic matter |
| Possible correction | Use a complete fertilizer that includes potassium and keep watering consistent. |
New leaves yellow between the veins while the veins themselves stay green.
| Possible causes | High (alkaline) soil pH locking up iron and manganese, Cold, wet soil reducing micronutrient uptake, Waterlogging or poor root health |
|---|---|
| Appears first on | Youngest leaves |
| What to check | Soil pH, Drainage and root condition, Whether symptoms followed cold, wet spells |
| Possible correction | Correct soil pH toward the plant’s preferred range and, if needed, apply a chelated iron or manganese product per its label. |
Pruning, Training & Seasonal Maintenance
Garden cress (Lepidium sativum) is a very fast annual grown two ways — as a sprout/microgreen cut whole at the base within days, or grown on for its lobed leaves. Its note is explicit: ‘recommend to cut the blossom.’ Removing the flower stalk is the key maintenance act, because cress bolts quickly and flowering ends useful leaf production. As a sprout crop it can be grown indoors year-round and simply harvested by cutting at soil line.
Quick Pruning & Maintenance Specs
| Pruning Tolerance | High — regrows readily from the crown/nodes after leaf cutting |
| Primary ‘Pruning’ Action | Cut-and-come-again leaf harvest through the cool season |
| Secondary Action | Removing the bolting flower stalk once heat or long days trigger it |
| Typical Frequency | Outer leaves every 1–2 weeks; one whole-plant shear per flush |
| Main Objective | Keep leaves tender and mild, and delay bolting |
| Young Plant Priority | Thin to spacing and let the rosette establish before cutting |
| Mature Plant Priority | Harvest outer leaves; cut the flower stalk if bolting |
| Best Tool Type | Precision snips only |
| Sprout / Microgreen Harvest | Cut the whole seedling at soil line a few days after germination |
| Avoid Heavy Cutting During | Once it bolts — cut the blossom early to prolong leaf |
Pruning by Plant Age & Size
Newly Established (Seedling)
Thin—do not cut—seedlings to their final spacing, snipping surplus plants off at soil level rather than pulling so the roots of the keepers are not disturbed. A young cress plant should build a full rosette before you take any leaves.
Young / Formative
As a sprout crop there is no ‘young/mature’ distinction — you cut the entire stand at soil level while it is still a seedling. Grown on for leaves, let a small rosette form, then begin taking outer leaves once the plant has established.
Mature / Established
For leaf use, harvest outer leaves at the base after the plant establishes, and cut the flower stalk (‘the blossom’) promptly to keep it in leaf. Cress moves to flower fast, so a leaf crop has a short window — grow it in succession.
Seasonal Pruning Schedule
Cool-Season Growth
This is a cool-season crop; while it is bulking in mild weather it needs no cutting beyond ongoing harvest. Steady picking of the oldest outer leaves keeps the centre producing tender new ones.
Bolting (Heat & Lengthening Days)
Cress bolts readily; once the small pink-white flower clusters form, leaf quality falls off. Cutting the blossom early, as its own note advises, prolongs the leaf phase a little. Because it is so quick, the reliable approach is frequent small sowings rather than trying to hold one crop.
Ongoing Sanitary
Remove leaves badly chewed by Pieris (cabbage-white) caterpillars or disfigured by disease. Bin—do not compost—material with brassica downy mildew, white rust or clubroot.
Structural Pruning & Training
None. This is a low leafy rosette with no stem framework to shape — there is no leader, no branches and no training system. The only ‘renewal’ is shearing the whole plant back to a few centimetres above the crown to force a fresh flush of young leaves.
Special Growth to Remove
- The flower stalk / blossom — cut it out early to hold the plant in leaf (the plant’s own care note).
- Any leggy, over-mature seedlings in a sprout tray — cut and use the whole batch rather than letting it stretch and toughen.
Do not strip healthy inner leaves or cut into the central growing point — that is the source of every future harvest.
Container & Small-Space Pruning
Cress is a natural container and windowsill crop — a tray of sprouts on a sunny sill, cut whole with scissors and resown, is its classic use. Grown on for leaves in a pot, take outer leaves and cut the blossom to extend the picking.
Tools
Precision snips or fine scissors are the only tool needed. The cuts are all soft-tissue leaf and stalk work — secateurs, loppers, saws and hedge shears have no role on a leafy annual (shears crush and bruise the crop rather than cut it cleanly).
Tool Hygiene & Disease Risk
Routine for garden plants. For sprout/microgreen trays, hygiene is really about clean water and clean scissors to avoid damping-off and mould — harvest with a clean blade and do not leave cut debris to rot in the tray.
Cut Placement & Technique
Take outer leaves with a clean cut at the base of the leaf stalk, just above the crown, always leaving the central rosette of young leaves intact. For a rejuvenating shear, cut the whole plant back to roughly 3–5 cm, above the lowest leaf bases and the growing point. Cut any bolting stalk right down at its base.
Heavy Pruning & Rejuvenation
Not applicable — there is nothing woody or perennial to rejuvenate. A sprout stand is a single-cut crop; a leaf plant, once bolted, is replaced by resowing rather than cut back.
Post-Pruning Care
After a hard cut-and-come-again shear, water to push the regrowth flush and keep the bed cool and evenly moist — heat and drought stress after cutting simply trigger bolting. No feeding is needed to force regrowth; the crown regrows on its own.
Common Pruning Mistakes
- Letting the blossom develop instead of cutting it early — leaf quality then collapses.
- Leaving a sprout tray too long so the seedlings stretch, toughen and lose flavour.
- Relying on one sowing — cress is a succession crop measured in days, not weeks.
When NOT to Prune
Little applies — there is no structural pruning to withhold. Simply do not delay a sprout harvest or leave the blossom on a leaf crop.
Recommended Tools (by task)
- precision_snips — for cutting sprouts at soil line and removing the blossom; no other tool is relevant to such a small, soft crop.
Propagation Guide
Garden cress is grown from seed and is about the fastest vegetable to germinate — broadcast it thickly on moist soil or a damp pad and it sprouts within a couple of days. It is grown outdoors in cool weather and, as the site notes, indoors year-round for sprouts and microgreens; no vegetative propagation is used. Very easy.
Quick Propagation Specs
| Best Propagation Method | Seed, broadcast on the surface |
| Propagation Difficulty | Easy |
| Seed True-to-Type | Species comes true from seed |
| Best Propagation Season | Autumn to winter in frost-free areas, spring in temperate climates; indoors year-round for sprouts |
| Seed Germination Time | Very fast, often 2–3 days |
| Germination Temperature | Germinates readily over a cool-to-warm range, around 15–20°C (59–68°F) |
| Seed Sowing Depth | Surface to barely covered (about 0.5 cm / 0.25 in) |
Growing from Seed
Seed Handling & Viability
Seed keeps for several years stored cool and dry and needs no pre-treatment. When wetted it turns mucilaginous, which helps it stick to the surface it is sown on.
Sowing & Depth
Broadcast thickly onto the moist surface of soil, a seed tray, or a damp pad of paper or cloth, and leave it on the surface or barely cover it — it does not need burying.
Germination Conditions & Time
Keep constantly damp; seed sprouts within about 2–3 days. It germinates fine out of direct sun, matching the shadier position the plant prefers.
Sprouts & Microgreens
For sprouts and microgreens no soil is needed — sow on a wet pad indoors at any time of year and cut the seedlings within days.
Bloom & Edible Flower Guide
Quick Details
- Bloom Season: Spring to summer
- Time to First Bloom: In its first season – garden cress is very fast, running to flower within weeks of sowing, especially in heat
- Flower Appearance: Tiny four-petalled white flowers with a pinkish hue, borne in slender clusters (racemes)
- Edibility: Edible – the delicate flowers carry the same fresh, peppery bite as the leaves and make a pretty garnish
Detailed Blooming Overview
Garden cress is one of the quickest plants to bolt, throwing up slender spikes of tiny white, pink-tinged flowers soon after the seedling stage. The flowers keep the plant’s peppery character and are a fine addition to salads and sandwiches.
Flower Characteristics
- Tiny four-petalled (cruciform) white flowers with a pinkish hue, held in clusters.
- Followed by small flat seed pods if left to mature.
Bloom Care & Thinning
- Managing the bloom: Cress is usually cut very young; if it flowers, pick the sprigs while the buds are fresh, as leaf flavor grows sharper once it bolts.
- Pollination: Pollinated mainly by bees.
Bloom Health & Protection
- Aphids: Aphids often cluster on flowering shoots and buds; a strong jet of water, insecticidal soap or neem oil keeps them in check.
- Cabbage white caterpillars: These can graze buds and open flowers – a Bacillus thuringiensis (Bt) spray is a targeted, low-impact option.
Fruit & Uses
Garden cress is grown for its peppery leaves and, most commonly, its young sprouts – the sprout is the main edible part, cut as a microgreen. Leaves and sprouts are eaten raw in salads, and the sprouts are also stir-fried.
Quick Edible Specs
| Edible Parts | Leaves; sprouts (young shoots/microgreens) |
|---|---|
| Main Use(s) | Culinary – raw in salad; sprouts in salad and stir-fry |
| Eaten Raw or Cooked | Mostly raw; sprouts also stir-fried |
| Preparation Required | None; rinse. Sprouts can be grown indoors year-round |
| Harvest Season | Frost areas spring–summer; frost-free areas autumn–winter; sprouts any time indoors |
| Time to First Harvest | Very fast; sprouts ready within days of germination |
| Storage | Best fresh; very perishable once cut |
| Safety/Toxicity Caveat | No toxic parts; peppery flavour |
Shoots & Stems
The tender young sprouts – the seedlings cut soon after germinating – are the most-used part, grown quickly indoors on a windowsill year-round. Snip them at the base as a microgreen for a fresh, peppery bite.
Leaves & Greens
On plants grown on to maturity, the green, deeply lobed (pinnatisect) leaves in a radial rosette are edible. Once the plant is established, cut leaves at the base; cutting off the emerging flower stalk keeps the plant leafy for longer.
Preparation, Uses & Safety
Use sprouts and leaves raw in salads, sandwiches and as a garnish, or lightly stir-fry the sprouts. No detoxifying preparation is required and there are no toxic parts.
Pests, Diseases & Troubleshooting
Overview: Garden cress is a fast, cool-season salad brassica, and its pests and diseases are the classic crucifer set: flea beetles and cabbage-white caterpillars chewing the leaves, aphids on the growth, and damping-off and downy/white-rust fungi in wet, crowded sowings. Because it is eaten young and raw, management leans heavily on hygiene, barriers and fast healthy growth rather than sprays.
Quick Troubleshooting Overview
| Issue / Pest | Main Symptom | Primary Solution |
|---|---|---|
| Flea beetles | Many tiny ‘shot-holes’ in young leaves | Fleece/mesh cover; keep moist; grow fast |
| Cabbage white caterpillars | Ragged leaves, green droppings | Mesh cover; hand-pick; Bt |
| Cabbage aphid | Grey waxy colonies on leaves | Rinse; beneficials; soap |
| Slugs & snails | Grazed seedlings, slime trails | Traps, barriers, hand-pick at night |
| Damping-off | Seedlings collapse at soil line | Clean mix; sow thinly; avoid over-wet |
| White rust / downy mildew | White pustules or downy patches on leaves | Airflow; rotation; remove infected leaves |
Common Pests & Management
- Flea beetles (Phyllotreta spp.):
- Symptoms: Tiny black or striped beetles that jump when disturbed and pepper the young leaves with countless small round ‘shot-holes’; heavy attacks check or kill seedlings and ruin the crop for salad.
- Prevention & Control: Cover from sowing with insect mesh or fleece, keep the soil moist and the plants growing fast to outpace damage, and clear crucifer weeds. Yellow sticky traps catch adults; avoid insecticides on a leaf crop eaten raw.
- Cabbage white caterpillars (Pieris rapae / Pieris brassicae):
- Symptoms: Green or velvety caterpillars that shred the leaves and leave dark green droppings, hatching from eggs laid by white butterflies on the undersides.
- Prevention & Control: Grow under fine insect mesh to exclude the butterflies, inspect and rub off egg clusters, hand-pick caterpillars, and treat with Bacillus thuringiensis (Bt) if needed on a crop harvested young.
- Cabbage aphid (Brevicoryne brassicae):
- Symptoms: Dense grey-green waxy colonies on the leaves and growing points, distorting growth and fouling the edible foliage; also spreads viruses.
- Prevention & Control: Rinse off with water, encourage ladybirds and hoverflies, and remove badly infested leaves. Insecticidal soap is a last resort – observe any harvest interval strictly on a salad crop.
- Slugs & snails (Deroceras / Helix spp.):
- Symptoms: Grazed and holed seedlings and leaves with tell-tale slime trails, especially in damp, cool conditions.
- Prevention & Control: Hand-pick after dark, set traps, and use barriers of grit, wool or copper around beds; keep the surface clear of debris.
Diseases & Fungal Issues
- Damping-off (Pythium / Rhizoctonia spp.):
- Symptoms: Seedlings that collapse and rot at the soil line, or fail to emerge, in cold, wet, over-sown or dirty conditions – a frequent problem with dense cress sowings on saturated pads or compost.
- Treatment & Management: Sow thinly in clean containers with fresh mix or clean pads, use clean water, provide airflow and light, and avoid over-wetting. Do not re-use contaminated media.
- White rust (Albugo candida):
- Symptoms: Raised white, blister-like pustules on the undersides of leaves with yellowing above, distorting growth in cool, wet weather; specific to crucifers.
- Treatment & Management: Remove and destroy infected leaves, improve airflow and spacing, rotate away from brassicas, and avoid overhead watering.
- Downy mildew (Hyaloperonospora parasitica):
- Symptoms: Yellow blotches on the upper leaf surface with a greyish downy growth beneath, in cool, damp, humid conditions; disfigures and rots the foliage.
- Treatment & Management: Improve airflow and light, avoid wetting the leaves and overcrowding, remove affected leaves, and rotate crops. A copper fungicide is a last resort but rarely appropriate on a raw salad crop.
Growing Difficulties & Abiotic Problems
- Bolting & bitterness:
- Cause & Symptoms: Cress runs quickly to flower and turns hot and bitter in heat, long days or when stressed for water.
- Correction Strategy: Sow little and often in the cooler parts of the year or in part shade, keep evenly moist, and harvest young for the mildest leaves.
- Leggy, pale seedlings:
- Cause & Symptoms: Stretched, weak, pale seedlings from too little light or too much warmth on the windowsill.
- Correction Strategy: Grow in good bright light at moderate temperature, and thin overcrowded sowings for sturdy growth.
- Drying out / tip scorch:
- Cause & Symptoms: Wilting and browned leaf tips when the shallow-rooted crop dries out.
- Correction Strategy: Keep the growing medium consistently moist, as cress has little reserve; water gently and often rather than heavily.
What Helps – Products & Tools
On a raw salad crop, prevention rules: insect mesh or fleece against flea beetles and cabbage whites, clean containers and fresh mix against damping-off, and slug traps or barriers. Keep Bt for caterpillars and insecticidal soap for aphids as backups, both with strict harvest intervals. Airflow, rotation and leaf hygiene handle the crucifer fungi; reserve copper fungicide only for persistent mildew and rarely on cress. Spray anything in the evening to protect pollinators.
