Coastal and Tropical South
Plant Bush and Pole Beans
It's time to plant beans of all sorts. Pole beans make more beans in the long run, but most bush beans will be ready to pick sooner. Sow seeds of green, purple, and yellow bush beans at one inch intervals in rows 6 inches apart. Plant pole beans at the base of teepee structures or every 2 inches along a fence trellis. Make a note to harvest horticultural and shelley beans while their pods are still soft for the best taste.
Square foot gardeners know all about interplanting to make the most of limited space, and this technique has other benefits too. Rows or patches of radishes between taller cabbage and broccoli use the space and stifle weeds at the same time. When you space tomatoes 3 feet apart, you gain better air circulation around each cage and leave room for squash plants in between. A third reason to interplant is for nematode control. So long as marigolds are growing in a space, the nematodes will stay elsewhere. If you have sandy soil, which can favor nematodes, consider planting marigolds among the tomato plants this year.
It may sound obvious, but the faster you snatch a weed from among the desirable plants, the more likely you are to be rid of it. Weeding by hand can take time, but it works especially well between rainstorms while the soil is damp. Dirty fingernails are okay, but textured gloves are easy to get used to and safer for your hands. Tease weeds out; don't jerk them up if their underground parts are also reproductive. I use a pointed tool to make lifting easier and keep a bucket nearby to collect the sprigs for the trash, not the compost pile.
Spread Compost around Plants
Virtually every shrub and perennial in the garden can use a compost top dressing around its base now. No matter what else you use for fertilizer or when you use it, March is a good time to feed the soil with an organic blanket. Lay the compost or compost/manure an inch deep around shrubs from the trunk out to the drip line. Scratch the compost and any decomposed mulch under the plants into the soil and top with a fresh layer of mulch such as ground bark or pine straw.
Allow Space for Big Vegetable Plants
Cantaloupe and watermelon vines, corn and cucumbers (except container varieties) all need lots of garden space to produce their best. Plan a corn "corner" in the southwest corner of the garden to send its shade away from other vegetable plants. Make the corner at least 4 feet x 4 feet, or 4 rows of plants, each a foot apart and 4 feet long. Whenever possible, trellis or otherwise raise melons and cucumbers up for bigger leaves, better air circulation, and cleaner fruit. Merliton vines need the largest trellises, at least 6 feet tall and 4 feet wide for each vine.