Growing Molokhia From Seed: Soil Temperature, Sowing Depth and Thinning

Wait for real heat, not for the calendar

Jute mallow, sold in English as molokhia or Egyptian spinach, germinates on soil temperature and nothing else. Below 65F (18C) the seed sits in the ground and slowly rots. At 77 to 86F (25 to 30C) it comes up in four to seven days, evenly and strongly. That is a narrow, demanding requirement compared with almost anything else in a vegetable garden, and it is the single most common reason people report a dead packet.

Sow it a few weeks after you would sow beans, once nights are reliably warm and the surface of an unmulched bed feels warm to the back of your hand in mid-morning. There is no advantage in being early. A sowing made into cool soil is usually overtaken by one made two or three weeks later into warm soil, because the late sowing never sits still.

This is a crop that carries the hottest weeks of the year, when lettuce has bolted and true spinach is finished. Sowing it into the tail of spring wastes that advantage. Treat the heat as the point of the plant rather than as something to get ahead of.

Softening the seed coat

The seed is small, angular and dark, with a hard coat that sheds water. Untreated, a packet will trickle up over three weeks with maybe half of it never appearing. The fix takes a minute. Pour water at about 140F (60C) over the seed, let it stand until the water cools, then leave it soaking for a further twelve to twenty-four hours. Seed that has taken up water looks visibly plumper and sinks; floaters are usually empty.

Sow the soaked seed the same day, while it is still swollen. Do not let it dry out again and do not soak it for two full days, which drowns the embryo. If you would rather not use hot water, rubbing the seed briefly between two sheets of fine sandpaper works just as well and is easier to judge.

Soaked seed is slippery and clumps together. Roll it in a little dry sand before sowing so you can see what you are doing and spread it thinly. Sowing thickly is a genuine problem with this crop because the seedlings are fine-stemmed and damp off readily when crowded.

The seed of jute mallow is toxic and should never be eaten or used as a sprouting seed. Keep soaking jars labeled and out of the kitchen, and keep leftover packets where children and pets cannot reach them.

Depth, spacing and thinning

The seed is small, so it must go in shallow. A quarter of an inch (6 mm) is right, and on heavy soil an eighth of an inch (3 mm) with a scatter of fine compost over the top is better. Buried an inch deep it will not reach the surface. Keep the top half inch of soil damp until emergence; on hot days that can mean a light watering morning and evening for the first week, and it is the only stage of this crop that needs fussing over.

1. Sow into a shallow drill Draw a drill a quarter inch (6 mm) deep, water the bottom of it, then sow along it at roughly one seed per half inch (12 mm). Cover with fine soil or sifted compost and firm gently with the flat of your hand so the seed is in contact with damp soil.
2. Thin at the second true leaf Once the seedlings have two true leaves, thin to about four inches (10 cm) apart for a dense stand you will cut repeatedly, or eight to twelve inches (20 to 30 cm) apart if you want tall, branching individual plants. Snip the rejects at ground level rather than pulling, so you do not disturb the neighbors.
3. Space rows a foot apart Twelve to sixteen inches (30 to 40 cm) between rows is enough. The plants grow upright rather than sprawling, and a slightly close stand shades the soil, which keeps it moist and suppresses weeds through the hottest part of the season.
4. Record the sowing date and soil temperature Note the date you sowed, the soil temperature at two inches (5 cm) and the date the first seedlings appeared. Two seasons of those three numbers will tell you exactly how early you can risk sowing on your own ground, which no general guidance can do for you.

Direct sowing versus raising transplants

Direct sowing is the better option wherever the season is long enough, because the seedlings put down a taproot early and resent having it disturbed. A direct-sown stand will usually overtake transplants of the same age within a fortnight.

Where summers start late, raise plants under cover for three to four weeks to buy time. Use deep cells or small pots rather than shallow trays, sow two or three seeds per cell and thin to the strongest, and move them out only once night temperatures stay above 60F (16C). Plant at three to four true leaves, before the taproot circles the bottom of the cell. A rootbound molokhia transplant tends to flower early and short, which is exactly what you do not want.

Whichever route you take, do not plant into cold, wet, freshly manured ground. This crop wants warmth, drainage and a soil that has already settled. Raised beds and dark mulches both help by lifting soil temperature several degrees during establishment.