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Gardening is you against the weeds

Gardening is weeding. That is the truth. If you're wondering, "Why does she carry on about weeds so often?," it is because I'm weeding and thinking about it so much. I'll bet you are, too.

On the bright side, gardeners can usually handle 80 percent of the weeding job in one big spring push around the garden. That means edging beds, pulling the largest weeds (getting as many roots as possible), hoeing the small ones and shallowly cultivating the soil. This gets things under reasonable control.

I have almost made it all the way around my large yard, carting away at least 10 cart loads of weeds. Now it's just a matter of planting and tweaking a little, right?

Alas, completing the first round is not enough. If, at this stage, we don't take the next step — to thwart all the weeds that escaped the blitz — we soon will be right back where we started. One must stop the next round of weeds from taking hold.

Gardeners block weeds in various ways. Some never mulch, but just keep hoeing, cutting off the heads of new seedlings regularly and occasionally bending to pull large weeds. Some use preventive herbicides such as Preen (read the label) that prevent weed seeds from germinating. Just remember, lots of weeds regenerate from pieces of root you left behind, and Preen and its kind do not kill existing weeds. Round-Up (among other brands) kills weeds by direct contact, but it's challenging and dangerous to use when the weeds are mixed in with plants you want to keep.

Other gardeners kill weeds by smothering – blocking the weeds from sunlight. That's what mulch does, but it's important to choose the most effective kinds of mulch and mulching techniques. The usual 3 inches of attractive, shredded bark mulch – a beautiful look in a landscape bed – won't prevent the most aggressive weeds from emerging. And other weeds land on top of the mulch and take root. So you, or a landscape firm, have to keep after it.

> Paper or plastic?

After finishing my first round of weeding this week, I will place cardboard, thick newspaper sections or black plastic on open areas around the garden, with attractive mulch on top. Around perennials and shrubs, where I want the roots to grow and find water, cardboard and paper work best. Water will eventually soak through. These also decompose over time. Many weeds will indeed poke through, and some will root on top, but these buy a lot of time before that happens.

Plastic (preferably heavy builders' plastic) and landscape fabric hold moisture in the soil for a while, and block weeds longer than paper. But plastic doesn't let rain through and can be hard to remove, years later. I do not like landscape fabric – it is tough to remove or cut through. I would only use it for a large, permanent landscape design. (Some people even use old carpeting to block weeds.) Choose your products and recycling techniques – but do something to block the new and future weeds.

> Four big brutes

After decades of identifying plants and hearing horror stories from gardeners all over our region, I nominate these four as the worst weeds in the home landscape:

Goutweed or bishop's-weed (Aegopodium podagraria) is the scourge of many landscapes. It was brought to America from Europe as a pretty groundcover, some of it variegated. It's about 14 inches tall, with leaves in three leaflets and fluffy white flower heads. It spreads by rhizomes or is passed from garden to garden. Frankly, nobody should sell it or give it away, as it is so nearly impossible to eradicate. Repeated herbicide treatments may work over a long time, but ultimately the options are large scale smothering with heavy plastic or removal of the entire soil area.

Horsetail (Equisetum) , left – also called mare's tail or scouring rush (used to scrub pots) – has been on the earth for 350 million years. The genus includes trees in some climates, but here it's a short, spiky brushlike plant with very thin leaves that give herbicides nothing to cling to. It is poisonous to horses and livestock. All the gardener can do is remove the whole plant and surrounding soil. Capture one before you have thousands.

Japanese bamboo or Japanese knotweed (Polygonum cuspidatum) isn't a bamboo but its stalks resemble bamboos. Once it was used to control soil erosion on banks, when people didn't know the true cost of aggressive, invasive plants. In spring you'll notice sturdy, reddish shoots poking up through the soil; they will eventually reach 5 to 8 feet and form fluffy seed heads. The rhizomes run deep underground and can reach 12 feet outward. Dig with huge personal effort or get a backhoe, or smother its territory with 20-foot sheets of heavy plastic.

Wild morning glory, hedge bindweed (Convolvulus arvensis) looks like a wimpy morning glory with thin stems, but don't underestimate it, as it will take over your garden. Don't ever till it, as every piece produces more plants. You can pull it forever, but pieces remain. Smothering it takes years, as the seeds live for many seasons. Repeated Round-Up works eventually, especially after the plant has flowered. Or get a backhoe and replace all the soil.

We each have our enemies – for me they are cinquefoil and bedstraw. Identify your tormentors, decide your control methods and persist. Gardening is weeding.

But also: Stop aiming for perfection. Gardens are ever-evolving, and weeds are always arriving. Look at the beautiful spaces you have helped to create, appreciate the amazing individual plants and ignore the rest. Stop stressing and enjoy what you have. As soon as I've spread a little cardboard, I'm going to do just that.

Sally Cunningham is a garden writer, lecturer and consultant.