Whether your plant beds are overrun with weeds or you'd like them to have new designs, renovating the beds gives you a chance to improve the soil and plant again from scratch. Find out whether or not a bed's soil is low in nutrients by sending a soil sample to a university or county soil-testing department. The report will recommend the fertilizer, if any, to add. Renovating one plant bed can take from four to five days to more than three weeks, depending on how big the bed is and whether or not it is infested with weeds.
Perennial plants and bulbs return every year and can be dug up and replanted in a renovated plant bed. The best times for renovating a plant bed are spring and fall. Mark the position of perennials and bulbs with sticks during their growing season to make them simple to find if or when their foliage dies back. Dig up a perennial plant by pushing a garden fork into the soil 3 or 4 inches from the plant's base, and leverage the plant upward. Repeat this procedure all around the plant's base until the plant is out of the ground. Placing the plant on a tarpaulin prevents its roots from making a mess. Remove other perennials in the same way, and dig up bulb plants and place them on the tarpaulin. Most perennials and bulbs can survive four or five days out of the ground. Spray the plants with water, and cover them on hot sunny days to help keep them alive while you renovate their plant bed. Don't dig up shrubs unless you want to remove them permanently.
The most effective way to renovate a weed-infested bed is to spray the bed's weeds with herbicide. Glyphosate and other systemic herbicides control weeds down to their roots, preventing them from resprouting. On a dry, windless day when the weeds grow actively, put on long pants, a long-sleeved shirt, a hat, goggles, a dust or face mask and gloves, and spray the bed with a ready-to-use herbicide that is 2 percent glyphosate. Spray all the weeds' leaves and stems, and remove the weeds when they are dry, brown and withered, which usually takes about two weeks after an herbicide application. Herbicides damage desired plants as well as weeds. You can remove plants you wish to keep before renovating a weedy bed, but the weed roots might be entangled with the plant roots, causing a re-infestation of weeds later. Digging up weeds is another option for renovating a weedy bed, but it's usually impossible to remove all weed roots from soil.
Adding organic matter improves the soil in a plant bed. Fine pine bark, leaf mold, compost and peat are some of the organic materials that improve soil. Dig into the plant bed's soil to a depth of 8 to 10 inches, and remove rocks and plant debris, including roots. Starting at one end of the bed then working backward prevents you from treading on soil you've just worked. Spread a layer of organic material up to 6 inches deep across the bed, and spread other amendments or nutrients such as nitrogen, phosphorus, potassium or zinc as recommended in a soil test report. Incorporate the organic material and nutrients into the soil to a depth of 6 to 8 inches.
When the improved soil in the bed has settled, it's time to plant and mulch. Because fresh organic material can remove nitrogen from the soil, wait three or four days before replanting removed plants, or wait one to two weeks to plant if no plants will be returned to the bed. Divide perennials that have grown too large by cutting them into three or four sections with a sharp spade, and replant one of the sections in the renovated bed. The other sections can be given away or planted elsewhere in your yard. Plant the perennials at their previous soil depth, and plant bulbs at a depth two to three times their height. Plant new plants at the same soil depth at which they grew in their nursery containers, and space them according to the widths they will be when fully grown. Water the plants until the water puddles around their bases, and spread a layer of wood chips, shredded leaves, compost or other mulch 2 to 3 inches thick over the bare soil, keeping the mulch from touching plant stems.