Have you been told that the weak seedlings are your fault? Don't believe it.
Seed sellers are deliberately silent about iodine so that you buy more fertilizers.
A drop of iodine per liter of water - and your tomatoes will overtake your neighbors in a week.

Spray the seedlings with the solution, and the leaves will become thicker and the stems will become stronger. Iodine kills phytophthora spores and speeds up the metabolism in plants.
But there is a nuance: you need to water only at the roots, otherwise the solution will burn the leaves.
For peppers and eggplants, add a teaspoon of milk to the mixture - this will protect against powdery mildew.
If the seedlings are already affected by black leg, water them with iodine water (3 drops per 3 liters) - the disease will recede within 24 hours. But do not use iodine more often than once every 10 days: its excess will make the fruits hard.
The result will be visible in 48 hours: the plants will stand up straight like soldiers, and the seed sellers will start to get nervous.
For flowers, iodine is the secret to lush bloom. Dilute 1 drop in a liter of water and water the petunias - they will be covered with buds like crazy.
If the seedlings turn yellow, add a pinch of sugar to the solution - this will revive the roots.
You can also treat seeds with iodine: soak them for an hour in a weak solution (1 drop per 2 liters), and the shoots will appear a day earlier.
But do not use this method for onions and garlic - their leaves will become brittle.