Why do tomato seedlings wilt and develop root rot after transplanting, and can they still survive?

Did your newly transplanted tomato seedlings suddenly wilt, develop root rot, or even die? Don't panic! It's most likely one of these 3 problems you overlooked. Below, we'll show you how to quickly find the cause, save the seedlings, and protect your harvest.

Cause 1: Planted too deep+too much watering, roots suffocate and rot from lack of oxygen

Beginners often make the "deep planting, waterlogged roots" mistake: covering the stem with too much soil when planting (burying the stem more than 5cm deep), after watering the potting soil becomes waterlogged, the roots are deprived of oxygen and rot, and the leaves turn yellow and go limp.

First aid: carefully dig out the plant, let the roots dry in a ventilated spot for 1-2 hours, switch to loose soil (leaf mold +garden soil+perlite=2:2:1) and replant shallowly (with the cotyledon node touching the soil surface). Water thoroughly to settle the roots, then avoid waterlogging; wait until the top 2cm of soil dries before watering again.

Prevention: err on the shallow side rather than deep; water by the "dry-wet cycle" rule; put ceramsite at the bottom of the pot to prevent waterlogging.

Cause 2: Fine feeder roots damaged, water uptake fails

Fine feeder roots are the "main force" for water uptake; once damaged, the plant wilts quickly:

Extreme temperatures: scorching summer sun burns the roots, and low winter temperatures freeze and damage them;

Improper fertilizing: strong fertilizer or uncomposted fertilizer "burns the roots," and fine feeder roots turn black and rot.

First aid: if you over-fertilized, flush the roots with plain water to dilute it; if the temperature is unsuitable, move it to a 15-25°C environment, cut off the rotten leaves and keep the healthy branches, and stop fertilizing until new leaves emerge, then apply a light compound fertilizer.

Prevention: avoid transplanting during high-temperature /low-temperature periods, do not fertilize for 1-2 weeks after planting, and later apply light, frequent fertilizing.

Cause 3: Soil carries pathogens, causing root rot

Roots turn black and rot and the stem base becomes soft and rotted; this may be root rot caused by pathogens. The leaves turn yellow without dropping, and the whole plant tends to fall over.

Prevention: before transplanting, mix the soil with thiram /carbendazim to disinfect it, or pour boiling water over the soil to sterilize it;

Treatment: immediately pull out the diseased plants and the surrounding soil; drench the healthy seedlings with hymexazol (7once every 7 days, for 2-3 times in a row), and keep the potting soil dry and well ventilated.