-this is the lowest i.e. deepest, layer in the soil profile. It consists of
the rock that served as the parent material for the soils that
formed above it.
- a fungal disease that attacks seeds and seedlings. It is
especially prominent in cool, damp conditions. Generally when
starting seeds indoors, use a sterile seeding media like
or vermiculite to avoid this problem. Also, sterilize previously
used equipment like flats, seed trays or pots by washing them with a one part
bleach and nine parts water solution.
- a plant in which flower formation is not controlled by
photoperiod (day or night length)
Plant, Short-Day Plant and
Day Neutral Plant
- plants that normally drop their leaves in autumn as a result
of shortening day lengths. Generally, these are woody plants
with simple or compound leaves such as
However, there are at least three trees that drop their needles
every fall including
bald cypress and
- a general term for a plant that is losing its vigor. Often, it
is applied in situations where a specific
cannot be identified but the tree is still suffering. For
example, a syndrome called
shade tree decline is used for trees with
thinning foliage, dead branches and early fall color. Often it
is caused by soil compaction in the root zone.
- leaf bases that extend downward below the
point of insertion.
Deer have become a huge problem for landscape ornamental
plantings across much of America. Even in urban and suburban
areas, populations are expanding and they love to nibble on many
types of plants including
Lists of plants that
are supposedly "deer resistant" are available from many sources
but these must be used with caution. What deer eat will depend
on how many of them wander through your yard and how hungry they
are at the time. For most backyard landscapes, the only
effective way to minimize damage is to use a
Commercial products work fine but they must be reapplied
frequently since they wash off with rain.
slugs are the two greatest
animal pests of hostas. Deer generally eat the leaf blade and
avoid the petiole
resulting in hostas that look like stalks of celery. Slugs chew
tiny to larger holes in the blade of the leaf and may also chew
at the bottom of the petioles where they tend to hide during the
heat of the day.
- some plants have the ability to "launch" their seeds.
When the seed is ripe, the seedpod builds up pressure so
that when it opens, the seeds are thrown away from the
plant. (adj. dehiscent)
- shaped like the Greek letter delta i.e. triangular.
- leaves with with coarse, sharp teeth set perpendicular
to the margins
- drying out, such as from leaves losing moisture from
excess temperature, wind or droughty conditions.
- the process of arranging plants in the landscape to
achieve certain aesthetic or cultural goals. It involves
aspects of both Art and Plant Science. Two professions
are involved, Landscape Architecture and Landscape
- usually refers to vining plants that reach a certain
height and, then, stop growing in response to the
opening of early flowers on the vine.
- a whitish powder prepared from deposits formed
by the ancient skeletons of tiny organisms called diatoms. It is used as an
pesticide for certain
insects. The material has
a sharp edge to the particles which irritates
snails and other soft bodied pests as they crawl over
Note: Care should be taken in the use of diatomaceous
earth since the powder-like particles may be breathed in
to the lungs.
- a cotyledon is a "seed leaf" and seed bearing plants can be divided generally into
- Monocotyledons (generally grasses and grass-like
- Dicotyledons (all other seed bearing plants).
|Embryo with single cotyledon
||Embryo with two cotyledons
|Pollen with single furrow or pore
||Pollen with three furrows or pores
|Flower parts in multiples of three
||Flower parts in multiples of four or
|Major leaf veins parallel
||Major leaf veins reticulated (webbed)
|Stem vascular bundles scattered
||Stem vascular bundles in a ring
inside the bark
||Roots develop from radicle
|Secondary growth absent
||Secondary growth often present
- a condition where shoots or branches die from the tips
downward. This often indicates some sort of water
problem such as too much or too little water, root
problems or something blocking the vascular system of
the plant. It is a common symptom of
shade tree decline.
- plant cells, tissues and organs change from one state
to another during their movement from juvenile to mature
- shaped like a hand with the fingers outstretched
- plants that have separate male (staminate) and
female (pistillate) plants. An example is
must have both a male and female plant near each other
in order to produce berries on the female plant.
Examples include Kentucky Coffee Tree (Gymnocladus dioicus),
Spice Bush (Lindera) and
Katsura Tree (Cercidiphyllum).
- most plants have two sets of chromosomes (diploid) and
get one set from each parent during sexual reproduction.
diploid, triploid and
- any disturbance of the plant that interferes
with its normal structure, function, or economic value.
Diseases are generally caused by
fungi, viruses, and other related organisms.
- the various steps involved in developing a disease in
a plant. Generally, it includes three factors: 1)
susceptible host, 2) presence of the disease organism,
and 3) conditions favorable for the disease to develop.
- to encourage the development of larger blossoms on
certain species such as
roses, it may be
beneficial to remove smaller flower buds leaving only the
central or largest
bud to flower.
- flowers of plants in the
Asteraceae Family (a.k.a Compositae) have
composite flowers. The showy part on the outside of the
bloom consists of organs called
ray flowers which are
just for "show". In the
center of the bloom are the true flowers that will
develop the seeds and these are called disk flowers.
- one of the key ways to multiply (propagate) landscape
ornamental plants is to divide them into smaller pieces.
Generally, a division consists of a stem or
to part of the underground
crown along with some roots.
The resulting plants will be identical to the original
plant. This is the most common way that named
hosta division consists of part
of the crown with roots and at least one bud or leaf attached.
This subdivision of the original plant is capable of sustaining
itself and producing another plant. If one of the parts is
missing, the division will not grow. Each part of the division
results in a
clone that is identical to the original plant.
propagation by dividing parts (crown,
tubers) and planting segments capable of producing roots
dormant spray or dormant oil
or horticultural oil
- certain pests may be controlled
by applying a
pesticide while the plants are in a
non-growing i.e. dormant, phase. Perhaps the most common
example is the use of
dormant or horticultural oils for
the control of
Generally, these oils have
to be applied when the air temperature has been above 40
degrees for several days so that they will spread over
the scale and smother them. Some horticultural oils are
called summer oils and may be applied during the growing
season at a more dilute rate. Always follow label
- generally, the dormant season is that time of the year
when the plant is not in an active growth phase.
plants are considered dormant during the time
when they have dropped their leaves.
perennials are dormant when their foliage has been
killed back to the ground by frost. Bulbs are also
dormant when their foliage has died back and certain
species such as tulips and
lilies need exposure to cold
temperatures to break
dormancy and grow.
have a "rest" period where they appear to be dormant but
will resume growth if given water and/or warm temperatures.
True dormancy requires that the plant be exposed to some
specific factor such as cold for a defined period before
they will grow. Merely getting warm weather will not be
enough to trigger new growth in these plants.
- a labor intensive but valuable technique for preparing
the soils of beds and borders in the landscape.
Generally, it consists of removing the topsoil layer
(dig one), then loosening the subsoil layer below (dig
two) and finally replacing the topsoil mixed with a
large amount of organic matter (compost).
- placing a small pot inside a larger pot and,
perhaps, filling the space between the two pots with a
moisture-holding material such as sphagnum moss,
peat moss, or vermiculite.
This is done when a plant will be in place only
temporarily as with one that is to be moved shortly or
when placing a non-hardy plant in the garden before
moving it to a greenhouse for the winter.
- the term describes how water passes through
the soil. The soil is well-drained if water disappears
from a water filled planting hole in a few minutes. If water
remains in the hole after an hour, the soil is generally poorly
drained. The water itself does not damage the plants,
but standing water drives out oxygen from the soil so
roots may suffocate or be attacked by moisture loving
organisms (fungi) that cause rot.
- the drawstring effect
happens when the outside cells of a leaf multiply at a slower
rate that those in the center of the leaf. This results in a
cupping effect similar to when you pull the drawstrings on a
Hosta 'Lunar Eclipse' exhibits the drawstring
1) an informal planting of a
single species or cultivar
of plants stretching through a bed, border or
patch of lawn.
2) the movement of a
pesticide or other spray carried
by the wind from a target area to a non-target area.
Avoid this by only spraying on calm, low-wind mornings
|| - a method of fertilizing woody
plants by drilling 12 inch deep holes in the soil at equal intervals
around the plant and depositing
fertilizer in the holes.
This gets the fertilizer down to the tree roots so that
it is not used by the shallower roots of grass plants.
- simple, fleshy fruit having its single seed
enclosed in a hard or stony endocarp, as in a peach.
dry stone wall
- a wall made of loose stones that are not bonded
together with cement or motar. If
the wall is utilized as a retaining wall, plants may be
placed on top or on the face of the wall between the
cracks. These plants
are usually trailing or vine-like and are often
considered rock garden plants.
a hole in the ground filled with gravel or
rubble to receive drainage water and allow it to
percolate away into the surrounding subsoil.
any plant that produces flowers, floral parts, stems, or
leaves that are commonly preserved by air drying,
chemical drying, or pressing.
- chemical product in the form of
extremely fine textured powder, used to control
disease organisms. It is applied by blowing the powder
onto the plants
by means of
a special applicator device. This will form a
cloud of dust that settles on the surface of the plant. Since it requires no
mixing or water, this formulation is convenient to use, however, you
should never apply dusts in windy weather and always
wear a respirator to avoid inhaling the pesticide.
- this term applies to plants that are smaller than the
typical species type. Be aware that a dwarf version of a
tree that is normally 120 feet tall might still reach 20 feet in height.
- Dwarf was once the smallest
size category of hostas with a mound less than 4 inches tall. The
options by which a plant may be registered include only
Dwarf has been deleted from the list by
The American Hosta Society.
- the characteristics of a particular root system may regulate the ultimate size of a
plant. In trees, especially fruits, it has long been a
practice to graft a desirable fruiting variety onto a
rootstock that will limit its ultimate size. This is how
dwarf fruit trees are developed. This technique can also be used to
limit the size of ornamental