Tips for Weeding Your Perennials
By The National Gardening Association, Bob Beckstrom, Karan Davis Cutler, Kathleen Fisher, Phillip Giroux, Judy Glattstein, Mike MacCaskey, Bill Marken, Charlie Nardozzi, Sally Roth, Marcia Tatroe, Lance Walheim, and Ann Whitman from Gardening All-in-One For Dummies
To keep your garden perennials looking their best, you need to control weeds. Weeds rob the soil of nutrients that your flowers could be using. Controlling weeds in your flower beds isn’t difficult. Like flowers, weeds come in two main groups — annuals and perennials:
The annuals form staggering quantities of seed; some produce up to 500,000 per plant. Pull annuals out of your garden before they form seed.
Perennial weeds are harder to control. They seem to live forever and expand by sending out roots or running stems for several feet in every direction. These weeds want to conquer the world. Pulling and digging at them appears to make them mad; they seem to spread even faster in response. Perennial weeds also form seeds, so don’t ever let them get to this stage. Unfortunately, mulch doesn’t stop their roots or runners. The most effective way to dispatch perennial weeds is with an herbicide.
Practice good housekeeping habits in your garden. Remove dead and diseased leaves and stems promptly to get diseases out of the garden before they spread. Keep the flower bed clear of weeds, which may play host to diseases or insects. Clean and disinfect pruning shears and scissors (dip them in a solution of household bleach and water) after cutting diseased plants. If you smoke, wash your hands before gardening — tobacco can contain viruses that infect flowers.
When perennial weeds pop up in an established flower border, getting the herbicide on the weed but not the flowers is a challenge. Use a plastic bag to isolate the weed. Here’s how:
Cut a hole large enough to fit the weed through in the bottom of a plastic bag.
Pull the entire weed through the hole in the bottom of the bag.
Place a stone in the bottom of the bag to hold it in place.
Carefully spray herbicide into the top of the bag.
If you accidentally spray or spill some herbicide on adjoining flowers, immediately rinse them off with water.
Seal the top of the bag with a twist-tie and leave the bag in place until the weed is dead.
If your soil is loose and crumbly, a light tug is probably all you need to yank out the most stubborn weed. But in dense soil, what usually happens is that you tug at the weed and the top comes off neatly in your hand. The roots happily grow a new top, and the next time you look, the weed is back, looking refreshed and smug! To kill most weeds, you must get the root. Here’s the simplest technique to do so:
Slip the blade of your hand trowel into the ground straight down, next to the main root of the weed.
Push the trowel blade firmly against the root to loosen it.
Grab hold of the base of the leaves and pull.
Most of the time, this action gets you the whole weed — roots and all.

Gardening Glossary
annuals
Plants that complete their entire life cycle within one growing season. The plant germinates from seed, grows and blooms, and then produces seed and dies.

Gardening Glossary
biennials
A plant that take two growing seasons to complete its life cycle. It germinates and grows leaves and stems in the first year; produces flowers and fruit (seed) in the second, and then dies.

Gardening Glossary
bolt
When a plant flowers or produces seed prematurely.

Gardening Glossary
cold frame
A wooden or concrete block box in which you can grow plants or hold dormant during the cold winter months.

Gardening Glossary
cole crops
A family of vegetables, including broccoli, cabbage, cauliflower, kale, and Brussels sprouts. They thrive in cooler weather.

Gardening Glossary
complete fertilizer
Any fertilizer that contains all three of the primary nutrients, N-P-K (nitrogen, phosphorus, potassium). Phrase is based on regulations governing the fertilizer industry. Does not mean that the fertilizer literally contains everything a plant needs to thrive.

Gardening Glossary
deadheading
The practice of pinching or cutting off spent flowers

Gardening Glossary
evaporative-pad humidifier
A humidifier in which fans blow across a moisture-laden pad that sits in a reservoir of water.

Gardening Glossary
harden off
The process of acclimating plants grown indoors gradually to the brighter light and cooler temperatures of the outside world.

Gardening Glossary
hardiness
The ability of a plant to survive is called its hardiness.

Gardening Glossary
humus
A stable end product of organic-matter decomposition that's believed to increase microbial activity in soil, improve soil structure, and enhance the root development of plants.

Gardening Glossary
Bacillus thuringiensis Bt
An effective bacteria that attacks only the larvae of caterpillar family insects. It is safe to other insects, animals, and humans.

Gardening Glossary
macronutrients
Mineral nutrients that plants need in the largest quantities: nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur.

Gardening Glossary
mulch
Organic or inorganic material placed over the surface of soil, usually directly over the root zone of growing plants. Used to conserve moisture, kill weed seedlings, modify soil temperature, provide attractive covering to garden beds.

Gardening Glossary
organic matter
Once-living stuff like compost, sawdust, animal manure, ground bark, grass clippings, and leaf mold (composted tree leaves). Used to enrich soil and improve soil texture.

Gardening Glossary
perennials
Any plant with a life cycle of three or more years. Herbaceous (non-woody) perennials include flowering plants and herbs, mainly. Woody perennials include trees and shrubs. Longevity depends on the plant and growing conditions.

Gardening Glossary
pH
The measure of soil's acidity. Soil with low pH means it's too acidic; soil with high pH means it's alkaline. Most plants grow best in soil with a pH value between 6.5 and 7.2. Neutral soils measure 7.

Gardening Glossary
photosynthesis
The process through which plants take nutrients from the air and from the water in the soil to produce sugars that fuels the plant's growth.

Gardening Glossary
primary nutrients
Nitrogen, phosphorous, and potassium are the three nutrients plants need in the largest quantities.

Gardening Glossary
root crops
Plants with edible underground roots such as onions, carrots, beets, potatoes, turnips. Most root crops are cold-weather crops.

Gardening Glossary
self-blanching
A type of cauliflower with leaves that naturally curl over the head and exclude light. Requires cool temperatures for leaves to curl effectively.

Gardening Glossary
sets
Small onion bulbs, about 1/2-inch wide, that were started from seed the previous year. Grow onion sets with the pointy end up.

Gardening Glossary
side-dressing
The act of adding a small amount of fertilizer around or "on the side" of plants after they're growing.

Gardening Glossary
succession planting
Planting small, 2-to-4-foot patches of plants every two weeks throughout the growing season so that you can harvest a crop over an extended period of time.

Gardening Glossary
thinning
The act of cutting the least robust seedlings in your garden to give the healthier plants more room to grow.

Gardening Glossary
vining crops
Crops that grow on vines, such as cucumbers, melons, pumpkins, and winter squash. They usually require support (staking, trellising, etc.) to keep them off the ground.