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Spinach Growing Problems: Troubleshooting

Spinach plant1
Spinach plant grow in cool season
Spinach growing problems are often related to growing spinach in the wrong season.

Spinach growing problems are often related to growing spinach in the wrong season.

Grow spinach in cool weather. Sow spinach in the garden as early as the ground can be worked in spring. Make succession sowings every 10 days for a continuous harvest of young tasty leaves. Continue sowing spinach until just a few weeks before the start of summer.

Sow spinach again in late summer for a cool fall harvest. In mild winter regions, sow spinach in autumn for spring harvest.

For spinach growing tips see Spinach Growing Success Tips at the bottom of this post.

Common spinach growing problems with cures and controls:

• Seedlings fail to emerge; poor germination. Seed sown too shallow. High temperatures or dry conditions will cause seed to dry and fail to germinate. Sow seed in cool weather. Keep soil evenly moist to allow for germination.

• Plants are eaten or cut off near soil level. Cutworms are gray grubs ½- to ¾-inch long that can be found curled under the soil. They chew stems, roots, and leaves. Place a 3-inch paper collar around the stem of the plant. Keep the garden free of weeds; sprinkle wood ash around base of plants.

• Seeds rot or seedlings collapse with dark water-soaked stems as soon as they appear. Damping off is a fungus that lives in the soil, particularly where humidity is high. Do not plant in cold, moist soil. Make sure soil is well drained.

• Leaves are faded yellow. Nitrogen deficiency. Spinach is sensitive to inadequate nitrogen. Side dress with compost tea every 10 to 15 days. Add aged compost to planting beds twice each year.

• Plant bolts–flowers and sets seed–before leaves are ready for harvest. Bolting can be brought on by long daylight and very warm temperatures or cool temperatures followed abruptly by very warm temperatures, 80°F or greater. Plant spinach so that it comes to harvest in cool weather. Plant varieties that resist flowering–bolting: Bloomsdale Long Standing, Big Crop, America. Plant spinach in late summer so that plants mature in the cool days of fall.

• Leaves curl under, deformed, and yellowish; small shiny specks on leaves. Aphids are tiny, oval, and yellowish to greenish pear-shaped insects that colonize on the undersides of leaves. They leave behind sticky excrement called honeydew which can turn into a black sooty mold. Remove aphids from leaves with a blast of water from the hose. Use insecticidal soap.

• White thread like tunnels within leaves. Leafminer larvae tunnel inside leaves. Destroy infected leaves and cultivate the garden to destroy larvae and keep adult flies–they are black with yellow stripes–from laying eggs. Cover crops with floating row covers.

• Tiny shot-holes in leaves of seedlings. Flea beetles are tiny bronze or black beetles a sixteenth of an inch long. They eat small holes in the leaves of seedlings and small transplants. The larvae feed on roots of germinating plants. Spread diatomaceous earth around seedling. Cultivate often to disrupt life cycle. Keep garden clean.

• Irregular small holes eaten in leaves. Cabbage lopper is a light green caterpillar with yellow stripes running down the back; it loops as it walks. Keep garden clean of debris where adult brownish night-flying moth can lay eggs. Cover plants with spun polyester to exclude moths. Pick loppers off by hand. Use Bacillus thuringiensis. Dust with Sevin or rotenone.

• Leaves are chewed. Snails and slugs feed on leaves. Hand pick at night when these pests feed or set out saucers of beer at soil level to attract and drown slugs and snails.

• Leaves and stems are partially defoliated. Armyworms are dark green caterpillars the larvae of a mottled gray moth with a wingspan of 1½ inches. Armyworms mass and eat leaves, stems, and roots of many crops. Armyworms will live inside webs on leaves. Handpick caterpillars and destroy.

• Plant yellows on one side; plant is stunted are stunted. Fusarium wilt or fusarium yellows, also called spinach yellows, is a fungal disease which infects plant vascular tissues. Fungal spores live in the soil and can be carried by cucumber beetles. Plant disease-resistant varieties. Rotate crops. Remove and destroy infected plants.

• Veins in leaves yellow. Spinach blight or spinach yellows is a mycoplasma disease spread by leafhoppers. Remove infected plants. Control leafhopper. Keep the garden free of weeds which can harbor disease.

• Small yellow spots on outer leaves with brown centers enlarge; spot may drop out leaving a ragged hole. Cercospora leaf spot is a fungal disease spread by heavy rainfall and warm temperatures. Keep weeds down in the garden area; they harbor fungal spores. Avoid overhead watering.

• Round water-soaked spots on leaves turn reddish brown to black. Anthracnose is a fungal disease that spreads in high humidity and rainfall. Leaves may wither and fall. Plant may die back. Spray or dust with a fixed copper- or sulfur-based fungicide every 7 to 10 days. Remove and discard infected plants. Avoid working in the garden when it is wet which can result in spread of spores. Keep tools clean.

• Irregular pale green to yellowish to brownish spots on upper leaf surfaces; grayish powder or mold on undersides. Downy mildew is a fungal disease often triggered by wet and humid weather or too frequent overhead irrigation. Improve air circulation. Plant resistant varieties. Rotate crops. Keep garden free of plant debris that can shelter fungus spores.

Spinach Growing Success Tips:

Planting. Spinach is a cool-weather crop that grows best in full sun. Where the weather is very warm, grow spinach in partial shade. Grow spinach in rich, well-drained soil; add aged compost to the planting bed before planting. Spinach will germinate poorly where soil temperatures exceed 75°F. Once seeds germinate and begin to grow, mulch the soil to maintain an even, cool soil temperature.

Planting time. Sow spinach in spring as early as 8 weeks before the average last frost date. For best flavor, spinach should come to harvest before day time temperatures exceed 70°F; increased day length also will cause spinach to flower and set seed. • For a fall crop, sow spinach in late summer 8 weeks before the first expected frost. • For an early spring harvest, sow spinach in fall about 6 weeks before the first expected frost and then protect plants from freezing in winter (plants will grow before the first freezing temperatures then stop and go nearly dormant through the winter). When spring arrives, these plants will complete their growth and be ready for harvest. In mild winter regions, sow spinach every 2 to 3 weeks throughout the fall.

Care. Keep spinach evenly moist and mulch planting beds to keep the soil cool. Protect seedlings from flea beetles, aphids, and leafhoppers with floating row covers. Thin plants to 6 inches apart for best growth and to maintain good air circulation. Keep the garden free of plant debris that can harbor pests.

Harvest. Begin picking spinach leaves when the plant has formed 6 to 8 leaves; harvest the whole plant when leaves are 4 to 6 inches long.

More tips at How to Grow Spinach.


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  1. The center or my silverbeet leaves are turning dark green and are curling all the way around. The stems turn a red hue or even brown. They have stopped growing. The leaves are not dry yet they are brittle to touch. The outer leaves are fine but when you cut to eat you can not get the rest as they are affected. I have started a new crop and transplanted the good ones that are left only to find that they are also being affected, I have planted rocket with them and they are suffering the same fate, Could you please help?

  2. The leaves of silverbeets–also called Swiss chard and perpetual spinach–can turn dark green from a bronze color as the weather warms. Silverbeet leaves can turn a bronze-red color as the weather grows colder in autumn to winter; in spring the opposite occurs–new foliage will grow green and older foliage will revert from bronze to green as the temperatures climb. This is the plant leaves’ reaction to temperature.
    But clearly, your silverbeets have a bigger problem: the stems which are usually white or cream colored are turning red to brown and this is spreading to the leaves. Moving the plants has not helped.
    I suspect that the problem is a fungal disease called Cercospora leaf spot which causes stalks and then leaves to have reddish or brown spots. Cercospora leaf spot is usually marked by spots or streaks with tan centers and dark red margins and leaves curl–as you have described. The disease usually starts with new growth and spreads to the older leaves too.
    Cercospora fungus can live on in the garden and in the soil for 2 years–it can overwinter in garden debris, the soil, and in infected seed. A crop rotation of at least two years will help break the disease cycle, but also improving the drainage of your garden soil is essential. Too much moisture in the soil and not enough organic matter–rich compost–can help the fungus to thrive. So add plenty of aged compost to your garden. Also space your silverbeets further apart in rows wider than normal and plant your silverbeets on ridges so that rainwater and dew will evaporate quickly. As well, you can spray the leaves with compost tea early on so that the fungus can not get a start. For your existing plants, clip away infected leaves as soon as you spot the problem. Leaves not affected can be harvested and eaten.

    • There are no spots on our silver beet leaves but the new growth is dark and curling inwards and is quite brittle – also stunted. The plants were all growing really well until the last few days – I fear the whole lot will go down. Help!

  3. Thanks for the information. . . I have about 30 seedlings that have been about an inch tall for 4 weeks. no further growth. I have no clue whats going on. Do you have any insight?

    • Slow or not growth–but not other problems–is commonly an indication that the soil is too chilly. When air and soil temperatures rise, growth will kick in.

    • Mushrooms thrive in acidic soil. Avoid adding compost that is not fully aged or decomposed. Do a simple soil pH test and then follow the directions on your pH test kit to correct the pH. Lime, in either the ground or powdered form, is commonly suggested to raise pH. The amount of lime needed will depend on the soil texture (more is needed for clay than for sandy soil). Wood ashes and oyster shell also make acid soil more neutral.

    • There are several small caterpillars that feed on spinach–cabbage loopers, alfalfa loopers, armyworms, and corn earworms are some. Exclude the moths that lay caterpillar eggs by protecting your crop with row covers. Handpick the pests off the plants or spray with neem or horticultural oil to kill the pests already gathered on your crop.

      • My spinach is just getting small holes on leaves. Leaves are about 5″ tall an very wide with small leaves on the inside. I just cut all the big leaves off because of the holes. A very tiny green caterpillar no stripes on its back that I can see. Lots of holes appearing. Can I spray them with mint leaves ground-up or with dish soap? Would either of these help? The plants are in containers that are 15″ off the ground with netting over the top of them. What else can I do? Only want non chemicals that will not hurt us or my plants. HELP please.

        • You can spray your plants with water from the hose; this may knock off the caterpillars or other insects. You can also spray with an insecticidal soap: mix a tablespoon of liquid soap with a quart of water in a spray bottle (do not use detergent which may damage your plants).

    • Adding aged compost to planting beds on a regular basis–2 inches or more twice a year–should give your soil all the nitrogen plants will need. Commonly fungal diseases are associated with poor draining soil (compost will help your soil be well-draining) and overhead watering. Water at the base of plants, not overhead. Add compost to planting beds.

    • Silverbeet–also called Swiss chard and chard–commonly has what is called a simple leaf. What you describe is a compound leaf–that is several leaflets growing from the same petiole or stem. It may be that your mother’s silverbeet has a deeply lobed leaf that appears similar to a compound leaf–the lobes are connected by a narrow bands of blade tissue–and so they are still a simple leaf. When leaflets have separate stalks that are joined at the point of union with the main leafstalk, the leaf is considered compound. That would be unusual for a silverbeet, but certainly not impossible.

    • Cucumbers can become soft if under-watered or allowed to stay on the vine too long. Keep the soil evenly moist, not wet, but do not let it dry out. Harvest at or about the number of days to maturity. Feed cucumbers with calcium and magnesium which will strengthen cell walls.

    • Spinach leaves yellowing: the most common cause would be nitrogen deficiency; feed the plants with a dilute fish emulsion fertilizer; other possible problems are root rot usually caused by a soil fungal disease–lift a plant to see if the roots are water-soaked and brown; add aged compost to the planting beds to ensure drainage; a viral disease can cause leaves to yellow–remove the plants; check to see if there are leafhoppers on the plants; leafhoppers spread viral diseases such as cucumber mosaic virus.

    • As soon as spinach is cut from the plant, the living cells immediately begin to decline and soon decay. The decay is dark colored. Use spinach quickly after harvest or refrigerate it.

  4. In 2018, I dedicated a 6 x 6 raised bed to Bloomsdale Long-Standing and scattered seed. Germination was good and bed was thinned appropriately. Plants slowly grew a few true leaves and then stopped growing. I left them alone and sometime in the season, one plant grew beautifully and I harvested spinach from it well into the summer. The others just sat there. I have the same problem with transplants that I purchase. They just don’t grow but otherwise look fine. I have since tried other varieties of spinach with the same result. I have rich soil with compost. I’m In Coos Bay on the Oregon coast at about elevation 50. I’m just really curious as to why one plant did well out of many. None of the plants looked unhealthy. I have long, cool summers so this seems like crop that should thrive.

    • If both seeds and transplants have done poorly in the same bed, the likely problem is either sunlight or soil, or both. Near the coast, spinach can be planted in full sun. If the soil has not been changed in the last year, it may be time to replace the soil. Replace in full or add commercial organic planting mix to the bed; that should eliminate any soilborne organisms that may be affecting the plants. Do not fertilize apart from add B1 or another starter fertilizer.

  5. A couple of days ago my spinach was growing well and had bountifully of baby spinach leaves, approx 4-6 on each plant.
    However I went to them this morning and they all look ‘sad’. As in a most wilted and not standing high anymore, almost resting on each other?

    • Be sure the soil is just moist, but not wet, and do not let the soil dry out. The roots are still shallow and must have moisture. Also protect the seedlings from cold nights.

    • New Zealand spinach is a vining plant; true spinach is not a vine. If you are growing true spinach, it is likely the plant is stressed.

  6. My Bloomsdale Long Standing spinach is starting to bolt. (We’ve had a lot of hot weather lately.) At the juncture of each leaf with the stem, there is a whitish hairy growth — like hair under an armpit — a ball of straight spikes of “hair” growing out in all directions, each spike about 1/8 of an inch or so in length. The spinach leaves are not yet bitter tasting, so I would like to eat the spinach, but I wonder if these hairy growths are edible. Are they just another manifestation of bolting (besides the early flower buds), or are these something else?

    • The white filaments could be mold–which is possible if the weather has been humid or wet–or they could be mealy bugs. You can crush mealybugs with your fingers or spray them neem oil. Given that the plants are bolting, you should harvest. You can harvest the leaves and leave the white mold or bugs behind.

  7. Thank you, Steve, for your prompt reply. There is nothing that looks like a bug. I am pretty sure these “hairs” are filaments grown from the spinach plant itself. There does not seem to be a way of attaching a photo to this message, otherwise I could show you what they look like.

    • There is a disease called “spinach white rust”; it looks a bit like downy mildew which can look a bit like white filaments. The disease looks like downy mildew to start, then the leaves become chlorotic and then they develop small blisters. This disease usually happens in cool weather. It can be treated with a fungicide.

  8. A fAew years ago I showed spinach on my allotment. Now every year new spinach plants grow nearby. I have some really nice looking spinach this year but is it safe to eat? I think the plants from last year have set their own seed.

    • If the spinach reseeded, and you are sure it is spinach, then it should be safe to eat. Nature sowed the seeds saving you some time and effort.

  9. My plants were fine as I managed to harvest twice already however I noticed recently that my spinach leaves are being eaten to the stem where only the stems remain with no green foliage.No sign of bugs nor worms. Please help……….

    • You likely have night visitors such as snails, slugs, or earwigs. You can sprinkle diatomaceous earth around the plants as a barrier. If you suspect birds or squirrels are eating the plants, cover them with a floating row cover. Ask for these items at a garden center.

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