Aphids are common pests
in Colorado gardens.They
transmit plant diseases, deform and curl leaves, and produce sticky
honeydew that attracts ants.Often,
you can readily spot them clustered along stems, buds and leaves.Many aphids are green, although they may be other colors such as
pink or black.Some have
wings; some are wingless.
Fortunately, natural
predators such as lacewings, ladybird beetles, syrphid flies, and other
“good bugs” can control aphid populations.A strong spray of water from the garden hose is often effective
in removing them.Insecticidal
soap is also a popular remedy, and, when necessary, stronger chemical
controls are available.
Annuals
A
plant that completes its life cycle within one year is called an annual.A seed germinates and grows into a plant. The plant flowers,
produces seeds, and dies all within the span of a growing season.Some popular annuals are petunias, lobelia, marigolds and
zinnias.
Aspen Trees
The beauty of aspen trees has
enticed many homeowners who live along Colorado’s Front Range to plant
them in urban and suburban landscapes.Alas, the growing conditions of these sites are far from
ideal for this mountain native.Aspen
can be grown in urban/suburban areas, but they will be short-lived and
have many problems.
Aspen trees need acidic, light soil that drains well.If you have heavy clay soil you should plant the trees on a berm
(mound) of soil that has been well amended with organic matter.Also, try to place the trees on the north or east side of the
house where they will have some protection from intense heat and
sunlight.
You should expect the trees to
have problems with insects and diseases.(You can find books about this topic!)Some preventative measures to take are avoiding overhead
watering, providing good air circulation by how you space the trees, and
clearing away diseased leaves when they drop.Also, dormant oils that help to control diseases are available.
Bare-root
Deciduous
shrubs and trees as well as some perennial flowers, fruits and vegetables that
are sold with all the soil removed from their roots are referred to as
bare-root.These plants are sold while they are dormant in winter and early
spring, often at a sizeable savings over plants in containers.Select plants with healthy-looking, plump roots.Before planting, soak the roots overnight in a bucket of water.To plant, spread them out over a mound of soil in the planting hole.
Beneficial
Insects
Gardeners are gradually
becoming aware that many insects and bugs do not harm gardens.In fact, some insects and bugs benefit the garden by feeding on
garden pests such as aphids and mites.This group is known as “beneficial insects.”Some well known beneficial insects are ladybird beetles (lady
bugs), green lacewings, and syrphid flies.Beneficial insects are present naturally in the garden.You can purchase them by mail order or at garden centers, but
keep in mind that when you release them, they may or may not stay in
your yard.Because
insecticides kill both good bugs and bad bugs you should use chemical
controls only when absolutely necessary.
Bracts
Bracts
are modified leaves.They
are quite colorful on poinsettias, dogwoods, bougainvilleas and other
plants and are often called “flowers.”
Cool-season
Grasses
Cool-season grasses grow vigorously in periods of cooler
temperatures such as fall and spring.Generally, they tolerate cold winters well.Growth slows down during hot summer months.Some cool-season grasses are Kentucky bluegrass, perennial
ryegrass and tall fescue.
Core
Aeration
Core aeration, also know as core cultivation, is a process that removes
2-3 inch long plugs of soil and thatch from the lawn. It benefits
the lawn by reducing soil compaction, controlling thatch build-up, and
improving water and air penetration. Spring and fall are the best
times of the year to core aerate your lawn. It is good to let the
plugs disintegrate on the lawn so the nutrients can enrich the soil.
Crown
The crown of a plant is the point where the roots and the upper portion
of the plant meet.
Disbudding
Disbudding is a technique that
gardeners use to promote the production of large-sized flowers.Some plants, such as chrysanthemums, tend to produce many
small-sized buds that are forced to compete for food, light and space.As a result, these buds develop into small-sized flowers.When gardeners remove some of the buds (disbud), the remaining
buds have the food, light and space they need to become large-sized
flowers.
Dormant
A plant that is in a stage during which it
does
not actively grow is said to be dormant.
Deadheading
To
keep plants blooming as long as possible deadhead (pinch or cut off) old
blossoms before they form seeds.The plants, in an ongoing effort to produce seeds, will continue
to produce flowers.
Harden Off
Seedlings of annual and
perennial flowers need to adjust gradually to the outdoor site where
they will be planted.Young
plants are not used to bright sunlight and varying temperatures because
they are started inside in a greenhouse. To help them make the
transition to life outdoors, you should harden them off.Set them outdoors for several hours in direct sunlight each day
for a week, gradually increasing the amount of time they spend outdoors.After hardening off they are ready for planting.
Hardy
Hardiness refers to a
plant’s ability to tolerate frost and cold temperatures.
Integrated Pest
Management (IPM)
Informed gardeners realize that totally
wiping out all insects in the garden is both unwise and
unfeasible. Pest management, rather than complete eradication of
pests, is the goal. An integrated approach that utilizes a
combination of methods to keep pests in check is employed. These
techniques include
1)Cultural controls: the use of gardening practices that promote
healthy plants, such as crop rotation, proper fertilization and
watering, good garden clean-up, etc.
2)Mechanical controls: the use of barriers, traps, handpicking of
pest, etc.
3)Biological controls: the use of natural predators (beneficial
insects) such as ladybugs and green lacewings
4)Chemical controls (the last resort):the use of pesticides derived from natural sources and, when
necessary, synthetic sources.
The use of IPM
diminishes the need for chemicals and results in gardens that are safer
for everyone—children, pets, birds, butterflies, and gardeners!
Lawn
Fertilization
There are three primary
nutrient elements that plants need:nitrogen (N), phosphorus (P), and potassium (K).A “complete,” or “balanced,” fertilizer contains all
three elements.When you
look at bags or containers of fertilizer you usually will see the
percentage of each element listed as a number.For example, if a 20-pound package of fertilizer has the
numbers 15-10-5, the package of fertilizer contains 15 percent nitrogen,
10 percent phosphate (phosphorus), and 5 percent potash (potassium).That is, it has three pounds of nitrogen:20 lbs. x 15% (.15) = 3 pounds.It has two pounds of phosphate:20 lbs. x 10% (.10) = 2 pounds. It
has one pound of potash:20
lbs. x 5% (.05) = 1 pound.
If you want to apply this
fertilizer at the recommended rate of one pound of nitrogen per 1000
square feet of Kentucky bluegrass lawn, you would use 1/3 bag of
fertilizer per 1000 square feet of lawn.
Lawn Mowing
Guidelines
Mowing height:The recommended height for all types of lawns in Colorado is
about 2 1/2 to 3 inches, with 2 inches the minimum height.Grass that is cut shorter than this is likely to have more
problems with disease, insects and weeds.It is also more likely to be stressed by drought and heat.
Frequency:How often
you need to mow the lawn depends on the lawn’s rate of growth.In other words, it varies.No
more than 1/3 of the grass blade’s height should be cut off when it is
mowed.When grass is
growing rapidly you will need to mow the lawn more frequently than
during times of slow growth.Mowing
once a week on Saturday may be a convenient routine, but it isn’t
what’s best for the lawn.
Grass clippings:Don’t collect grass clippings—unless you want them for your
compost pile.Instead, allow them to drop back on the lawn.The nitrogen and other nutrients in the clippings will enrich the
soil.Decomposition will
not be a problem if you follow the guidelines regarding the frequency of
lawn mowing.
Mountain
Pine Beetle
Outbreaks of Mountain Pine
Beetles (MPB) have been responsible for the death of millions of trees
in Colorado’s forest and yards.Ponderosa,
lodgepole, Scotch and limber pine are common targets.Trees that are under stress due to overcrowding, old age,
disease, or injury are especially susceptible to attack.Unfortunately, little can be done to save infested trees.Therefore, preventive action to control the spread of MPB is
important.Homeowners may want to spray prized trees in their landscape.Infested trees must be disposed of properly to prevent the spread
of this pest. The Colorado State Forest Service and Colorado State
University Cooperative Extension can provide information and advice
concerning MPB.
Mulches
There are two basic
kinds of mulches: organic and inorganic. Each has advantages
and disadvantages.
Inorganic mulches, such as
gravel and rock, don’t blow away in Colorado’s frequent windstorms.Unlike organic mulches that decompose and have to be replenished,
inorganic mulches do not require replacement.Rock and gravel retain heat, which may or may not be an asset in
certain circumstances.A
major advantage of inorganic mulches is that weed problems are largely
eliminated when they are used over weed barrier fabric.(Note: The use of plastic as a weed barrier is not recommended
because it prevents water and air from penetrating the soil.)
Organic mulches include
wood/bark chips, shredded bark, pole peelings, straw, grass clippings
and pine needles.Like
inorganic mulches, these mulches limit weeds, reduce water evaporation,
minimize soil crusting, help maintain an even soil temperature and
prevent frost heave.An
additional benefit of organic mulches is that they improve the soil when
they decompose.However,
because organic mulches use up nitrogen when they decompose, you should
watch for yellowing of leaves, one of the signs of nitrogen deficiency.Apply a complete fertilizer at the rate of two pounds per 1000
square feet.(A complete
fertilizer contains nitrogen, phosphate and potash.)
You can mulch beds and borders
anytime if the mulch is being used to control weeds, maintain soil
temperature or improve appearance.When mulch is used to prevent frost heave, apply it after the
ground has frozen.A layer
3 to 4 inches deep is recommended.Avoid piling mulch against tree trunks and at the base of shrubs
as this can lead to problems with insects and disease.
Organic
Matter
Material that originates
from a living organism (plant or animal) is called organic matter.Examples include manure, compost (commercial or “homemade”),
peat moss, ground bark, leaf mold, sawdust, straw and pine needles.
Perennials
Plants that live from year to year and do
not have woody stems are called herbaceous perennials.Typically, these plants die down during the winter months and then
grow back in the spring;
therefore, you don’t have to replant them each
year as with annuals.Because
perennials live in the same spot for several years it is especially
important to prepare the soil well prior to planting.Common perennials include columbine, penstemon, purple coneflower
and pincushion flower.
Root-bound
A
plant becomes root-bound when it is in a container too long.When the growing roots have no place to go, they become matted
and intertwined at the bottom of the container and begin to encircle the
plant.Eventually, the
plant’s vigor declines and the plant may even die.
Root-ball
A plant’s roots and the soil they are growing in form the plant’s
root-ball.
Root
Zone
A plant’s root zone is the area throughout which the plant’s roots
extend.
Rooting
Hormone
Rooting
hormones are chemicals that stimulate the growth of roots on cuttings.They come in both powder and liquid forms.
Soil
Amendments
Soil amendments are
organic and/or inorganic materials that are worked into the soil to
improve its texture, or tilth, thereby promoting root growth.Examples of organic matter include compost, peat moss and aged
barnyard manure.Examples of inorganic materials are perlite, coarse sand, and
gypsum.Generally, soil
amendments do not act as fertilizers because they contain limited plant
nutrients.Some common
amendments, such as lime, are not suited to Colorado’s soils.Others, such as gypsum and sand, are useful only in special
circumstances and if used inappropriately, can worsen soil conditions.
Spider
Mites
Spider mites are a common pest in Colorado.Because they are smaller than a pinhead and feed on the underside
of leaves, gardeners often aren’t aware of their presence. Webbing on
plants and yellowed, bronze-colored, stippled or deformed leaves are
symptoms of infestation.Leaves,
stems and buds tend to dry out and turn brown.Outbreaks occur primarily during hot, dry weather and are more
prevalent on plants that aren’t well watered.To prevent problems with mites, provide adequate water for plants
and hose plants off periodically.You
can treat infestations with insecticidal soap or, if necessary, with
miticides that are available for use on some plants.Avoid the use of insecticides – many don’t kill spider mites.Instead, they kill off natural predators of mites, resulting in
even greater populations of this pest!
Sunscald
Sudden
fluctuations of temperature and water loss during winter can damage the
bark of young, thin-barked trees by killing new tissue.Sunscald injury usually appears on the southwest side of trees.Damaged bark changes color, becoming reddish, orange or yellow.It cracks and sheds off, making the trunk highly susceptible to
insects and diseases, such as borers and canker.This can lead to the death of the tree.Young honeylocust, birch, maple, crabapple and other thin-barked
trees can be protected from sunscald by providing adequate water during
winter and using tree wrap for the first two or three years after trees
are planted.
Thatch
Thatch is a spongy layer of living and dead grass roots and stems that
builds up between the soil and grass. Kentucky bluegrass is prone
to accumulating thatch, while buffalo grass and tall fescue seldom have
it. Once the thatch layer has become fairly thick, the grass will
take root in it rather than in the soil. This leads to problems
because the roots are unable to absorb water and nutrients properly from
the soil. If the thatch layer is greater than 1/2 inch, steps
should be taken to remedy the situation. See Core Aeration.
Tomato
Terminology
Determinate: This type of tomato produces only one crop that
comes in over a period of a week to ten days.
Indeterminate:This type of tomato produces tomatoes throughout the growing
season, right up until frost.These vigorous plants require cages or stakes.
V/F/T/N:These initials on tomato plant labels indicate that a plant is a
hybrid that has bred-in resistance to a specific tomato disease or pest.V – Verticillium wilt, F – Fusarium wilt, T – Tobacco
mosaic, N – Nematodes.
Tree
Wrap
Commercial
tree wrap is a roll of corrugated paper that is used for wrapping the
trunks of young trees to prevent sunscald.Trees should be wrapped in October or November.Start at the bottom of the tree and wind your way up the trunk.Secure the top and bottom with stretchable tape.Do not use string or other materials that could bind or cut into
the trunk of the tree as is grows.Be sure to remove the tree wrap in April.Leaving the tree wrap on during summer restricts growth and the
wrap can house insects and disease.
Warm-season
Grasses
Warm season grasses
thrive in the hot weather of summer but go dormant and turn brown in
cool or cold weather.Some
warm-season grasses are Buffalo grass, Blue Grama and Bermuda grass.
Whiteflies
Whiteflies
are common pests on houseplants.During the summer they can become pests in the garden outside as
well.Whiteflies weaken and stunt the growth of plants by sucking out
the sap.Leaves become stippled, turn yellow, and drop off.Yellow or white sticky traps, such as Tanglefoot and Tack-trap,
can be used to control whiteflies.Also, you can hose off plants with insecticidal soap or use
products containing neem or pyrethrum.Fortunately, whiteflies cannot over-winter outdoors in Colorado because
freezing temperatures kill them. Therefore, in many situations outdoors,
chemical control may not be
warranted.
Winter Watering
Unfortunately, Colorado’s
winters are too cold to leave the automatic sprinkler system on, but too
dry for lawns and many trees and shrubs.Without sufficient water, plants will die or be damaged.Therefore, it is necessary to continue watering after your
sprinkler system has been winterized in the fall.If there is no rain or snow cover for four to six weeks you
should water.Water in the
morning on days when the temperature is above freezing and when the
ground isn’t frozen so the water will be absorbed.Use a lawn sprinkler to water lawns and established trees.A soil-needle attachment on the hose works well for watering
shrubs.
Winterizer
Fertilizer
Fertilizing lawns in the fall is a
highly recommended lawn care practice.Winterizer fertilizers are used in the fall (late-season) because
they provide a number of benefits to lawns:better fall and winter color, earlier green-up of the lawn in
spring, better root growth, and increased grass density.To be effective, the fertilizer should be applied when the soil
is moist, while the lawn is still green and before the ground freezes.Winterizer fertilizer may be applied to Kentucky bluegrass,
ryegrass and tall fescue lawns at a rate of one pound of nitrogen per
1000 square feet of lawn during October or early November.Do not fertilize Buffalograss, Blue Grama or Bermuda grass in the
fall.
