Gadenin日本語Get the appBirds are the main pest, and they arrive before you expect them
Proso is the round white grain in commercial bird seed, and the local bird population knows this perfectly well. Sparrows, finches and doves find a ripening block within a day or two of the first hard seed, and because the panicle is open and drooping they can work it comfortably from a perch on the stem. A small garden bed can be stripped in under a week, and the birds take the ripest seed first, which is the seed you most wanted.
The defense is netting, and it has to go on before the grain hardens, not after you notice damage. Drape fine mesh netting over hoops or a simple frame so it stands clear of the heads; netting laid directly on the crop lets birds perch on top and feed straight through it. Tuck the edges down to the soil, because ground-feeding birds walk in from the side rather than landing on top. Reflective tape and scarers work for about three days and then stop working.
The other defense is timing. Cutting at two thirds hard and finishing the crop under cover removes the crop from the birds a full week or more before they would otherwise finish with it. Most bird loss in a garden happens in the week that a gardener spends waiting for the base of the head to ripen.
| Problem | What you see | When it appears | What to do |
|---|---|---|---|
| Bird feeding | Heads visibly thinned from the tip, seed scattered below | From the first hard seed onwards | Net over hoops before hardening; cut early and cure under cover |
| Head smut | Head emerges as a dark, sooty mass instead of grain | At heading | Pull and bin affected plants whole; do not compost or save seed |
| Lodging and stem rot | Block flat, stem bases brown and soft after rain | After a storm, mid to late season | Cut the affected area early and cure it separately |
| Damping off and seedling loss | Gappy row, seedlings collapse at soil level | First two weeks | Sow shallower into warmer soil; stop the daily watering once up |
| Aphids on stems and heads | Colonies in leaf axils, sticky honeydew, sooty film | Hot dry spells | Hose off; usually outrun by the crop, rarely worth treating |
| Shattering loss | Grain on the soil, thin heads, volunteers next spring | Late ripening | Cut at two thirds hard, in the morning, into a container |
Smut in the head
The most distinctive disease of proso is a smut that replaces the developing grain with a mass of dark, powdery spores. You do not see it at all until the head emerges, and then it is unmistakable: instead of a green panicle that will fill with seed, the plant pushes out a sooty gray-black club. There is no treatment once it appears, and the affected plant produces nothing.
It matters because it is seed-borne and soil-borne. The spores from an infected head contaminate the surrounding soil and any seed you harvest from the block, so a small outbreak this year becomes a larger one next year if you save seed from that bed. The response is to pull affected plants whole, as soon as you see them and before the head starts releasing spores, and to put them in the bin rather than the compost pile.
Prevention is hygiene and rotation. Do not save seed from a block where you saw smut, even from clean-looking heads, and move the crop to a different bed for two or three seasons. Be scrupulous about volunteers there, since a self-sown plant carries the problem through your rotation.
Lodging, and the rot that follows it
A flattened block is not itself a disease, but it reliably becomes one. Once the stems are down, the base of the crop sits in still, damp air against wet soil, and within a week of rainy weather you find brown, softened stem bases and a musty smell. Grain on rotted stems stops filling and the heads that are touching soil pick up mold that will spoil a whole batch if you cure them with the rest.
Almost all lodging is self-inflicted. Too much nitrogen makes soft tall stems; too thick a stand makes thin ones; watering after the grain has started to harden softens the ground so the whole plant leans. Fix those three and the crop mostly stands. On an exposed site, mounding soil along the rows and running twine down each side of the block also help.
If the block does go down, act rather than wait. Check the stem bases after any wet spell, and if you find browning or softening, cut that section immediately even if it is only halfway ripe and hang it separately under cover. Half-ripe grain cured properly is worth a great deal more than fully ripe grain that molded on the ground.
Seedling failures and thin stands
Most complaints about proso not coming up are sowing problems rather than pest problems. Seed put in an inch and a half (4 cm) deep is too deep for a grain this small and never reaches the surface. Seed sown into ground below 60F (16C) sits for a fortnight and is eaten by ants and ground beetles before it germinates. Seed sown into a fluffy, unfirmed bed sits in air pockets and never makes contact with moist soil.
Where seedlings do come up and then collapse at soil level, that is damping off, and it follows from keeping the surface constantly wet after emergence. The daily sprinkle that gets a shallow-sown crop germinated must stop as soon as the row is green. From that point proso wants deep, infrequent water, and a surface that dries between waterings is what keeps the seedling collar healthy.
Cutworms will take a few seedlings in newly broken ground, showing as plants cleanly severed at soil level. In a bed sown thickly and thinned back this is rarely worth acting on, and it is one more argument for sowing more seed than you need.
- Walk the block twice a week from heading onwards Look specifically at the tips of the heads for thinning, which is the first sign of bird feeding, and at the base of the stems for browning after rain. Both problems are cheap to fix in the first few days and expensive a week later.
- Pull and bin any smutted head the day you see it Take the whole plant, roots and all, and carry it out of the bed in a bag rather than shaking it. A sooty head releases spores freely, and walking one across the plot spreads next year's infection over ground that was clean.
- Net before the grain hardens Put fine mesh over hoops as soon as the heads have finished flowering and are beginning to fill, keeping the mesh clear of the heads and pinned to the soil at the edges. Waiting until you see damage means you have already lost the best of the crop.
- Cut anything that has gone down and started to rot Do not wait for a lodged, browning section to catch up with the rest of the block. Cut it, bundle it loosely, and hang it separately so that if it does carry mold it cannot spoil the sound bundles beside it.
Proso is a short-season crop, and time is the most effective control you have. A block that goes in on warm soil, grows fast and is cut at two thirds hard passes through most of these problems before they can develop.
Keep a record of what turned up and when
Write down the date you first saw bird damage, the date you first saw a smutted head, and where in the bed the block lodged. All three are strongly tied to place and timing, and a two-season record turns each of them from a surprise into a scheduled job: net on this week, avoid this bed, stake the windward end.
Record the bed as well, by name or on a plot sketch, and carry that record forward for at least three years. Both smut and volunteers are rotation problems, and the only way to rotate properly against them is to know exactly where proso stood in each of the last few seasons.