Gadenin日本語Get the appWhy this crop is mostly trouble-free
One of the reasons to grow this instead of true spinach in summer is that it barely gets anything. It is not troubled by the downy mildew, leaf miners and heavy aphid pressure that make real spinach miserable in warm weather, and it is unrelated to spinach, so it does not even share their diseases. The list of things that actually go wrong is short.
That short list has a pattern worth learning, because it changes where you look. Trouble on this plant is at ground level, not at the growing tips. The seedling stage, the underside of the sprawling mat and the crown are where problems start, and a weekly look under the stems catches nearly everything early.
The other thing that ends a crop is not a pest at all. This plant has no frost tolerance and takes damage well above freezing, so knowing chill damage from disease saves you treating something that only the weather caused.
| Problem | First sign | Where you see it |
|---|---|---|
| Slugs and snails | Ragged holes, slime trails | Seedlings, and stems lying on damp soil |
| Stem and leaf rot | Soft brown patches, sour smell | Underside of the mat on wet ground |
| Aphids | Clusters on the softest growth | Shoot tips and young leaf undersides |
| Leaf miner | Pale winding tunnels inside the leaf | Older, larger leaves |
| Chill damage | Dark water-soaked collapsed patches | Whole plant, after a cold night |
| Damping off | Seedling collapses at soil level | Pots and cold wet seedbeds |
The seedling stage is the vulnerable one
Germination here runs over two weeks and the seedlings are slow to get going, which means there is a long window when a small number of slugs can clear a whole row overnight. Once the plant is established and running it shrugs them off entirely, but until then it needs looking after. This is the single most common way a sowing of this crop fails after the seed has done its part.
Damping off is the other seedling problem, and it is a cold and wet problem rather than a bad luck one. A seedling that keels over with a pinched, darkened stem right at soil level has damping off, and it happens in cold soggy seedbeds and in overwatered pots with no air movement. Warm soil and restrained watering prevent it; nothing cures a collapsed seedling.
Both arguments point the same way, which is not to sow early. A sowing into soil above 60F (16C) germinates faster, grows away faster and spends far less time in the fragile stage where these two problems live.
- Clear slug shelter before sowing Take away boards, pots, dense weeds and thick mulch within a couple of feet (60 cm) of the row. Slugs feed at night and shelter close by during the day, and removing the shelter does more than any treatment.
- Check the row at night Go out with a torch an hour after dark two or three times in the first fortnight. You will see immediately whether slugs are the cause of the damage, and hand collecting at that point protects the whole sowing.
- Do not mulch until the plants are up and running Mulch is valuable later but it is perfect slug habitat right next to seedlings. Wait until the plants have made six inches (15 cm) of growth, then mulch around them rather than over them.
- Water pots from below and sparingly Keep seed pots just moist rather than wet, give them air movement, and use fresh compost. Cold saturated compost with a still surface is exactly the condition damping off needs.
Because emergence is uneven, protect the row for a full month rather than until the first seedlings are up. Late emergers are just as vulnerable as the early ones were.
Rot under the mat, and pests on the tips
Once the plant sprawls, the stems on the ground are the weak point. Where a thick succulent stem lies on wet bare soil it will either root at the joint, which spreads the plant, or it will go soft and brown and rot, which spreads through the surrounding leaves. In humid weather a dense mat holds moisture underneath all day, and by the time you notice from above there is a patch of slime under it.
The answer is airflow and a dry surface underneath. Mulch under the plant so the stems rest on straw rather than mud, lift the mound onto a low frame or a few wires if you have the option, and lift and look under it once a week during any long wet spell. Cut out soft brown stems back to sound tissue and take them out of the garden.
The above-ground pests are minor by comparison. Aphids gather on the softest tips in warm weather and are best dealt with by picking, since the tips you would remove are the ones they are on, and a jet of water clears the rest. Leaf miner tunnels appear in older leaves occasionally; pick off the affected leaves and bin them. Neither of these gets on top of a plant that is being harvested twice a week.
| Symptom | Likely cause | Action |
|---|---|---|
| Soft brown slimy stems underneath | Rot from lying on wet soil | Cut back to sound tissue, mulch or lift the plant |
| Yellow collapsing leaves in the middle | Shaded and permanently damp | Thin the stems to open the mound up |
| Sticky curled shoot tips | Aphids | Pick those tips, then hose the rest off |
| Pale tunnels in older leaves | Leaf miner | Remove and bin the affected leaves |
| Plant spreading from rooted joints | Stems rooting where they lie | Cut those stems out at the crown |
| Whole plant limp on damp soil | Crown rot at the base | Pull it, improve drainage, do not replant there |
Cold, and the weediness at the end
This plant has no frost hardiness at all and does not need a frost to suffer. Nights in the mid-40s F (around 7C) stall it, and the first real frost turns the whole thing to dark mush overnight. There is nothing worth attempting in the way of protection for a plant this size and this tender. Recognize the end and take a final large harvest rather than waiting for a warm week that is not coming.
The bigger issue at the end of the season is seed. Any capsule that has been left in a leaf joint and allowed to harden will fall, and those capsules are exactly as durable in the soil as they are in the packet. They survive winter easily, they germinate the following summer, and they can keep coming up for several years from one neglected plant. This is how a well-behaved crop turns into a weed in a bed you wanted for something else.
Clearing properly is therefore the last real job. Cut the plant down, take the whole thing off the bed rather than digging it in, and rake or sweep up the capsules on the soil surface. Do not put capsule-bearing material into a compost pile you intend to spread on the garden, because you will simply be sowing it somewhere new.
- Take a final harvest at the first cold nights When nights are heading for the mid-40s F (around 7C), pick everything usable in one go. The leaves are still good at that point, and waiting for more will cost you the lot to the first frost.
- Lift the whole plant, do not dig it in Cut at the crown and carry the top growth off the bed in one piece where you can. Digging in a plant carrying capsules buries seed at exactly the depth that germinates well next summer.
- Clear the fallen capsules Rake the soil surface and pick up the hard brown capsules. They are large enough to see and gather, and every one you remove now is a seedling you do not weed out next year.
- Write down what went wrong and where Record which plant rotted or was worst hit, the date you first saw it, and where the bed held water. That note tells you next spring whether to move the bed, mulch differently or lift the plants onto a frame.
Volunteers pull easily at the two-leaf stage and are hard work once they have started to run. A single pass over the bed in early summer settles the whole matter, and it is worth doing even in beds where the crop has not grown for a year or two.