Weeds tell us a great deal about our soil and the environment  In many instances they indicate what our soil lacks.  Improving the soil will undoubtedly reduce many weeds with only environmental improvements on our part necessary.

 

The following common weeds in your area can alert you to nutrient shortages or excesses and overall soil health.  Some weeds love good rich soil, while a second bloom of some weeds may show that the soil is declining.  Knowledge of what the presence of certain weeds means helps you to manage your soil in a more productive and less haphazard manner.

 

Chickweed - Good, fertile, cultivated soil.

Bindweed - Poor drainage, compacted dirt caused by tilling while wet.

Burdock - Too much lime, creating a gypsum soil.

Chicory - Excellent soil.

Cinquefoils - Hardpan.  Poor soil needing lime.

Clovers - Grow in poor soil and work to rebuild it.

Daisy - If these are growing well, the soil is too acidic.

Dandelions - Actually PRODUCE humus (as do nettles) just like

     earthworms!  Soil that won't grow them is totally unfit.

Horse Nettle - This prickly plant shows areas of crusted soil produced by

     frequent flood/drainage cycles.

Lamb's Quarters - This annual can produce up to 40,000 seeds per plant!

     They love to grow in well-manured, cultivated soil.

Mallows - Potassium excess, wet, sandy soil.

Milkweed - Moist, cultivated soils.

Mustard (includes Shepherd's Purse and Peppergrass) - Too much

     potassium and sodium, indicates hardpan.

Nightshade/Bittersweet - Poor, over-cultivated soil which has been used

     for heavy feeding crops.  These plants are POISONOUS!

Pigweed (Amaranthus spinosis) - Cultivated, light, dry sandy soil.

Plantain - Grows only in compacted soil.

Water Hemlock - Poor drainage.  This plant is POISONOUS!

Wild Carrot (Queen Anne's Lace) - Shows that poor soil is improving.  If

     the roots are well formed, there is humus.  If the roots are knotty, the

     soil is compacted, but rich.

Wild Strawberry - Same indicators as cinquefoil.

 

 

                               WEED CLASSIFICATIONS

 

The most common method of weed classification is by use of the life span of the weeds.

 

Annual Weeds

Annual weeds complete their life cycle in one year.  Most annuals depend on an abundance of seed production and proper climatic conditions for their ability to survive.  Annuals can be broken into two groups:

 

          Summer annuals - these germinate in the spring, reach full maturity

          in the summer or autumn, set seed and die by winter.

 

          Winter annuals - these germinate in the autumn, over-winter as

          seedlings, grow in the spring, set seed in the summer and die. 

          Some weeds exhibit both a summer and winter annual habit.

 

Biennial Weeds

Biennial weeds have a life span of two years.  They grow from seed, which usually germinates in the spring.  The first season is spent in storing up food, usually in short, fleshy roots.  The foliage is usually limited to formation of a rosette of leaves.  The following season the plant draws heavily upon the stored food and grows vigorously.  It produces seed in the summer or autumn and then usually dies.

 

Perennial Weeds

Perennial weeds are plants that live for more than two years.  In many cases no seed is produced the first year, but seeding occurs each following year for the life of the plant.  There are three groups of perennials:

 

          Simple perennials - these spread only by seed.  Vegetative

          reproduction can occur, however, if the roots are cut or broken, with

          each piece sending out roots and stems to form a new plant, e.g.,

          dandelion, plantain, curled dock.

 

          Bulbous perennials - these reproduce by underground bulbs as well

          as by seed.

 

          Creeping perennials - these may spread seed but also by creeping

          roots, creeping aboveground stems (stolons) or creeping

          underground stems (rhizomes).  Perennial weeds are the most

          difficult to control and require repeated cultivation, soil sterilization

          and, in some instances, by taking drastic steps of specific herbicide

          treatments.

 

 

                      COMMON WEEDS FOUND IN LAWNS

 

The suppression of weeds in the garden, and in particular in the lawn, is of the utmost importance.  Most garden weeds are native species, which prefer to grow in disturbed ground or in an open situation.  Their capacity for producing and distributing seed is such that, no matter how thoroughly and regularly the ground tended, there will always be new crops of weeds to replace those that are removed.  Therefore, regular maintenance and rigorous control is essential to keep the lawn free from weeds and looking at its very best.

 

Couch Grass (Agropyrum repens, syn. Elymus repens)

Found in beds and borders; a perennial weed that spreads by underground stems with small fibrous roots at every joint.

 

          Control - The best way to keep weeds under control is constant

          vigilance; never allow the weed to flower or set seed.  It is difficult

          to eradicate by cultivation but constant hoeing will exhaust the

          perennial root system.  Remove by hand as soon as you see them.

          Use a fork so as to avoid cutting up the stems, as even a small

          piece left in the soil will quickly start another new plant.

 

          Regular close mowing will kill off most infestations in the first

          season.  Spray with a systemic weed killer, such as one that

          contains glyphosate, as this is absorbed through the leaves of the

          plant and the active ingredient makes its way through the cells of

          the plant down to the root.  It kills these first and then the foliage

          starts to die off.

 

          In a border, mulching will help to eliminate light, which all green

          plants need to survive.  There are several effective mulches, which

          will act as a weed barrier; weed suppressing fabric, well-rotted

          manure or garden compost, bark, grass cuttings, gravel and even a

          thick layer of newspaper.

 

Creeping Buttercup (Ranunculus repens) - A spreading perennial weed that is a serious problem in lawns, as well as garden borders.  In the lawn it forms a rosette at soil level so it isn't affected by mowing.  It spreads by runners that creep along and takes root at intervals, forming new plants.  It is a very aggressive weed and can colonize large areas.

 

          Control - Never allowing the weed to flower or set seed.  This

          particular weed is sensitive to all selective weed killers so it is easy

          to control in the lawn.  Spraying with one that contains 2,4-d, such

          as Verdone, will kill this weed.  Applying lawn sand to large areas

          will help to check its growth.  Established clumps in the lawn need

          to be raked regularly before mowing so that creeping stems are

          brought up to meet the mower blades.  Spraying with weed killer

          will do the job if the weeds are in the garden border.  Spray with a

          systemic weed killer, such as one that contains glyphosate.  Spot

          treatments on lawns are not recommended, as the weed killer will

          kill the surrounding grass too.

 

Daisy (Bellis perennis) - Daisies are more of a problem in the lawn than the garden border.  They can tolerate close mowing and still flower.  They spread by seed so can colonize the lawn fairly quickly and become a nuisance.  They are relatively easy to get rid of because they are susceptible to weed killers and one application usually is enough to kill them.

 

          Control - Never allowing the weed to flower or set seed.  If

          infestations are sparse, then weed them out using a hand fork

          known as a daisy grubber (two pronged fork), to help loosen the

          roots.  Keeping the grass healthy and well fed will help to prevent

          daisies from becoming established.  In the lawn, use a weed killer

          as part of a weed-and-feed program.  Some systemic weed killers

          may kill the surrounding grass, but a weed stick, such as Elliott's

          Touchweeder, which is brushed on to the weeds leaves, won't harm

          the grass.

 

Dandelion (Taraxacum officinale) - This is a perennial weed with large rosettes and bright yellow flower head.  It is commonly found in garden borders and in lawns.  It can tolerate close mowing so hand weeding it is usually the best control method but the long taproot needs to be removed, as new plants will form from them.

 

          Control - Never allowing the weed to flower or to set seed.  Hand

          weed plants with a hand fork, removing as much of the tap root as

          possible.  A long probe, two-pronged fork is specially made for the

          purpose of removing them and is available from many good garden

          centers.  Pouring salt onto the center of the weed will kill it

          overnight, then it should be removed by hand.  Spraying with weed

          killer will do the job if the weeds are in the garden border.  In lawns

          you can also use a weed stick, such as Elliott's Touchweeder, which

          is brushed onto the weed's leaves without harming the grass.  More

          than one application may be needed for this weed.

 

Moss - Moss is a tiny non-flowering plant that is one of the most troublesome weeds in the lawn.  It is a symptom of poorly maintained grass.  To ensure permanent freedom from this unsightly moss, the basic principles of good lawn maintenance must be rigorously followed.

 

Dampness is usually the prime suspect in the spread of moss, so spring and autumn are the main periods of rapid colonization.  This is brought about by poor drainage and/or compaction.  Moisture is not the only cause, as moss can also be a common sight on sandy soils which are free-draining.  Underfeeding the lawn, over acidity, too much shade or even cutting the grass incorrectly may also cause this problem.

 

          Control - Applying a moss killer in spring and autumn, either by

          adding lawn sand or by chemical moss killer.  Lawn sand in spring

          will burn the moss, providing a boost to grass growth.  A chemical

          moss killer, such as Phostrogen Moss Killer & Lawn Tonic Soluble,

          can be used in spring and autumn and is watered into the affected

          area and then, after a couple of weeks, the dead moss is raked up

          and any bare patches reseeded.  Feeding the lawn each spring will

          encourage the healthy, strong grass to grow.  Don't cut the grass

          too short, as it can weaken it allowing moss to quickly spread.  Also

          grass that is too long, especially in damp weather, will encourage

          trailing moss to grow.  Reduce shade on the lawn if possible.  Moss

          normally occurs under trees, so remove lower branches of the tree

          to allow light onto the grass.  Scarifying and aerating the lawn in

          autumn and, if needed lightly in spring, will improve the drainage.

          This is one of the most important operations in the control of moss.

          After scarifying and aerating, top-dress the lawn, brushing it lightly

          into the soil.  Top-dressing will help build up the fertility of the soil

          and improve drainage.

 

Clover (Trifolium repens) - White clover, or Dutch clover, spreads by runners, which creep along the surface of the soil rooting at intervals and forming new plants.  It is a very aggressive weed and can colonize large areas.

 

          Control - Never allowing the weed to flower or set seed.

          Established clumps in the lawn need to be raked regularly before

          mowing so that creeping stems are brought up to meet the mower

          blades.  Keep the lawn well watered especially in dry weather.

          Apply lawn sand in spring, which will burn off the top growth, and

          vital nitrogen for clover control will then be provided.  Spray with a

          selective lawn weed killer, such as Verdone.  Treat in June or July

          and one treatment should be enough.