Growing onions is simple: If you can poke a hole into the ground, you can grow an onion from a little plant. Our onions are seedlings in bare-root bundles; each plant will start growing within days after you plant. If you can’t plant your onions right away, remove their bindings and place them in a bucket with 2 inches of moist soil in the bottom. Keep them in a cool, bright place but out of direct sun until you are ready to plant. A sunny basement is ideal.
Growing onions requires abundant sun and good drainage, and they grow best when the soil pH ranges between 6.0 and 6.8. Raised beds or raised rows made by mounding up soil are ideal, especially if your soil is heavy clay. Mix a 2-inch layer of compost into the soil before placing an organic or timed-release fertilizer into planting furrows, following label rates. Set plants 1 inch deep, so that their roots are well covered with soil but the top of the plant’s neck is not buried too deeply. You don’t want the part of the neck where the leaves grow away from the clear sheath to collect soil or water down between the young leaves, or they can rot. Space plants 6 inches apart in furrows 12 inches apart. Plants will appreciate a starter solution of liquid fertilizer after planting.
Onions roots are shallow and not very efficient at taking up moisture, so they need a steady supply of water to grow without interruption. Although they actually recover well from drought and start growing again when watered, it is best to keep the soil consistently moist until the bulbs enlarge.
You may mulch with a light layer of weed-free and herbicide-free grass clippings or another fine mulch. Onions naturally push toward the surface as they form bulbs, and it’s best if the tops of the bulbs are allowed to bask in dry sun. Remove mulch that might keep the expanding bulbs excessively moist.
Seedlings that are about the diameter of a pencil produce the biggest, most beautiful bulbs, so some gardeners sort seedlings by size before planting. Plant the largest ones together only 2 inches apart to start enjoying as green onions in just two or three weeks. Very small seedlings set at close spacing can serve as a second crop of scallions. Use the pencil-sized plants to grow full-sized onions that will produce extra-juicy slices.
Source: Growing Onions
Cutting seed potatoes is not necessary to do before planting them. Whether to cut them or not is a personal choice for a home gardener. On one hand, cutting your seed potatoes will help you to stretch your seed potatoes a bit so that you can grow more potatoes plants but, on the other hand, cutting seed potatoes increases the chances of disease and rot.
If you decide to cut your seed potatoes, cut them into pieces so that each piece has at least one eye (though more than one eye per piece is fine too) and is roughly at least an ounce. Then allow the seed potatoes pieces to cure in a cool but humid place for 2-3 days. You can also sprinkle the cut seed potatoes with an anti-fungal powder at this time. After curing, they should be planted as soon as possible.
Planting seed potatoes at the right time is important. Seed potatoes growing in soil that is too cold and wet may rot while potatoes that grow in soil that is too warm, may not produce well. It is best to plant seed potatoes after the chance of hard frost has past, but while you are still experiencing light frosts.
Plant the seed potatoes about 2-3 inches deep and about 24 inches apart. Light frost may kill any new growth above the soil line once they sprout, but do not panic. This will not kill the potatoes plant and the potatoes will regrow their foliage quickly.
Now that you know these few tips on cutting and planting seed potatoes, you can look forward to a successful potato harvest.
Source: Growing Seed Potatoes