Saffron Crocus

The number one reason a saffron planting fails outright. Crocus corms are palatable to rodents in a way daffodil bulbs are not, and a bed that simply never comes up has almost always been eaten rather than rotted. Lay hardware cloth over the bed at planting or use buried wire baskets - this is worth doing every single time, because you cannot fix it after the fact.

Chewed husks, shells or hulls scattered under the plant, fruit and nuts vanishing as they ripen, and gnawed or half-eaten windfalls. On new plantings: freshly dug holes and scattered soil, bulbs missing or gnawed, dug-up seed rows, vole runways under the mulch, and gaps in spring where you know you planted.

There is no rescue for what has already been eaten, so this is a prevention problem. Re-cover disturbed plantings with mesh promptly, replant losses inside cages, and trap or exclude persistent diggers where that is legal locally. On a large tree, accept that you will share the crop and concentrate on gathering promptly.

For a crop on the plant, timely and frequent harvest is the real defense - gather daily through the ripening window rather than leaving anything to hang, and pick slightly early to finish indoors where the crop allows it. Net or bag what you can reach. For bulbs and sown seed, lay wire mesh or hardware cloth over the planting, plant deeper, use buried wire baskets, and clear away the papery tunics and debris that advertise a fresh planting. Trunk baffles slow climbers on isolated trees, clearing jumping routes from nearby trees and roofs helps, and removing brush cover reduces the rodents sheltering nearby.

Squirrels, chipmunks, voles and mice are the wildlife that competes with you most directly for a crop. They take ripening nuts, seed and fruit off the plant, usually before you judge it ready, and cache what they do not eat. They also dig up freshly planted bulbs and sown seed, and voles tunnel in to gnaw bulbs and roots underground through winter. They climb anything, they know exactly when a crop is ripe, and a determined pair can clear a small tree or a new planting in a few days.

For saffron this is specifically a summer-dormancy problem, and it is the second great killer after rodents. Corms resting in warm wet soil from June to August rot, which is why the crop fails in humid wet-summer regions but thrives in dry-summer ones. Keep all irrigation off the bed once the foliage dies back, plant raised and gritty, and in wet-summer climates grow in pots you can keep dry.

Wilting in the middle of the day on a plant whose soil is damp - the classic tell, and the reason people water a rotting plant and finish it off. Leaves yellowing from the bottom up, dull off-color foliage, and growth that stalls for no visible reason. Whole shoots, or one side of the plant, collapsing while the rest still looks fine. Soft, dark, or mushy tissue at the base of the stem or at the crown, sometimes with a sour smell. Lift a failing plant and look at the roots: healthy ones are firm and pale, rotted ones are brown or black and slimy, and the outer layer slips off between your fingers leaving a thread of core behind. Seedlings that topple over at soil level are the same problem, called damping-off.

There is no cure for tissue that has already rotted, so act on the conditions rather than looking for a spray. Stop watering at once and fix the drainage - open up compacted soil, or move the plant to a raised, sharply drained position or a container. Lift a badly affected plant, cut away every soft dark root and rotted section with a clean blade back to firm pale tissue, and replant only the healthy parts into fresh free-draining soil or mix. Often the better move is to give up on the plant and save its offspring instead: cuttings, offsets, or divisions taken from firm healthy growth root readily and give you a clean start. Bin the rotted material rather than composting it, and correct the drainage before you replant, because the rot comes straight back in the same wet spot.

Drainage is the whole defense. Match the plant to the site first - something that wants sharp drainage will not survive heavy clay or a low, water-collecting spot however well you tend it. Where the ground is heavy, plant on a raised bed, berm, or slope, or grow in a container. Set plants at the depth they were already growing, since burying the crown or the root flare is a common cause of rot, and keep mulch pulled back a few inches from the stem base instead of piled against it. Water the soil rather than the calendar: check that the top inch or two is dry before watering again, cut back hard in cool weather and winter dormancy, and never leave a pot standing in a full saucer. Do not plant or dig in soggy ground, and go easy on rich amendments for plants that want it lean. Rotate annual crops, and start with clean healthy plants and fresh mix.

Root rot is not one organism but a group of soil fungi and water molds - Pythium, Phytophthora, Fusarium, Rhizoctonia and others - that sit harmlessly in most soils and only turn destructive when the ground stays saturated. Waterlogged soil drives the air out, the roots suffocate, and the weakened tissue is invaded and goes soft, brown, and stringy. Because the damage is underground you usually see it first as something that looks like drought: wilting, yellowing, stunting, a plant that does not respond to being watered. Overwatering, heavy compacted ground, a low spot that collects runoff, a pot with no drainage or a saucer left standing full, and cold wet soil in winter are the usual causes. Once roots have actually rotted there is no cure - this is a problem you prevent rather than treat.