How to Grow Mesclun in Australia

Mesclun is not one plant but a way of growing salad: a mix of leaves sown thickly together, cut young and left to regrow. The Heirloom Mix blends lettuce (Lactuca sativa), endive (Cichorium endivia), rocket (Eruca sativa), Brassica juncea and Brassica narinosa, from the daisy and cabbage families. Sown in the cool months it gives salad within weeks, and the usual mistake is sowing it into summer heat.

Three mistakes that matter

1. Sowing into summer heat. Lettuce seed can stay dormant in soil above 25°C, and heat pushes the whole mix to flower, which turns the leaves bitter. Sow in the months given in When to plant.
2. Letting the patch dry out. Tender leaves need fast, unchecked growth, and the shallow roots cannot find water once the top few centimetres dry. A dry spell brings bitterness and early flowering, so water before the surface dries.
3. Cutting below the crown. The growing point of each plant sits just above the soil, and a cut through it ends regrowth. Cut about 2.5 cm above the soil with scissors, and the patch can come again.

When to plant

Sow when the soil sits between about 10°C and 25°C, the range that suits both lettuce and rocket. Most lettuce seed will not germinate once the soil reaches 30°C. A small patch sown every two to three weeks keeps leaves coming without a glut.

At the warm edge of a window, water the bed the day before sowing, because evaporation cools the soil. Then cover the patch with 30% shade cloth. At the cold edge, throw frost cloth over young sowings on frosty nights.

Site, soil and setup

A patch a metre square is plenty to start with, close enough to the kitchen to cut for each meal. What it needs is rich, crumbly soil that holds moisture and still drains, in sun through the cool months.

Heavy feeding with liquid fertiliser brings soft growth that draws snails, so let the compost do most of the work. Test the soil first if lime is in question: see soil pH explained.

Container growing

Mesclun suits pots better than most crops, because it is cut young and does not need deep roots. Use a pot or trough at least 30 cm across, holding 10 to 15 L, or a recycled polystyrene box with drainage holes. Fill it with premium potting mix, never garden soil; the Heirloom Mix is sold for pot growing.

• Water: pots dry fast, so check every day and water before the mix dries out.
• Feed: fish and seaweed blend at 25 mL per 9 L fortnightly, and after each cut.
• Position: full sun in winter; move the pot to morning sun only as spring warms, for example on the east side of the house.

See watering pots in an Australian summer for the hot months.

Sowing Seeds

Sow direct where the patch will be cut, scattering the seed thinly over the surface or in close rows.

Sowing direct

• Water the bed the day before, then rake it level and fine.
• Scatter the seed thinly over the patch, or sow in rows 8 to 10 cm apart.
• Cover with 3 to 5 mm of fine soil or seed-raising mix; lettuce seed needs only the thinnest covering.
• Firm the surface with the back of a rake and water with a fine spray.
• Keep the surface damp until seedlings appear, usually in 7 to 14 days.

A pre-mixed packet sows every type together, and they grow at different speeds. The brassicas usually race ahead, so an even first cut keeps the slower lettuces in the light.

Care by growth stage

Moisture is the lever here: anything that slows growth makes the leaves tough and bitter. Weeks count from sowing.

If regrowth stalls in poor soil, a light dose of all-purpose controlled release granular (NPK around 14-5-10), scratched in between cuts, can help. In warm, humid districts, water less often and only in the morning, since leaves left wet overnight invite rot and downy mildew.

Thinning

Even a thick sowing needs thinning where seed has landed in clumps, because crowded seedlings stay damp and rot. Thin once, early, and eat the thinnings.

• Thin when seedlings are 2.5 to 5 cm tall.
• Leave the rest 2 to 3 cm apart each way.
• Snip unwanted seedlings at soil level with scissors, so the roots of their neighbours stay put.
• Take out the fastest brassica seedlings first where they crowd the lettuces.

Companion planting

The best neighbours are quick crops that share the cool season, or tall ones that cast afternoon shade as the weather warms.

Grows well with

• Radish, which crops and clears just as fast.
• Dwarf beans, low enough not to shade the patch.
• Carrots and beetroot, slow to fill their rows, leaving room for a patch between them.
• Sweet corn, whose tall stems shade a patch on their east side through summer.

Keep apart

• Old cabbage-family plants left to flower, which carry aphids and caterpillars onto the rocket and brassicas.
• Pumpkin and zucchini, whose sprawling vines smother a low patch.

Harvesting Leaves

Start cutting when the leaves are 5 to 10 cm long, often 4 to 6 weeks from sowing.

• Cut in the early morning, before the heat wilts the leaves.
• Snip with scissors about 2.5 cm above the soil, clear of the growing crowns.
• Clear-cut one block at a time, or take only the outer leaves for a smaller picking.
• Water and give a liquid feed straight after each cut.
• Expect the block to be ready again within about a month.
• Once flower stalks rise and the leaves turn bitter, pull the patch and compost it.

Rinse the leaves in cold water and drain them on a towel. Wrapped in a slightly damp tea towel inside a sealed bag in the fridge, they keep for several days.

Toss them raw as a salad, or wilt them into warm dishes and stir-fries.

Common problems

Patchy germination. Seed sown into hot soil, buried too deep or left to dry out comes up thinly. Sow shallow into a pre-watered bed and keep it damp. Read more

One type takes over. The brassicas outgrow the lettuces and shade them out; cut early and evenly, and thin the brassicas first.

Hot or bitter leaves. Rocket grows spicier and endive more bitter as leaves age, so cut young; heat and dry soil make it worse, as Three mistakes explains.

Rot in the middle of the patch. Water trapped in dense rosettes in humid weather rots the leaves; thin the patch and water less in humid spells.

The patch tires. A patch often gives three or four cuts before regrowth slows and the leaves toughen, so keep a fresh one coming.

Pests and diseases

Snails are the worst pest of young salad leaves, and the mix brings the pests of two plant families with it.

Common garden snail (Cornu aspersum) and grey field slug (Deroceras reticulatum). Both chew soft seedlings and young leaves overnight, worst in damp weather. Hunt them by torch after dark, and if a bait is needed, choose an iron-based one, which is far safer for pets and wildlife. Read more

Currant-lettuce aphid (Nasonovia ribisnigri). Greenish to yellow-green aphids about 2.5 mm long feed deep in the rosettes of lettuce and endive. They are found across Australia's lettuce-growing districts. Hose them off, or coat the leaf undersides with insecticidal soap. Read more

Cabbage white butterfly (Pieris rapae). Its velvety green caterpillars chew ragged holes in rocket and the other brassicas, alongside the smaller caterpillars of the diamondback moth (Plutella xylostella). Cover the patch with fine insect mesh from sowing, and use a Bt spray (Bacillus thuringiensis) if caterpillars get through. Read more

Downy mildew (Bremia lactucae). Yellow, angular spots on top of lettuce and endive leaves, with white growth underneath, in cool, damp weather. Remove affected leaves, keep foliage dry overnight, and do not sow a fresh patch beside a diseased one. Read more

Damping off (Pythium species and Rhizoctonia solani). Seedlings rot before they emerge or collapse at soil level soon after, worst in thick, wet sowings. Sow thinly into free-draining soil, avoid overwatering and thin crowded spots. Read more

Prevention first

• Water in the morning, at the base of the plants.
• Thin crowded seedlings so the patch dries quickly after rain.
• Pull and compost each patch once it is finished, before it can pass pests to the next.
• Rotate the patch, and leave two to three years before sowing salad where downy mildew struck.

Tips

1. For full heads and big leaves, grow the single crops instead: see How to Grow Lettuce, Rocket, Mustard and Cress. Endive, chicory and mizuna also grow well on their own.
2. Mix the seed with four to ten parts of dry sand before scattering, so it spreads thinly: see the sand trick.
3. Anzac Day is a fair marker for the main autumn sowing across the south, with a second round as soils warm in early spring.
4. Crisp slightly wilted leaves in cool water for 10 to 15 minutes before serving.
5. Scatter a few calendula petals over the bowl for colour.