GRAVETTE — As winter reluctantly relinquishes its hold, March is the time to green up the garden with the likes of Swiss chard, mustard, turnips and lettuce plantings, said Dr. Craig Andersen, extension horticulture specialist for the University of Arkansas Division of Agriculture.

“The first cool season candidates for planting in March are the transplants, broccoli, Brussels sprouts, cabbage, onions and Irish potatoes,” Andersen said. “This is because these plants will grow in cool soil that won’t support seed germination.”

Although the possibility of hard freezes should be past, there may be heavy frosts into April.

“Choose transplants that have healthy green leaves, especially the youngest leaves that have just expanded,” he said. “This ruledoes not apply to onion transplants; choose onion transplants with a firm base, where the roots will emerge, and leaves that are not water soaked and limp.”

Seed potatoes should be firm, with eyes that may be swollen, but not expanded as shoots. “When you cut your seed potato pieces, have three or four healthy eyes per piece. Each eye will form a shoot,” Andersen said. “Let the cut pieces air dry to heal overnight and then plant.”

Work the garden site, adding compost and amendments such as agricultural limestone to adjustthe soil pH to 6.0 or above. It’s much easier to add the amendments before the garden is planted. Add fertilizer as recommended by a soil test; this is generally 1 pound of a complete fertilizer, such as 10-20-20, per 100 square feet. A simple way to measure a pound of fertilizer is to use a pint mayonnaise jar.

Plant the transplants, allowing 1 foot between the potatoes, cabbage, broccoli and Brussels sprouts, and 6 inches between onions. Remove the transplant from the container and quickly get it into the ground, deeper than it was in the container, with good soil contact around the entire root ball. If you are using “biodegradable” containers, crack them with a gentle crush and make sure the entire container is underground or it will wick away moistureand the transplant will die. Potato seed pieces need to be planted about 4 inches deep. Onion transplants are planted shallowly so the youngest emerging leaf is above the soil line.

Andersen recommends giving all of the transplants a fertilizer boost to prevent transplant shock. Take one tablespoon of a complete soluble fertilizer high in phosphorus (10-20-10 or 20-20-20, the middle number is phosphorus), add to one gallon of water, mix and apply one cup of the solution per transplant. This stimulates root growth and gets the transplants offto a quick start.

After the transplants are in the ground, start planting the seeds.

“Check the soil temperature 1 to 2 inches below the soil surface. When it reaches 55 degrees Fahrenheit, we start planting,” he said.

Radishes, collards, kale, kohlrabi, pak choi, also known as bok choy, carrots, turnips, Swiss chard, spinach, beets and English peas are the first to be planted. These are hardy enough to withstand light frosts. Plant seed three times deeper than the diameter of the seed and space the seed out three to four seeds per foot. One of the most common gardening errors is to plant seed too thickly and too deep.

Now we can start to concentrate on planting the salad greens, lettuce from transplants or seeds, arugula, mache, cress, cilantro, dill, fennel and others, including a couple of cabbage and broccoli relatives: tatsoi and mizuna.

Be sure to allow the large plants such as dill and fennel enough room so they do not crowd and shade out the small plants like arugula.

Stand back and get that salad bowl ready, make your favorite vinaigrette because you will have some “good eats” in another month.

-Column provided by University of Arkansas Division of Agriculture Extension Service

Opinion, Pages 7 on 03/24/2010