Certain plants don’t do well with transplanting due to long taproots or sensitivity to transplant shock, so it’s recommended that they be directly seeded in the garden where they will grow.
A seed inoculant (or legume inoculant) introduces Rhizobium bacteria to the soil to assist in the formation of nitrogen-fixing nodules (Rhizobia) on plant roots. This is especially important if you’re growing cover crops (like field peas) and want to maximize their benefits.
While true garlic seeds do exist, garlic is rarely grown from them. Instead, the “seed garlic” sold by seed companies are full-grown garlic bulbs that you separate into individual cloves to plant.
An onion set is a small, partially grown onion (often sold several to a bag) that is ready to transplant. Unlike baby onion plants, onion sets have no leaves as they’ve been cured and stored before shipment.
It’s generally the common (or generic) name that a plant is known by the consumer. Varietal and cultivar names sometimes vary by region, so to be absolutely sure you’re buying the correct plant, always refer to the scientific name.